Displaying publications 21 - 40 of 40 in total

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  1. Cheah PL, Looi LM, Lee GE, Teoh KH, Mun KS, Nazarina AR
    Diagn Pathol, 2011;6:56.
    PMID: 21699710 DOI: 10.1186/1746-1596-6-56
    Endocervicosis in the urinary bladder is a rare benign condition. We present a case in a 37-year-old woman with classical clinical and pathological features of endocervicosis. The unusual observation of endocervical-like mucinous epithelium in continuity with the urothelium in addition to fully developed endocervicosis prompted immunohistochemical profiling of the case using antibodies to cytokeratins (AE1/AE3, CK19, CK7, CK5/6, CK20), HBME-1, estrogen receptor (ER) and progesterone receptor (PR) to assess the relationship of the surface mucinous and endocervicosis glandular epithelia. The surface mucinous epithelium, urothelium and endocervicosis glands were immunopositive for AE1/AE3, CK7 and CK19 while CK20 was only expressed by few urothelial umbrella cells. The surface mucinous epithelium was CK5/6 and HBME-1 immunonegative but showed presence of ER and PR. This was in contrast to the urothelium's expression of CK5/6 but not ER and PR. In comparison, endocervicosis glands expressed HBME-1, unlike the surface mucinous epithelium. The endocervicosis epithelium also demonstrated the expected presence of ER and PR and CK5/6 immunonegativity. The slightly differing immunohistochemical phenotypes of the surface mucinous and morphologically similar endocervicosis glandular epithelium is interesting and requires further clarification to its actual nature. The patient has remained well and without evidence of disease 18-months following transurethral resection of the lesion.
  2. Cheah PL, Looi LM, Mun KS, Abdoul Rahman N, Teoh KH
    Malays J Pathol, 2011 Dec;33(2):83-7.
    PMID: 22299207
    On integration into the host cervical keratinocyte genome, human papillomavirus (HPV) E7 protein binds pRB,releasing E2F from normally incompetent pRB-E2F complexes and allowing propagation of G1-S transition by the E2F. p16(INK4a), a tumour suppressor protein, increases in reflex response to counter this. 29 histologically re-confirmed low-grade squamous intraepithelial lesions (LSIL), 27 high-grade squamous intraepithelial lesions (HSIL) and 30 invasive cervical squamous carcinoma (SCC) were immunohistochemically stained for p16(INK4a) expression using the CINtec Histology Kit (REF 9511, mtm laboratories AG, Heidelberg, Germany) to re-affirm the notion that integration of HPV occurs predominantly in SCC and possibly HSIL and less in LSIL and normal squamous epithelium (NSqE). Implicit was also the attempt to understand the role of E2F, as indicated by p16(INK4a), in evolution of SCC from HSIL. No ethnic predilection was noted for LSIL, HSIL or SCC. Patients with SCC were significantly older by about 14-years compared with HSIL (p < 0.05) while there was no significant age difference between HSIL and LSIL. p16(INK4a) expression was significantly increased (p < 0.05) in both HSIL (88.9%) and SCC (83.3%) compared with LSIL (3.4%) and NSqE (0%); the NSqE being normal squamous epithelium noted in 17 of the LSIL, 19 HSIL and 5 SCC. From these findings there is suggestion that fundamental upstream events viz HPV integration, E7 upregulation followed by E2F activation occurs at point of transformation to HSIL and continues unrelentingly for another one to two decades before hitherto unclear factors convert a non-invasive lesion into an overtly invasive malignant counterpart. Interestingly, the occurrence of HSIL and LSIL in almost the same age group could mean that alteration from episomal to integrated form of HPV may not incur a prolonged incubation period, unlike from HSIL to SCC.
  3. Looi LM, Cheah PL, Ng MH, Yip CH, Mun KS, Rahman NA
    Asian Pac J Cancer Prev, 2010;11(3):713-6.
    PMID: 21039041
    A study was initiated to explore possible differences in handling telomere attrition in the most common lignant and benign tumours of the breast in Malaysian women. Infiltrating ductal carcinoma (IDC) and fibroadenoma (FA) represented the malignant and benign prototypes respectively. 29 IDC, 28 FA and 22 benign non-lesional control (BNL) breast tissue samples were analysed for telomerase activation using a Telomerase PCR ELISA kit (Boehringer Mannheim). In addition, 23 IDC, 12 FA and 14 BNL were subjected to telomere length determination with a TeloTAGGG Telomere Length Assay Kit (Roche Diagnostic GmbH, Germany), following digestion of genomic DNA by frequently cutting restriction enzymes RsaI and HinfI. Mean telomerase activity in IDC (A450nm=0.3338), but not FA (A450nm=0.0003) was significantly raised (p<0.05) compared with BNL (A450nm=0.0031). Similarly IDC (1.2 kb), but not FA (2.2 kb), showed significant telomere shortening (p<0.05) relative to BNL (2.9 kb). The findings imply that telomere attrition and telomerase activation differ between malignant and benign tumours of the breast and may be important for targeted therapy.
