Displaying publications 41 - 60 of 602 in total

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  1. Jaafar H, Abdullah S, Murtey MD, Idris FM
    Asian Pac J Cancer Prev, 2012;13(8):3857-62.
    PMID: 23098483
    A total of 96 cases of invasive breast ductal carcinoma were examined for immunohistochemical expression of Bax and Bcl-2 in the epithelial tumor cells and endothelial cells of the blood vessels. We also investigated the association between both proteins in the epithelium in relation to tumor characteristics such as tumor size, grade, lymph node involvement, microvessel density (MVD), hormonal receptors expression and c-erbB-2 overexpression. Bax expression showed a significant association between tumor and endothelial cells (p<0.001) while Bcl-2 expression in tumor cells was inversely associated with that in the endothelial cells (p<0.001). Expression of Bcl-2 in tumor cells was strongly associated with expression of estrogen and progesterone receptors (p=0.003 and p=0.004, respectively). In addition, intratumoral MVD was significantly higher than peritumoral MVD (p<0.001) but not associated with Bax or Bcl-2 expression and other tumor characteristics. We concluded that the number of endothelial cells undergoing apoptosis was in direct linkage with the number of apoptotic tumor cells. Anti-apoptotic activity of the surviving tumor cells appears to propagate cancer progression and this was influenced by the hormonal status of the cells. Tumor angiogenesis was especially promoted in the intratumoral region and angiogenesis was independent of anti-apoptotic activity.
    Matched MeSH terms: Breast Neoplasms/metabolism*
  2. Siew EL, Chan KM, Williams GT, Ross D, Inayat-Hussain SH
    Free Radic. Biol. Med., 2012 Oct 15;53(8):1616-24.
    PMID: 22687461 DOI: 10.1016/j.freeradbiomed.2012.05.046
    The Fau gene (Finkel-Biskis-Reilly murine sarcoma virus (FBR-MuSV)-associated ubiquitously expressed gene) was identified as a potential tumor suppressor gene using a forward genetics approach. Downregulation of Fau by overexpression of its reverse sequence has been shown to inhibit apoptosis induced by DNA-damaging agents. To address a potential role of Fau in benzene toxicity, we investigated the apoptotic effects of hydroquinone (HQ), a major benzene metabolite, in W7.2 mouse thymoma cells transfected with either a plasmid construct expressing the antisense sequence of Fau (rfau) or the empty vector (pcDNA3.1) as a control. HQ induced apoptosis via increased production of reactive oxygen species and DNA damage, measured using dihydroethidine (HE) staining and alkaline Comet assay, respectively, in W7.2 pcDNA3.1 cells. In contrast, when Fau was downregulated by the antisense sequence in W7.2 rfau cells, HQ treatment did not cause DNA damage and oxidative stress and these cells were markedly more resistant to HQ-induced apoptosis. Further investigation revealed that there was an upregulation of NAD(P)H: quinone oxidoreductase 1 (NQO1), a detoxification enzyme for benzene-derived quinones, in W7.2 rfau cells. Compromising cellular NQO1 by use of a specific mechanism-based inhibitor (MAC 220) and NQO1 siRNA resensitized W7.2 rfau cells to HQ-induced apoptosis. Silencing of Fau in W7.2 wild-type cells resulted in increased levels of NQO1, confirming that downregulation of Fau results in NQO1 upregulation which protects against HQ-induced apoptosis.
    Matched MeSH terms: Thymus Neoplasms/metabolism
  3. Chong HZ, Rahmat A, Yeap SK, Md Akim A, Alitheen NB, Othman F, et al.
    PMID: 22471785 DOI: 10.1186/1472-6882-12-35
    Strobilanthes crispus has been traditionally used as antidiabetic, anticancer, diuretic, antilytic and laxative agent. However, cytotoxicity and antiproliferative effect of S. crispus is still unclear.
    Matched MeSH terms: Breast Neoplasms/metabolism
  4. 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.
    Matched MeSH terms: Uterine Cervical Neoplasms/metabolism
  5. Azrif M, Ibrahim J, Aslan NM, Fong KV, Ismail F
    Asian Pac J Cancer Prev, 2011;12(1):157-62.
    PMID: 21517250
    INTRODUCTION: Neoadjuvant chemotherapy for locally advanced breast cancer is given with the aim of shrinking the disease sufficiently for surgery. However, many clinical trials investigating neoadjuvant chemotherapy regimens were conducted for operable breast cancer.

