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Intravenous immunoglobulin-resistant Kawasaki disease: Risk factors in children in a middle-income country

Zahari N, Bah MNM, Sulieman MF, Choo HL

Ann Pediatr Cardiol, 2023;16(2):102-108.
PMID: 37767168 DOI: 10.4103/apc.apc_159_22

BACKGROUND: Identifying risk factors in patients with intravenous immunoglobulin (IVIG) resistance Kawasaki disease (KD) is vital in managing and preventing coronary artery aneurysms (CAAs). We aimed to study the risk factors for IVIG resistance KD in Malaysian children.
METHODS: This retrospective observational study of children with KD was conducted at two tertiary hospitals in Malaysia from January 2014 to December 2019. Multivariable binary logistic regression was used to analyze the risk factors associated with IVIG resistance.
RESULTS: A total of 174 patients, 118 males (67.8%) with a median age of 1.4-year-old (interquartile range: 0.1-12.1-year-old), were analyzed. Early (<5 days) and late (>10 days) IVIG treatments were observed in 14 (8.1%) and 19 (11.0%), respectively. Thirty-two patients (18.4%) had IVIG resistance. The independent factors associated with IVIG resistance were high white cell count, hypoalbuminemia, and extremities changes with an odd ratio of 4.7, 3.0, and 4.0, respectively. In addition, CAA was significantly higher in IVIG resistance compared to IVIG responder patients (57.5% [19/33] vs. 23.4% [33/141], P < 0.001). The sensitivity was high in Harada (93.8%) but low in Kobayashi and Egami (46.9% and 34.4%, respectively). The specificity was high with Egami (79.6%) but low in Harada and Kobayashi (22.5% and 64.1%, respectively).
CONCLUSION: Leukocytosis, hypoalbuminemia, and extremities changes were independent risk factors for IVIG resistance. The variation in sensitivity and specificity of the Japanese scoring makes it unsuitable for predicting IVIG resistance in Malaysian children.
Fulltext A Comprehensive Review of Cervical Cancer Screening Devices: The Pros and the Cons

Hon HJ, Chong PP, Choo HL, Khine PP

Asian Pac J Cancer Prev, 2023 Jul 01;24(7):2207-2215.
PMID: 37505749 DOI: 10.31557/APJCP.2023.24.7.2207

OBJECTIVE: The low screening coverage and reluctance of women in participation lead to low uptake in cervical screening tests. Hence the majority of cervical cancer patients visiting the hospitals are diagnosed at advanced stage, often leading to poor survival rate. This paper aims to review and compile available cancer screening devices so that more people in this field will adopt suitable devices in cervical cancer screening routine depending on requirements which may encourage the uptake in cervical screening tests.
METHODS: This paper reviews devices invented for different cervical cancer screening methods, which are Pap smear test, visual inspection with acetic acid (VIA) or Lugol's iodine (VILI), and HPV (human papillomavirus)-DNA (deoxyribonucleic acid) self-test in terms of functionality, performance in solving the limitations of screening procedure and additionally where applicable, the cervical cell collection efficacy and abnormality detection accuracy. The devices are either available in the market, published in research articles or published in international patent databases.
RESULT: The reviewed devices either simplified the screening procedure to improve the clinical efficiency and accuracy in screening, reduced the pain and discomfort experienced by women during screening procedures, or achieved both outcomes.
CONCLUSION: Many devices have been invented to improve the screening procedures which may potentially improve the uptake in cervical screening tests and encourage the organization of screening campaigns to reduce cervical cancer incidence.
Suppression of BCL-2 synergizes cisplatin sensitivity in nasopharyngeal carcinoma cells

Low SY, Tan BS, Choo HL, Tiong KH, Khoo AS, Leong CO

Cancer Lett, 2012 Jan 28;314(2):166-75.
PMID: 22033244 DOI: 10.1016/j.canlet.2011.09.025