  4. Cheah PL, Looi LM, Nazarina AR, Mun KS, Goh KL
    Malays J Pathol, 2008 Dec;30(2):103-7.
    PMID: 19291919 MyJurnal
    Transaminase enzymes, alanine (ALT) and aspartate transaminase (AST), have been reported to be raised and implicated to have prognostic value in hepatocellular carcinoma (HCC). Ki67, a marker of cellular proliferative activity, has also been noted to be increased in HCC. A study was conducted at the Department of Pathology, Faculty of Medicine, University of Malaya, Kuala Lumpur to determine the possible association of proliferative activity, as determined by Ki67, with the transaminase enzymes. 31 cases of histologically diagnosed HCC who underwent tumour resection were retrieved from departmental archives. The patients' ages ranged between 40 to 79 years with a mean of 58.3 years. There was a male preponderance with M:F = 2.9:1. Ethnic Chinese formed 83.9% of the cases. 4 microm sections, cut from the formalin-fixed, paraffin-embedded tumour tissue block of each case, were immunohistochemically stained with Ki67 (DAKO monoclonal MIB-1) using the commercial DakoCytomation EnVision+System-HRP kit. The latest ALT and AST levels, assayed within 7 days prior to tumour resection, were retrieved from the patients' case records. 24 (77.4%) HCC demonstrated elevation of either ALT and/or AST. 27 (87.1%) HCC were immunopositive for Ki67. Ki67 immunoexpression was significantly correlated with raised transaminases (p<0.05). Hypothetically, the mechanism by which this phenomenon may occur may simply be release of transaminases due to destruction of hepatocytes by the cancer. Thus rising levels of the transaminases could signal a more rapid growth of the tumour and these routinely performed tests can be of prognostic value in management of HCC patients.
  5. Shahrizal TA, Prepageran N, Rahmat O, Mun KS, Looi LM
    Ear Nose Throat J, 2009 Feb;88(2):786-9.
    PMID: 19224479
    Extramedullary plasmacytoma is a rare plasma cell proliferative disorder with a predilection for the head and neck region. Occasionally, it presents as a solitary lesion in the nasal cavity. We report a case of an isolated lesion in the middle turbinate of the right nasal cavity. The lesion was completely excised via an endoscopic approach. We also review the pathology and management of plasmacytomas in general.
  6. Subramaniam B, Arshad NM, Malagobadan S, Misran M, Nyamathulla S, Mun KS, et al.
    Pharmaceutics, 2021 Mar 24;13(4).
    PMID: 33804975 DOI: 10.3390/pharmaceutics13040439
    1'-acetoxychavicol acetate (ACA) extracted from the rhizomes of Alpinia conchigera Griff (Zingiberaceae) has been shown to deregulate the NF-ĸB signaling pathway and induce apoptosis-mediated cell death in many cancer types. However, ACA is a hydrophobic ester, with poor solubility in an aqueous medium, limited bioavailability, and nonspecific targeting in vivo. To address these problems, ACA was encapsulated in a nanostructured lipid carrier (NLC) anchored with plerixafor octahydrochloride (AMD3100) to promote targeted delivery towards C-X-C chemokine receptor type 4 (CXCR4)-expressing prostate cancer cells. The NLC was prepared using the melt and high sheer homogenization method, and it exhibited ideal physico-chemical properties, successful encapsulation and modification, and sustained rate of drug release. Furthermore, it demonstrated time-based and improved cellular uptake, and improved cytotoxic and anti-metastatic properties on PC-3 cells in vitro. Additionally, the in vivo animal tumor model revealed significant anti-tumor efficacy and reduction in pro-tumorigenic markers in comparison to the placebo, without affecting the weight and physiological states of the nude mice. Overall, ACA-loaded NLC with AMD3100 surface modification was successfully prepared with evidence of substantial anti-cancer efficacy. These results suggest the potential use of AMD3100-modified NLCs as a targeting carrier for cytotoxic drugs towards CXCR4-expressing cancer cells.