    METHODS AND MATERIALS: Patients with T3-4, N2 M0 breast cancer diagnosed between January 2005 and December 2008 and who received at least one cycle of neoadjuvant chemotherapy were eligible for this study. Thirty-four patients were identified from the Chemotherapy Daycare Records and their medical records were reviewed retrospectively. The neoadjuvant chemotherapy regimen administered was at the discretion of the treating oncologist. Breast tumour size and nodal status was assessed at diagnosis, at each cycle and before surgery.

    RESULTS: All 34 patients had invasive ductal cancer. The median age was 52 years (range 27-69). 65% had T4 disease and 76% were clinically lymph node positive at diagnosis. The median size of the breast tumour at presentation was 80 mm (range 42-200 mm). Estrogen and progesterone receptor positivity was seen in less than 40% and HER2 positivity, by immunohistochemistry, in 27%. The majority (85%) of patients had anthracycline based chemotherapy, without taxanes. The overall response rate (clinical CR+PR) was 67.6% and pathological complete responses were apparent in two (5.9%). 17.6% of patients defaulted part of their planned treatment. Recurrent disease was seen in 44.1% and the median time to relapse was 11.3 months. The three year disease free and overall survival rates were 52.5% and 58% respectively.

    CONCLUSION: Neoadjuvant chemotherapy for locally advanced breast cancer in a Malaysian setting confers response and pCR rates comparable to published clinical trials. Patients undergoing neoadjuvant chemotherapy are at risk of defaulting part of their treatment and therefore their concerns need to be identified proactively and addressed in order to improve outcomes.