The efficacy of cisplatin for treating nasopharyngeal carcinoma (NPC) is limited by the dose-related toxicities and the development of resistance to cisplatin. Recent studies have shown that B cell lymphoma-2 (BCL-2) is overexpressed and confers chemoresistance in NPC. Thus, targeted therapy against BCL-2 may enhance the antitumour effects of chemotherapy by sensitizing the tumor cells to undergo apoptosis. This study evaluated the combined effects of BCL-2 inhibition and cisplatin in NPC cells. Our results demonstrate that inhibition of BCL-2 by small-hairpin RNA (shRNA) or the BCL-2 inhibitor YC137, synergizes cisplatin sensitivity in NPC cells that overexpress BCL-2. We also show that YC137 enhance cisplatin-induced apoptosis in HK1 and CNE1 cells through suppression of BCL-2 protein expression, induction of mitochondrial depolarization and activation of caspase 9 and caspase 3/7. These findings suggest that the combination of BCL-2 inhibition and cisplatin represents a promising strategy for treating NPC.
Fulltext Modeling and Simulation of Additively Manufactured Cylindrical Component Using Combined Thermomechanical and Inherent Strain Method with Nelder-Mead Optimization

Taufek T, Manurung YHP, Adenan MS, Akma S, Choo HL, Louhichi B, et al.

3D Print Addit Manuf, 2023 Feb 01;10(1):156-169.
PMID: 36998800 DOI: 10.1089/3dp.2021.0197

This research concerns on the application of combined thermomechanical-inherent strain method (TMM-ISM) in predicting the distortion of additively manufactured component. The simulation and experimental verification were conducted in the form of vertical cylinder using selective laser melting, which was subsequently cut in the middle section. The setup and procedure of simulation approaches followed the actual process parameters such as laser power, layer thickness, scan strategy, and temperature dependent material, including flow curve retrieved from specialized computational numerical software. The investigation began with virtual calibration test using TMM, followed by manufacturing process simulation using ISM. Based on the maximum deformation result of simulated calibration and accuracy consideration from previous equivalent study, the inherent strain values used in ISM analysis were obtained using self-developed optimization algorithm with direct pattern search Nelder-Mead method in finding the minimum error of distortion using MATLAB. The error minima were measured between transient TMM-based simulation and simplified formulation in calculating the inherent strain values with respect to longitudinal and transverse laser directions. Furthermore, the combined TMM-ISM distortion results were compared to fully TMM with equivalent mesh number and verified based on experimental investigation conducted by renowned researcher. It can be concluded that the result of slit distortion from TMM-ISM and TMM showed good agreement with the error percentage of 9.5% and 3.5%, respectively. However, the computational time for combined TMM-ISM was reduced tremendously with only 63 min if compared to TMM with 129 min in running full simulation on solid cylindrical component. Hence, combined TMM-ISM-based simulation can be considered as an alternative method to replace time-consuming and cost-intensive calibration preparation and analysis.
Fulltext CYP2S1 and CYP2W1 mediate 2-(3,4-dimethoxyphenyl)-5-fluorobenzothiazole (GW-610, NSC 721648) sensitivity in breast and colorectal cancer cells

Tan BS, Tiong KH, Muruhadas A, Randhawa N, Choo HL, Bradshaw TD, et al.

Mol. Cancer Ther., 2011 Oct;10(10):1982-92.
PMID: 21831963 DOI: 10.1158/1535-7163.MCT-11-0391

Both 2-(4-amino-3-methylphenyl)-5-fluorobenzothiazole (5F-203; NSC 703786) and 2-(3,4-dimethoxyphenyl)-5-fluorobenzothiazole (GW-610; NSC 721648) are antitumor agents with novel mechanism(s). Previous studies have indicated that cytochrome (CYP) P450 1A1 is crucial for 5F-203 activity. In the present study, we investigated the functional role of 2 newly identified CYP P450 enzymes, CYP2S1 and CYP2W1, in mediating antitumor activity of benzothiazole compounds. We generated isogenic breast cancer (MDA-MB-468, MCF-7) and colorectal cancer (CRC; KM12 and HCC2998) cell lines depleted for CYP1A1, CYP2S1, or CYP2W1. The sensitivity of these cells to 5F-203 and GW-610 was then compared with vector control cells. 5F-203 exhibited potent activity against breast cancer cells, whereas GW-610 was effective against both breast and colorectal cancer cells. CYP1A1 was induced in both breast cancer and CRC cells, while CYP2S1 and CYP2W1 were selectively induced in breast cancer cells only following treatment with 5F-203 or GW-610. Depletion of CYP1A1 abrogated the sensitivity of breast cancer and CRC cells to 5F-203 and GW-610. Although depletion of CYP2S1 sensitized both breast cancer and CRC cells toward 5F-203 and GW-610, CYP2W1 knockdown caused marked resistance to GW-610 in CRC cells. Our results indicate that CYP-P450 isoforms, with the exception of CYP1A1, play an important role in mediating benzothiazole activity. CYP2S1 appears to be involved in deactivation of benzothiazoles, whereas CYP2W1 is important for bioactivation of GW-610 in CRC cells. Because CYP2W1 is highly expressed in colorectal tumors, GW-610 represents a promising agent for CRC therapy.
Fulltext Mutant p53-R273H mediates cancer cell survival and anoikis resistance through AKT-dependent suppression of BCL2-modifying factor (BMF)

Tan BS, Tiong KH, Choo HL, Chung FF, Hii LW, Tan SH, et al.