  7. Abdalla YOA, Nyamathulla S, Shamsuddin N, Arshad NM, Mun KS, Awang K, et al.
    Toxicol Appl Pharmacol, 2018 10 01;356:204-213.
    PMID: 30138658 DOI: 10.1016/j.taap.2018.08.014
    1'-S-1'-acetoxychavicol acetate (ACA) has been previously reported to reduce tumor volume in nude mice, at an effective dose of 1.56 mg/kg body weight. However, the detailed toxicological profile for ACA has not yet been performed. Herein, we investigated the toxicity of intravenous administration of ACA in male and female Sprague-Dawley rats, both acutely (with single doses of 2.00, 4.00 and 6.66 mg/kg body weight, for 14 days), and sub-acutely (with weekly injections of 0.66, 1.33, and 2.22 mg/kg, for 28 days). In both toxicity studies, treatment with ACA did not affect behavior, food/water intake or body weight, nor did it induce any changes in clinically relevant hematological and biochemical parameters or mortality, suggesting that the LD50 of ACA was higher than 6.66 mg/kg body weight, regardless of sex. Sub-acutely, there was however, mild focal inflammation of kidneys and lobular hepatitis, but these were not associated with significant functional adverse effects. Therefore, the no-observed-adverse-effect level (NOAEL) for intravenous administration of ACA in the present 28-day sub-acute study was 2.22 mg/kg body weight, in both male and female rats. These findings provide useful information regarding the safety of ACA use in a healthy, non-tumor-bearing rat model.
  8. Subramaniam M, Arshad NM, Mun KS, Malagobadan S, Awang K, Nagoor NH
    Biomolecules, 2019 10 18;9(10).
    PMID: 31635311 DOI: 10.3390/biom9100626
    Cancer development and progression are extremely complex due to the alteration of various genes and pathways. In most cases, multiple agents are required to control cancer progression. The purpose of this study is to investigate, using a mouse model, the synergistic interactions of anti-cancer agents, 1'-S-1'-acetoxychavicol acetate (ACA), Mycobacterium indicus pranii (MIP), and cisplatin (CDDP) in double and triple combinations to treat chemo-sensitize and immune-sensitize breast cancer. Changes in tumor volume and body weight were monitored. Organs were harvested and stained using hematoxylin-eosin for histopathological assessment. Milliplex enzyme-linked immunosorbent assay (ELISA) was performed to determine cytokine levels, while immunohistochemistry (IHC) was conducted on tumor biopsies to verify systemic drug effects. In vivo mouse models showed tumor regression with maintenance of regular body weight for all the different treatment regimens. IHC results provided conclusive evidence indicating that combination regimens were able to down-regulate nuclear factor kappa-B activation and reduce the expression of its regulated pro-inflammatory proteins. Reduction of pro-inflammatory cytokines (e.g., IL-6, TNF-α, and IFN-ɣ) levels were observed when using the triple combination, which indicated that the synergistic drug combination was able to significantly control cancer progression. In conclusion, ACA, MIP, and CDDP together serve as promising candidates for further development and for subsequent clinical trials against estrogen-sensitive breast cancer.
  9. Zhu CZ, Ting HN, Ng KH, Mun KS, Ong TA
    Phys Eng Sci Med, 2024 Mar;47(1):61-71.
    PMID: 37843766 DOI: 10.1007/s13246-023-01341-5
    Many studies have investigated the dielectric properties of human and animal tissues, particularly to differentiate between normal cells and tumors. However, these studies are invasive as tissue samples have to be excised to measure the properties. This study aims to investigate the dielectric properties of urine in relation to bladder cancer, which is safe and non-invasive to patients. 30 healthy subjects and 30 bladder cancer patients were recruited. Their urine samples were subjected to urinalysis and cytology assessment. A vector network analyzer was used to measure the dielectric constant (Ɛ') and loss factor (Ɛ″) at microwave frequencies of between 0.2 and 50 GHz at 25 °C, 30 °C and 37 °C. Significant differences in Ɛ' and Ɛ″ were observed between healthy subjects and patients, especially at frequencies of between 25 and 40 GHz at 25 °C. Bladder cancer patients had significant lower Ɛ' and higher Ɛ″ compared with healthy subjects. The Ɛ' was negatively correlated with urinary exfoliated urothelial cell number, and Ɛ″ was positively correlated. The study achieved a receiver operating characteristic area under curve (ROC-AUC) score of 0.69099 and an optimum accuracy of 75% with a sensitivity of 80% and a specificity of 70%. The number of exfoliated urothelial cell had significant effect on the dielectric properties, especially in bladder cancer patients. Urinary dielectric properties could potentially be used as a tool to detect bladder cancer.