    Matched MeSH terms: Breast Neoplasms/metabolism
  6. Vincent-Chong VK, Ismail SM, Rahman ZA, Sharifah NA, Anwar A, Pradeep PJ, et al.
    Oral Dis, 2012 Jul;18(5):469-76.
    PMID: 22251088 DOI: 10.1111/j.1601-0825.2011.01894.x
    Multistep pathways and mechanisms are involved in the development of oral cancer. Chromosomal alterations are one of such key mechanisms implicated oral carcinogenesis. Therefore, this study aims to determine the genomic copy number alterations (CNAs) in oral squamous cell carcinoma (OSCC) using array comparative genomic hybridization (aCGH) and in addition attempt to correlate CNAs with modified gene expression.
    Matched MeSH terms: Mouth Neoplasms/metabolism
  7. Lee ST, Wong PF, Cheah SC, Mustafa MR
    PLoS One, 2011;6(4):e18915.
    PMID: 21541327 DOI: 10.1371/journal.pone.0018915
    Alpha-tomatine (α-tomatine) is the major saponin in tomato (Lycopersicon esculentum). This study investigates the chemopreventive potential of α-tomatine on androgen-independent human prostatic adenocarcinoma PC-3 cells.
    Matched MeSH terms: Prostatic Neoplasms/metabolism*
  8. Chew MM, Gan SY, Khoo AS, Tan EL
    BMC Cancer, 2010;10:574.
    PMID: 20964870 DOI: 10.1186/1471-2407-10-574
    Nasopharyngeal carcinoma (NPC) is a type of neoplasm that is highly prevalent in East Asia and Africa with Epstein-Barr virus (EBV), genetic, and dietary factors implicated as possible aetiologic factors. Previous studies suggested the association of certain cytokines with the invasion and metastatic properties of NPC. The present study examined the roles of EBV latent membrane protein-1 (LMP1), interleukin-6 (IL-6), interleukin-10 (IL-10), transforming growth factor-beta 1 (TGF-β1) and laminin in the regulation of matrix-metalloproteinases (MMPs) and vascular endothelial growth factor (VEGF) in NPC. The effects of these factors on bmi-1, an oncogene, and ngx6, a tumour suppressor gene, were also investigated.
    Matched MeSH terms: Nasopharyngeal Neoplasms/metabolism
  9. Ooi KL, Tengku Muhammad TS, Lim CH, Sulaiman SF
    Integr Cancer Ther, 2010 Mar;9(1):73-83.
    PMID: 20150224 DOI: 10.1177/1534735409356443
    The chloroform extract of Physalis minima produced a significant growth inhibition against human T-47D breast carcinoma cells as compared with other extracts with an EC(50) value of 3.8 microg/mL. An analysis of cell death mechanisms indicated that the extract elicited an apoptotic cell death. mRNA expression analysis revealed the coregulation of apoptotic genes, that is, c-myc , p53, and caspase-3. The c-myc was significantly induced by the chloroform extract at the earlier phase of treatment, followed by p53 and caspase-3. Biochemical assay and ultrastructural observation displayed typical apoptotic features in the treated cells, including DNA fragmentation, blebbing and convolution of cell membrane, clumping and margination of chromatin, and production of membrane-bound apoptotic bodies. The presence of different stages of apoptotic cell death and phosphatidylserine externalization were further reconfirmed by annexin V and propidium iodide staining. Thus, the results from this study strongly suggest that the chloroform extract of P. minima induced apoptotic cell death via p53-, caspase-3-, and c-myc-dependent pathways.
    Matched MeSH terms: Breast Neoplasms/metabolism
  10. Seow HF, Yip WK, Loh HW, Ithnin H, Por P, Rohaizak M
    Pathol Oncol Res, 2010 Jun;16(2):239-48.
    PMID: 19882362 DOI: 10.1007/s12253-009-9216-3
    Activation of Akt signaling pathway has been documented in various human malignancies, including breast carcinoma. The objective of this study is to determine the incidence of Akt phosphorylation in breast tumours and its relationship with expression of ER-alpha, ER-beta, HER2, Ki-67 and phosphorylated Bcl-2 associated death domain (p-BAD). Immunohistochemical staining was performed to detect these molecules on 43 paraffin-embedded breast tumour tissues with commercially available antibodies. Eighteen (41.9%), 3 (7.0%), 23 (53.5%), 35 (81.4%), 21 (48.8%), 29 (67.4%), and 34 (81.0%) of breast tumours were positive for nuclear ER-alpha, nuclear ER-beta, membranous HER2, cytonuclear p-Akt (Thr308), p-Akt (Ser473), p-BAD and Ki-67, respectively. ER-alpha expression was inversely correlated with HER2 and Ki-67 (P = 0.041 and P = 0.040, respectively). The p-Akt (Ser473) was correlated with increased level of p-BAD (Ser136) (P = 0.012). No relationship of Akt phosphorylation with HER2, ER-alpha or ER-beta was found. The p-Akt (Ser473) immunoreactivity was significantly higher in stage IV than in stage I or II (P = 0.036 or P = 0.009). The higher Ki-67 and lower ER-alpha expression showed an association with patient age of <50 years (P = 0.004) and with positive nodal status (P = 0.033), respectively. Our data suggest that the Akt phosphorylation and inactivation of its downstream target, BAD may play a role in survival of breast cancer cell. This study does not support the simple model of linear HER2/PI3K/Akt pathway in breast cancer.