  10. Li Q, Zhang Y, Jin P, Chen Y, Zhang C, Geng X, et al.
    Biomed Pharmacother, 2024 Aug;177:117027.
    PMID: 38925018 DOI: 10.1016/j.biopha.2024.117027
    Chemotherapy resistance typically leads to tumour recurrence and is a major obstacle to cancer treatment. Increasing numbers of circular RNAs (circRNAs) have been confirmed to be abnormally expressed in various tumours, where they participate in the malignant progression of tumours, and play important roles in regulating the sensitivity of tumours to chemotherapy drugs. As exosomes mediate intercellular communication, they are rich in circRNAs and exhibit a specific RNA cargo sorting mechanism. By carrying and delivering circRNAs, exosomes can promote the efflux of chemotherapeutic drugs and reduce intracellular drug concentrations in recipient cells, thus affecting the cell cycle, apoptosis, autophagy, angiogenesis, invasion and migration. The mechanisms that affect the phenotype of tumour stem cells, epithelial-mesenchymal transformation and DNA damage repair also mediate chemotherapy resistance in many tumours. Exosomal circRNAs are diagnostic biomarkers and potential therapeutic targets for reversing chemotherapy resistance in tumours. Currently, the rise of new fields, such as machine learning and artificial intelligence, and new technologies such as biosensors, multimolecular diagnostic systems and platforms based on circRNAs, as well as the application of exosome-based vaccines, has provided novel ideas for precision cancer treatment. In this review, the recent progress in understanding how exosomal circRNAs mediate tumour chemotherapy resistance is reviewed, and the potential of exosomal circRNAs in tumour diagnosis, treatment and immune regulation is discussed, providing new ideas for inhibiting tumour chemotherapy resistance.
  11. Ng CH, Pathy NB, Taib NA, Ho GF, Mun KS, Rhodes A, et al.
    Asian Pac J Cancer Prev, 2014;15(18):7959-64.
    PMID: 25292095
    The significance of the single hormone receptor positive phenotype of breast cancer is still poorly understood. The use of hormone therapy has been found to be less effective for this type, which has a survival outcome midway between double positive and double negative phenotypes. The aim of this study was to investigate differences in patient and tumor characteristics and survival between double-receptor positive (ER+PR+), double receptor negative (ER-PR-) and single receptor positive (ER+PR- and ER-PR+) breast cancer in an Asian setting. A total of 1,992 patients with newly diagnosed stage I to IV breast cancer between 2003 and 2008, and where information on ER and PR were available, were included in this study. The majority of patients had ER+PR+ tumors (n=903: 45.3%), followed by 741 (37.2%) ER-PR-, 247 (12.4%) ER+PR-, and 101 (5.1%) ER-PR+ tumors. Using multivariate analysis, ER+PR- tumors were 2.4 times more likely to be grade 3 compared to ER+PR+ tumors. ER+PR- and ER-PR+ tumors were 82% and 86% respectively less likely to be grade 3 compared with ER-PR- tumors. ER-PR+ tumours were associated with younger age. There were no survival differences between patients with ER+PR+ and ER-PR+ tumors. However, ER+PR- tumors have poorer survival compared with ER+PR+ tumours. ER-PR- tumours had the worst survival. Adjuvant hormonal therapy with tamoxifen was found to have identical survival advantage in patients with ER+PR+ and ER-PR+ tumors whereas impact was slightly lower in patients with ER+PR- tumors. In conclusion, we found ER+PR- tumors to be more aggressive and have poorer survival when compared to ER+PR+ tumors, while patients with ER-PR+ tumours were younger, but had a similar survival to their counterparts with ER+PR+ tumours.
  12. Roethlisberger M, Jayapalan RR, Hostettler IC, Bin Abd Kadir KA, Mun KS, Brand Y, et al.
    World Neurosurg, 2020 Jan;133:381-391.e2.
    PMID: 31476461 DOI: 10.1016/j.wneu.2019.08.102
    BACKGROUND: Data on the endonasal endoscopic approach (EEA) to treat sellar/parasellar synchronous tumors remain sparse. This work aims to describe a minimally invasive approach with intraoperative magnetic resonance imaging (MRI) to remove a large sellar/parasellar synchronous tumor, and presents a systematic literature review.

    METHODS: The preoperative MRI of a 54-year-old woman revealed a sellar lesion (28 × 19 × 16 mm), presumably a pituitary macroadenoma, and a second extra-axial lesion (22 × 36 × 20 mm) expanding from the tuberculum sellae to the planum sphenoidale with encasement of the anterior communicating complex, presumably a meningioma. We used intraoperative MRI to assess the extent of the resection before reconstructing the large skull base defect. Furthermore, we systematically reviewed pertinent articles retrieved by a PubMed/Embase database search between 1961 and December 2018.

    RESULTS: Out of 63 patients with synchronous tumors reported in 43 publications, we found 3 patients in which the tumor was removed by EEA. In these 3 patients and the presented case, the resection of both lesions was successful, without major approach-related morbidity or mortality. More extensive removal of endonasal structures to gain an adequate tumor exposure was not necessary. We did not find any previous reports describing the benefits of intraoperative MRI in the presented setting.

    CONCLUSIONS: In the rare case of a synchronous meningioma and pituitary adenoma of the sellar region, intraoperative MRI might be beneficial in confirming residual disease before skull base reconstruction, and therefore radiologic follow-up.

  13. Poh ME, Liam CK, Mun KS, Chai CS, Wong CK, Tan JL, et al.
    Thorac Cancer, 2019 09;10(9):1841-1845.
    PMID: 31350945 DOI: 10.1111/1759-7714.13156
    Adjuvant chemotherapy has long been indicated to extend survival in completely resected stage IB to IIIA non-small cell lung cancer (NSCLC). However, there is accumulating evidence that chemotherapy or chemoradiotherapy can induce epithelial-to-mesenchymal transition (EMT) in disseminated or circulating NSCLC cells. Here, we describe the first case of EMT as the cause of recurrence and metastasis in a patient with resected stage IIB lung adenosquamous carcinoma after adjuvant chemotherapy. We review the literature and explore the possible mechanisms by which EMT occurs in disseminated tumor cells (DTC) or circulating tumor cells (CTC) in response to adjuvant chemotherapy (cisplatin) as a stressor. We also explore the possible therapeutic strategies to reverse EMT in patients with recurrence. In summary, although adjuvant cisplatin-based chemotherapy in resected NSCLC does extend survival, it may lead to the adverse phenomenon of EMT in disseminated tumor cells (DTC) or circulating tumor cells (CTC) causing recurrence and metastasis.
  14. Perumal K, Mun KS, Yap NY, Razack AHA, Gobe GC, Ong TA, et al.
    Biomed Res Int, 2020;2020:3682086.
    PMID: 32802842 DOI: 10.1155/2020/3682086
    Background: The mechanisms that link obesity and cancer development are not well-defined. Investigation of leptin and leptin receptor expressions may help define some of the mechanisms. These proteins are known for associating with the immune response, angiogenesis and, signalling pathways such as JAK2/STAT3, PI3K, and AKT pathways. Tissue proteins can be easily detected with immunohistochemistry (IHC), a technique widely used both in diagnostic and research laboratories. The identification of altered levels of leptin and leptin receptor proteins in tumour tissues may lead to targeted treatment for cancer.