    Matched MeSH terms: Breast Neoplasms/metabolism*
  11. Abdulamir AS, Hafidh RR, Kadhim HS, Abubakar F
    PMID: 19243595 DOI: 10.1186/1756-9966-28-27
    The aim of this study is to comparatively elucidate the underlying molecular pathways and clinicopathological criteria in schistosomal bladder tumor (SBT) versus non-schistosomal bladder tumor (NSBT).
    Matched MeSH terms: Urinary Bladder Neoplasms/metabolism
  12. Cheah YH, Nordin FJ, Tee TT, Azimahtol HL, Abdullah NR, Ismail Z
    Anticancer Res, 2008 Nov-Dec;28(6A):3677-89.
    PMID: 19189649
    Xanthorrhizol is a natural sesquiterpenoid compound isolated from the rhizome of Curcuma xanthorrhizza Roxb (Zingerberaceae). Recent studies of xanthorrhizol in cell cultures strongly support the role of xanthorrhizol as an antiproliferative agent. In our study, we tested the antiproliferative effect of xanthorrhizol using different breast cancer cell lines. The invasive breast cancer cell line, MDA-MB-231, was then selected for further investigations. Treatment with xanthorrhizol caused 50% growth inhibition on MDA-MB-231 cells at 8.67 +/- 0.79 microg/ml as determined by sulforhodamine B (SRB) assay. Hoechst 33258 nuclear staining assay showed the rate of apoptosis of MDA-MB-231 cells to increase in response to xanthorrhizol treatment. Immunofluorescence staining using antibody MitoCapture and fluorescein isothiocyanate (FITC)-labeled cytochrome c revealed the possibility of altered mitochondrial transmembrane potential and the release of cytochrome c respectively. This was further confirmed by Western-blotting, where cytochrome c was showed to migrate from mitochondrial fraction to the cytosol fraction of treated MDA-MB-231 cells. Caspase activity assay showed the involvement of caspase-3 and caspase-9, but not caspase-6 or caspase-8 in MDA-MB-231 apoptotic cell death. Subsequently, cleavage of PARP-1 protein is suggested. These data suggest treatment with xanthorrhizol modulates MDA-MB-231 cell apoptosis through the mitochondria-mediated pathway subsequent to the disruption of mitochondrial transmembrane potential, release of cytochrome c, activation of caspase-3 and caspase-9, and the modulation of PARP-1 protein.
    Matched MeSH terms: Breast Neoplasms/metabolism
  13. Handayani T, Sakinah S, Nallappan M, Pihie AH
    Anticancer Res, 2007 Mar-Apr;27(2):965-71.
    PMID: 17465228
    Xanthorrhizol is a sesquiterpenoid compound extracted from the rhizome of Curcuma xanthorrhiza. This study investigated the antiproliferative effect and the mechanism of action of xanthorrhizol on human hepatoma cells, HepG2, and the mode of cell death. An antiproliferative assay using methylene blue staining revealed that xanthorrhizol inhibited the proliferation of the HepG2 cells with a 50% inhibition of cell growth (IC50) value of 4.17 +/- 0.053 microg/ml. The antiproliferative activity of xanthorrhizol was due to apoptosis induced in the HepG2 cells and not necrosis, which was confirmed by the Tdt-mediated dUTP nick end labeling (TUNEL) assay. The xanthorrhizol-treated HepG2 cells showed typical apoptotic morphology such as DNA fragmentation, cell shrinkage and elongated lamellipodia. The apoptosis mediated by xanthorrhizol in the HepG2 cells was associated with the activation of tumor suppressor p53 and down-regulation of antiapoptotic Bcl-2 protein expression, but not Bax. The levels of Bcl-2 protein expression decreased 24-h after treatment with xanthorrhizol and remained lower than controls throughout the experiment, resulting in a shift in the Bax to Bcl-2 ratio thus favouring apoptosis. The processing of the initiator procaspase-9 was detected. Caspase-3 was also found to be activated, but not caspase-7. Xanthorrhizol exerts antiproliferative effects on HepG2 cells by inducing apoptosis via the mitochondrial pathway.
    Matched MeSH terms: Liver Neoplasms/metabolism
  14. Ch'ng ES, Tuan Sharif SE, Jaafar H
    Asian Pac J Cancer Prev, 2012;13(9):4445-52.
    PMID: 23167359
    BACKGROUND: Prognosis of breast cancer depends on classic pathological factors and also tumor angiogenesis. This study aimed to evaluate the clinicopathological factors of breast cancer in a tertiary centre with a focus on the relationship between tumor angiogenesis and clinicopathological factors.