    Objective: The objective of this study was to use IHC to compare leptin and leptin receptor expressions in clear cell renal cell carcinomas (ccRCC) in non-obese and obese patients to determine the association between these proteins with the clinicopathological features and prognosis of ccRCC. Patients and Methods. The study involved 60 patients who underwent nephrectomy of which 34 were obese, as assessed using body mass index (BMI). Nephrectomy samples provided tissues of ccRCC and adjacent non-cancerous kidney. The intensity and localization of leptin and leptin receptor protein expressions were evaluated using IHC and correlated with clinicopathological features and clinical outcomes. Aperio ImageScope morphometry and digital pathology were applied to assess the IHC results. The chi-square test was used to determine if there was any significant association between the proteins and the clinicopathological features. The Kaplan-Meier test was used to determine the overall survival, disease-free survival, and recurrence-free survival. A value of p < 0.05 was considered significant.

    Results: There was neither significant difference in the overall cellular and nuclear expressions of leptin and leptin receptor between non-cancerous kidney and ccRCC tissues nor in non-obese and obese individuals with ccRCC.

    Conclusion: In this present study, it was revealed that leptin and leptin receptor were not associated with tumour characteristics and progression of ccRCC patients. Interestingly, nuclear expression of leptin was significantly associated with overall survival. However, the significance of these proteins as biomarkers in other RCC histotypes is still unclear.

  15. Zainal NS, Lee BKB, Wong ZW, Chin IS, Yee PS, Gan CP, et al.
    Cancer Biol Med, 2019 May;16(2):264-275.
    PMID: 31516747 DOI: 10.20892/j.issn.2095-3941.2018.0257
    Objective: Lack of effective therapies remains a problem in the treatment of oral squamous cell carcinoma (OSCC), especially in patients with advanced tumors. OSCC development is driven by multiple aberrancies within the cell cycle pathway, including amplification of cyclin D1 and loss of p16. Hence, cell cycle inhibitors of the CDK4/6-cyclin D axis are appealing targets for OSCC treatment. Here, we determined the potency of palbociclib and identified genetic features that are associated with the response of palbociclib in OSCC.

    Methods: The effect of palbociclib was evaluated in a panel of well-characterized OSCC cell lines by cell proliferation assays and further confirmed by in vivo evaluation in xenograft models. PIK3CA-mutant isogenic cell lines were used to investigate the effect of PIK3CA mutation towards palbociclib response.

    Results: We demonstrated that 80% of OSCC cell lines are sensitive to palbociclib at sub-micromolar concentrations. Consistently, palbociclib was effective in controlling tumor growth in mice. We identified that palbociclib-resistant cells harbored mutations in PIK3CA. Using isogenic cell lines, we showed that PIK3CA mutant cells are less responsive to palbociclib as compared to wild-type cells with concurrent upregulation of CDK2 and cyclin E1 protein levels. We further demonstrated that the combination of a PI3K/mTOR inhibitor (PF-04691502) and palbociclib completely controlled tumor growth in mice.

    Conclusions: This study demonstrated the potency of palbociclib in OSCC models and provides a rationale for the inclusion of PIK3CA testing in the clinical evaluation of CDK4/6 inhibitors and suggests combination approaches for further clinical studies.

  16. Yee PS, Zainal NS, Gan CP, Lee BKB, Mun KS, Abraham MT, et al.
    Target Oncol, 2019 04;14(2):223-235.
    PMID: 30806895 DOI: 10.1007/s11523-019-00626-8
    BACKGROUND: Given that aberrant activation of epidermal growth factor receptor family receptors (ErbB) is a common event in oral squamous cell carcinoma, and that high expression of these receptor proteins is often associated with poor prognosis, this rationalizes the approach of targeting ErbB signaling pathways to improve the survival of patients with oral squamous cell carcinoma. However, monotherapy with the ErbB blocker afatinib has shown limited survival benefits.

    OBJECTIVES: This study was performed to identify mechanisms of afatinib resistance and to explore potential afatinib-based combination treatments with other targeted inhibitors in oral squamous cell carcinoma.

    METHODS: We determined the anti-proliferative effects of afatinib on a panel of oral squamous cell carcinoma cell lines using a crystal violet-growth inhibition assay, click-iT 5-ethynyl-2'-deoxyuridine staining, and cell-cycle analysis. Biochemical assays were performed to study the underlying mechanism of drug treatment as a single agent or in combination with the MEK inhibitor trametinib. We further evaluated and compared the anti-tumor effects of single agent and combined treatment by using oral squamous cell carcinoma xenograft models.

    RESULTS: In this study, we showed that afatinib inhibited oral squamous cell carcinoma cell proliferation via cell-cycle arrest at the G0/G1 phase, and inhibited tumor growth in xenograft mouse models. Interestingly, we demonstrated reactivation of the mitogen-activated protein kinase (ERK1/2) pathway in vitro, which possibly reduced the effects of ErbB inhibition. Concomitant treatment of oral squamous cell carcinoma cells with afatinib and trametinib synergized the anti-tumor effects in oral squamous cell carcinoma-bearing mouse models.

    CONCLUSIONS: Our findings provide insight into the molecular mechanism of resistance to afatinib and support further clinical evaluation into the combination of afatinib and MEK inhibition in the treatment of oral squamous cell carcinoma.

  17. Dean SJ, Perks CM, Holly JM, Bhoo-Pathy N, Looi LM, Mohammed NA, et al.
    Am J Clin Pathol, 2014 Mar;141(3):323-33.
    PMID: 24515759 DOI: 10.1309/AJCPR11DEAYPTUSL
    OBJECTIVES: To investigate the association between PTEN loss and IGFBP2 expression in a series of triple-negative breast cancers and to relate this expression to basal cytokeratin expression and clinicopathologic features.

    METHODS: One hundred and one formalin-fixed and paraffin-processed triple-negative breast cancer cases from the University of Malaya Medical Centre were tested immunohistochemically for cytokeratins 5/6 and 14, PTEN, and IGFBP2. The resulting slides were scored for proportion and intensity of staining.

    RESULTS: Loss of tumor nuclear and cytoplasmic staining for PTEN occurred in 48.3% of cases and was significantly associated with younger age at diagnosis (47 years compared with 57 years in those without PTEN loss; P = .005). Independent predictors of PTEN loss were late stage at presentation (P = .026), cytokeratin 5/6 positivity (P = .028), and IGFBP2 expression (P = .042). High levels of IGFBP2 expression were seen in 32% of cases; an independent predictor of high levels was cytokeratin 14 negativity (P = .005). PTEN loss and high levels of IGFBP2 expression were associated with poorer survival, but neither of these trends was significant.

    CONCLUSIONS: PTEN loss is a frequent event in triple-negative breast cancers and is significantly associated with younger age at onset of breast cancer, late stage, and IGFBP2 expression.

  18. Foo JC, Jawin V, Yap TY, Ahmad Bahuri NF, Ganesan D, Mun KS, et al.
    Childs Nerv Syst, 2021 05;37(5):1573-1580.
    PMID: 33580355 DOI: 10.1007/s00381-021-05080-4
    PURPOSE: Multidisciplinary team meetings (MDTMs) are essential in the clinical management of pediatric central nervous system (CNS) tumors. Evaluations of the impact of MDTMs on childhood CNS tumors and clinicians' perspectives on their effectiveness are scarce.

    METHODS: We retrospectively reviewed the clinical data of pediatric patients (aged <18 years) with CNS tumors diagnosed and treated in the Pediatric Hematology-Oncology Division at the University Malaya Medical Center from 2008 to 2019. We also conducted a web-based survey of the core members of the multidisciplinary team to evaluate the impact of the MDTMs.

    RESULTS: During the pre-MDTM era (2008-2012), 29 CNS tumors were diagnosed and treated, and during the MDTM era (2014-2019), 49 CNS tumors were diagnosed and treated. The interval for histologic diagnosis was significantly shorter during the MDTM era (p=0.04), but the interval from diagnosis to chemotherapy or radiotherapy and the 5-year overall survival of the 78 patients did not improve (62.1% ± 9.0% vs. 68.8% ± 9.1%; p=0.184). However, the 5-year overall survival of patients with medulloblastoma or rare tumors significantly improved in the MDTM era (p=0.01). Key factors that contributed to delayed treatment and poor outcomes were postoperative complications, the facility's lack of infrastructure, poor parental education about early treatment, cultural beliefs in alternative medicine, and infection during chemotherapy. Eighteen clinicians responded to the survey; they felt that the MDTMs were beneficial in decision-making and enhanced the continuity of coordinated care.