    METHODS: Clinicopathological data were retrieved from the archived formal pathology reports for surgical specimens diagnosed as invasive ductal carcinoma, NOS. Microvessels were immunohistochemically stained with anti-CD34 antibody and quantified as microvessel density.

    RESULTS: At least 50% of 94 cases of invasive breast ductal carcinoma in the study were advanced stage. The majority had poor prognosis factors such as tumor size larger than 50mm (48.9%), positive lymph node metastasis (60.6%), and tumor grade III (52.1%). Higher percentages of estrogen and progesterone receptor negative cases were recorded (46.8% and 46.8% respectively). Her-2 overexpression cases and triple negative breast cancers constituted 24.5% and 22.3% respectively. Significantly higher microvessel density was observed in the younger patient age group (p=0.012). There were no significant associations between microvessel density and other clinicopathological factors (p>0.05).

    CONCLUSIONS: Majority of the breast cancer patients of this institution had advanced stage disease with poorer prognostic factors as compared to other local and western studies. Breast cancer in younger patients might be more proangiogenic.

    Matched MeSH terms: Breast Neoplasms/metabolism
  15. Lim WS, Ng DL, Kor SB, Wong HK, Tengku-Muhammad TS, Choo QC, et al.
    Cytokine, 2013 Jan;61(1):266-74.
    PMID: 23141142 DOI: 10.1016/j.cyto.2012.10.007
    Peroxisome proliferator activated receptor-alpha (PPARα) plays a major role in the regulation of lipid and glucose homeostasis, and inflammatory responses. The objectives of the study were to systematically investigate the effects of TNF-α and its regulatory pathway on PPARα expression in HepG2 cells using Real-Time RT-PCR and western blot analysis. Here, TNF-α suppressed PPARα mRNA expression in a dose- and time-dependent manner at the level of gene transcription. Pre-treatment of cells with 10μM of Wedelolactone for 2h was sufficient to restore PPARα expression to basal levels and also affected the expression of PPARα-regulated genes. This study also demonstrated that TNF-α represses PPARα expression by augmenting the activity of canonical NF-κB signalling pathway. This was shown by the abrogation of TNF-α-mediated PPARα down-regulation, after both p65 and p50 were knocked down via siRNA. The IKK contributes to IκBα degradation and mediates inducible phosphorylation of p105 at Ser933. Surprisingly, phosphorylation of p65 at Ser468 and Ser536 were severely abrogated with Wedelolactone inhibition, suggesting that Ser468 and Ser536, but not Ser276, may mediate the TNF-α inhibitory action on PPARα gene expression. These results suggest that TNF-α might, at least in part, suppress PPARα expression through activation of IKK/p50/p105/p65 pathway. Furthermore, phosphorylation of p65 at Ser468 and Ser536 may play a crucial role in the mechanism that limits PPARα production in the human HepG2 cells.
    Matched MeSH terms: Liver Neoplasms/metabolism
  16. Chai SJ, Yap YY, Foo YC, Yap LF, Ponniah S, Teo SH, et al.
    PLoS One, 2015;10(11):e0130464.
    PMID: 26536470 DOI: 10.1371/journal.pone.0130464
    Nasopharyngeal carcinoma (NPC) is highly prevalent in South East Asia and China. The poor outcome is due to late presentation, recurrence, distant metastasis and limited therapeutic options. For improved treatment outcome, immunotherapeutic approaches focusing on dendritic and autologous cytotoxic T-cell based therapies have been developed, but cost and infrastructure remain barriers for implementing these in low-resource settings. As our prior observations had found that four-jointed box 1 (FJX1), a tumor antigen, is overexpressed in NPCs, we investigated if short 9-20 amino acid sequence specific peptides matching to FJX1 requiring only intramuscular immunization to train host immune systems would be a better treatment option for this disease. Thus, we designed 8 FJX1-specific peptides and implemented an assay system to first, assess the binding of these peptides to HLA-A2 molecules on T2 cells. After, ELISPOT assays were used to determine the peptides immunogenicity and ability to induce potential cytotoxicity activity towards cancer cells. Also, T-cell proliferation assay was used to evaluate the potential of MHC class II peptides to stimulate the expansion of isolated T-cells. Our results demonstrate that these peptides are immunogenic and peptide stimulated T-cells were able to induce peptide-specific cytolytic activity specifically against FJX1-expressing cancer cells. In addition, we demonstrated that the MHC class II peptides were capable of inducing T-cell proliferation. Our results suggest that these peptides are capable of inducing specific cytotoxic cytokines secretion against FJX1-expressing cancer cells and serve as a potential vaccine-based therapy for NPC patients.
    Matched MeSH terms: Nasopharyngeal Neoplasms/metabolism
  17. Gobe GC, Ng KL, Small DM, Vesey DA, Johnson DW, Samaratunga H, et al.
    Biochem Biophys Res Commun, 2016 Apr 22;473(1):47-53.
    PMID: 26995091 DOI: 10.1016/j.bbrc.2016.03.048
    Apoptosis repressor with caspase recruitment domain (ARC), an endogenous inhibitor of apoptosis, is upregulated in a number of human cancers, thereby conferring drug resistance and giving a rationale for the inhibition of ARC to overcome drug resistance. Our hypothesis was that ARC would be similarly upregulated and targetable for therapy in renal cell carcinoma (RCC). Expression of ARC was assessed in 85 human RCC samples and paired non-neoplastic kidney by qPCR and immunohistochemistry, as well as in four RCC cell lines by qPCR, Western immunoblot and confocal microscopy. Contrary to expectations, ARC was significantly decreased in the majority of clear cell RCC and in three (ACHN, Caki-1 and 786-0) of the four RCC cell lines compared with the HK-2 non-cancerous human proximal tubular epithelial cell line. Inhibition of ARC with shRNA in the RCC cell line (SN12K1) that had shown increased ARC expression conferred resistance to Sunitinib, and upregulated interleukin-6 (IL-6) and vascular endothelial growth factor (VEGF). We therefore propose that decreased ARC, particularly in clear cell RCC, confers resistance to targeted therapy through restoration of tyrosine kinase-independent alternate angiogenesis pathways. Although the results are contrary to expectations from other cancer studies, they were confirmed here with multiple analytical methods. We believe the highly heterogeneous nature of cancers like RCC predicate that expression patterns of molecules must be interpreted in relation to respective matched non-neoplastic regions. In the current study, this procedure indicated that ARC is decreased in RCC.
    Matched MeSH terms: Kidney Neoplasms/metabolism*
  18. Alabsi AM, Lim KL, Paterson IC, Ali-Saeed R, Muharram BA
    Biomed Res Int, 2016;2016:4904016.
    PMID: 27123447 DOI: 10.1155/2016/4904016
    Dracaena cinnabari Balf.f. is a red resin endemic to Socotra Island, Yemen. Although there have been several reports on its therapeutic properties, information on its cytotoxicity and anticancer effects is very limited. This study utilized a bioassay-guided fractionation approach to determine the cytotoxic and apoptosis-inducing effects of D. cinnabari on human oral squamous cell carcinoma (OSCC). The cytotoxic effects of D. cinnabari crude extract were observed in a panel of OSCC cell lines and were most pronounced in H400. Only fractions DCc and DCd were active on H400 cells; subfractions DCc15 and DCd16 exhibited the greatest cytotoxicity against H400 cells and D. cinnabari inhibited cells proliferation in a time-dependent manner. This was achieved primarily via apoptosis where externalization of phospholipid phosphatidylserine was observed using DAPI/Annexin V fluorescence double staining mechanism studied through mitochondrial membrane potential assay cytochrome c enzyme-linked immunosorbent and caspases activities revealed depolarization of mitochondrial membrane potential (MMP) and significant activation of caspases 9 and 3/7, concomitant with S phase arrest. Apoptotic proteins array suggested that MMP was regulated by Bcl-2 proteins family as results demonstrated an upregulation of Bax, Bad, and Bid as well as downregulation of Bcl-2. Hence, D. cinnabari has the potential to be developed as an anticancer agent.
    Matched MeSH terms: Mouth Neoplasms/metabolism
  19. Takebe Y, Tsujigiwa H, Katase N, Siar CH, Takabatake K, Fujii M, et al.
    J Oral Pathol Med, 2017 Jan;46(1):67-75.
    PMID: 27327904 DOI: 10.1111/jop.12467
    BACKGROUND: Tumor parenchyma-stromal interactions affect the properties of tumors and their dynamics. Our group previously showed that secreted frizzled related protein (sFRP)-2 impairs bone formation and promotes bone invasion in ameloblastoma. However, the effects of the secreted growth factors CCN2, TGF-β, and BMP4 on stromal tissues in ameloblastoma remain unclear.