    CONCLUSION: MDTMs significantly reduced the diagnostic interval and improved the overall outcomes. However, delayed treatment remains a major challenge that requires further attention.

  19. Rajagopal R, Leong SH, Jawin V, Foo JC, Ahmad Bahuri NF, Mun KS, et al.
    J Pediatr Hematol Oncol, 2021 Oct 01;43(7):e913-e923.
    PMID: 33633029 DOI: 10.1097/MPH.0000000000002116
    BACKGROUND: A higher incidence of pediatric intracranial germ cell tumors (iGCTs) in Asian countries compared with Western countries has been reported. In Malaysia, the literature regarding pediatric iGCTs have been nonexistent. The aim of this study was to review the management, survival, and long-term outcomes of pediatric iGCTs at a single tertiary center in Malaysia.

    PATIENTS AND METHODS: We retrospectively reviewed data from patients below 18 years of age with iGCTs treated at the University Malaya Medical Center (UMMC) from 1998 to 2017.

    RESULTS: Thirty-four patients were identified, with a median follow-up of 3.54 years. Sixteen (47%) patients had pure germinoma tumors (PGs), and the remaining patients had nongerminomatous germ cell tumors (NGGCTs). The median age was 12 years, with a male:female ratio of 4.7:1. Abnormal vision, headache with vomiting, and diabetes insipidus were the commonest presenting symptoms. Twenty-eight patients received initial surgical interventions, 24 were treated with chemotherapy, and 28 received radiotherapy. Eight patients experienced relapses. The 5- and 10-year event-free survival rates were similar at 61.1%±12.6% and 42.9%±12.1% for PG and NGGCT, respectively. The 5- and 10-year overall survival rates were the same at 75.5%±10.8% and 53.3%±12.3% for PG and NGGCT, respectively. Four patients died of treatment-related toxicity. Most of the survivors experienced good quality of life with satisfactory neurologic status.

    CONCLUSIONS: The survival rate of childhood iGCTs in UMMC was inferior to that reported in developed countries. Late diagnosis, poor adherence to treatment, and treatment-related complications were the contributing factors. Although these results highlight a single institution experience, they most likely reflect similar treatment patterns, outcomes, and challenges in other centers in Malaysia.

  20. Wang C, Zainal NS, Chai SJ, Dickie J, Gan CP, Zulaziz N, et al.
    Front Immunol, 2021;12:763086.
    PMID: 34733290 DOI: 10.3389/fimmu.2021.763086
    HPV-independent head and neck squamous cell carcinoma (HNSCC) is a common cancer globally. The overall response rate to anti-PD1 checkpoint inhibitors (CPIs) in HNSCC is ~16%. One major factor influencing the effectiveness of CPI is the level of tumor infiltrating T cells (TILs). Converting TILlow tumors to TILhigh tumors is thus critical to improve clinical outcome. Here we describe a novel DNA vaccines to facilitate the T-cell infiltration and control tumor growth. We evaluated the expression of target antigens and their respective immunogenicity in HNSCC patients. The efficacy of DNA vaccines targeting two novel antigens were evaluated with or without CPI using a syngeneic model. Most HNSCC patients (43/44) co-expressed MAGED4B and FJX1 and their respective tetramer-specific T cells were in the range of 0.06-0.12%. In a preclinical model, antigen-specific T cells were induced by DNA vaccines and increased T cell infiltration into the tumor, but not MDSC or regulatory T cells. The vaccines inhibited tumor growth and improved the outcome alone and upon combination with anti-PD1 and resulted in tumor clearance in approximately 75% of mice. Pre-existence of MAGED4B and FJX1-reactive T cells in HNSCC patients suggests that these widely expressed antigens are highly immunogenic and could be further expanded by vaccination. The DNA vaccines targeting these antigens induced robust T cell responses and with the anti-PD1 antibody conferring excellent tumor control. This opens up an opportunity for combination immunotherapy that might benefit a wider population of HNSCC patients in an antigen-specific manner.
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