    MATERIALS AND RESULTS: Thirty-five paraffin-embedded ameloblastoma cases, ameloblastoma-derived cell lines (AM-1), and primary cultures of ameloblastoma stromal fibroblasts (ASF) were used. Immunohistochemistry, MTT assay, Western blotting, and RT-PCR were performed on these samples. Parenchyma-stromal CCN2 overexpression correlated significantly with fibrous-type stroma, but not with myxoid-type stroma, suggesting a role of CCN2 in fibrosis (P < 0.05). Recombinant CCN2 induction of enhanced ASF proliferation in AM-1 medium supports this view. Conversely, BMP4 and TGF-β were expressed in myxoid-type fibroblasts, but little expression was found in parenchyma. RANKL-positive and CD68-positive stromal cell populations were significantly greater in myxoid-type tumor areas than in fibrous-type tumor areas, while a higher Ki-67 labeling index was recorded in ameloblastoma with fibrous-type stroma. These data suggest that stromal properties influence bone resorption-related activities and growth rates, respectively.

    CONCLUSIONS: These results suggest that the effects of secreted growth factors are governed by ameloblastoma parenchyma-stromal interactions. CCN2 promotes fibrogenesis independent of TGF-β signaling. Absence of CCN2 expression is associated with a phenotypic switch to a myxoid-type microenvironment that is conducive for TGF-β/BMP4 signaling to promote osteoclastogenesis.

    Matched MeSH terms: Jaw Neoplasms/metabolism*
  20. Siar CH, Rahman ZA, Tsujigiwa H, Mohamed Om Alblazi K, Nagatsuka H, Ng KH
    J Oral Pathol Med, 2016 Sep;45(8):591-8.
    PMID: 26752341 DOI: 10.1111/jop.12417
    BACKGROUND: Cell migration and invasion through interstitial tissues are dependent upon several specialized characteristics of the migratory cell notably generation of proteolytic membranous protrusions or invadopodia. Ameloblastoma is a benign odontogenic epithelial neoplasm with a locally infiltrative behaviour. Cortactin and MMT1-MMP are two invadopodia proteins implicated in its local invasiveness. Other invadopodia regulators, namely N-WASP, WIP and Src kinase remain unclarified. This study addresses their roles in ameloblastoma.

    MATERIALS AND METHOD: Eighty-seven paraffin-embedded ameloblastoma cases (20 unicystic, 47 solid/multicystic, 3 desmoplastic and 17 recurrent) were subjected to immunohistochemistry for expression of cortactin, N-WASP, WIP, Src kinase and F-actin, and findings correlated with clinicopathological parameters.

    RESULTS: Invadopodia proteins (except Src kinase) and F-actin were widely detected in ameloblastoma (cortactin: n = 73/87, 83.9%; N-WASP: n = 59/87; 67.8%; WIP: n = 77/87; 88.5%; and F-actin: n = 87/87, 100%). Protein localization was mainly cytoplasmic and/or membranous, and occasionally nuclear for F-actin. Cortactin, which functions as an actin-scaffolding protein, demonstrated significantly higher expression levels within ameloblastoma tumoral epithelium than in stroma (P < 0.05). N-WASP, which coordinates actin polymerization and invadopodia-mediated extracellular matrix degradation, was overexpressed in the solid/multicystic subtype (P < 0.05). WIP, an upstream regulator of N-WASP, and F-actin were significantly upregulated along the tumour invasive front compared to tumour centres (P < 0.05). Except for males with cortactin overexpression, other clinical parameters (age, ethnicity and anatomical site) showed no significant correlations.

    CONCLUSIONS: Present results suggest that local invasiveness of ameloblastoma is dependent upon the migratory potential of its tumour cells as defined by their distribution of cortactin, N-WASP and WIP in correlation with F-actin cytoskeletal dynamics.

    Matched MeSH terms: Jaw Neoplasms/metabolism*
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