Cell Death Dis, 2015;6:e1826.
PMID: 26181206 DOI: 10.1038/cddis.2015.191

p53 is the most frequently mutated tumor-suppressor gene in human cancers. Unlike other tumor-suppressor genes, p53 mutations mainly occur as missense mutations within the DNA-binding domain, leading to the expression of full-length mutant p53 protein. Mutant p53 proteins not only lose their tumor-suppressor function, but may also gain new oncogenic functions and promote tumorigenesis. Here, we showed that silencing of endogenous p53-R273H contact mutant, but not p53-R175H conformational mutant, reduced AKT phosphorylation, induced BCL2-modifying factor (BMF) expression, sensitized BIM dissociation from BCL-XL and induced mitochondria-dependent apoptosis in cancer cells. Importantly, cancer cells harboring endogenous p53-R273H mutant were also found to be inherently resistant to anoikis and lack BMF induction following culture in suspension. Underlying these activities is the ability of p53-R273H mutant to suppress BMF expression that is dependent on constitutively active PI3K/AKT signaling. Collectively, these findings suggest that p53-R273H can specifically drive AKT signaling and suppress BMF expression, resulting in enhanced cell survivability and anoikis resistance. These findings open the possibility that blocking of PI3K/AKT will have therapeutic benefit in mutant p53-R273H expressing cancers.
Fulltext Fibroblast growth factor receptor 4 (FGFR4) and fibroblast growth factor 19 (FGF19) autocrine enhance breast cancer cells survival

Tiong KH, Tan BS, Choo HL, Chung FF, Hii LW, Tan SH, et al.

Oncotarget, 2016 Sep 06;7(36):57633-57650.
PMID: 27192118 DOI: 10.18632/oncotarget.9328

Basal-like breast cancer is an aggressive tumor subtype with poor prognosis. The discovery of underlying mechanisms mediating tumor cell survival, and the development of novel agents to target these pathways, is a priority for patients with basal-like breast cancer. From a functional screen to identify key drivers of basal-like breast cancer cell growth, we identified fibroblast growth factor receptor 4 (FGFR4) as a potential mediator of cell survival. We found that FGFR4 mediates cancer cell survival predominantly via activation of PI3K/AKT. Importantly, a subset of basal-like breast cancer cells also secrete fibroblast growth factor 19 (FGF19), a canonical ligand specific for FGFR4. siRNA-mediated silencing of FGF19 or neutralization of extracellular FGF19 by anti-FGF19 antibody (1A6) decreases AKT phosphorylation, suppresses cancer cell growth and enhances doxorubicin sensitivity only in the FGFR4+/FGF19+ breast cancer cells. Consistently, FGFR4/FGF19 co-expression was also observed in 82 out of 287 (28.6%) primary breast tumors, and their expression is strongly associated with AKT phosphorylation, Ki-67 staining, higher tumor stage and basal-like phenotype. In summary, our results demonstrated the presence of an FGFR4/FGF19 autocrine signaling that mediates the survival of a subset of basal-like breast cancer cells and suggest that inactivation of this autocrine loop may potentially serve as a novel therapeutic intervention for future treatment of breast cancers.
Rapamycin synergizes cisplatin sensitivity in basal-like breast cancer cells through up-regulation of p73

Wong SW, Tiong KH, Kong WY, Yue YC, Chua CH, Lim JY, et al.

Breast Cancer Res Treat, 2011 Jul;128(2):301-13.
PMID: 20686837 DOI: 10.1007/s10549-010-1055-0

Recent gene expression profiling studies have identified five breast cancer subtypes, of which the basal-like subtype is the most aggressive. Basal-like breast cancer poses serious clinical challenges as there are currently no targeted therapies available to treat it. Although there is increasing evidence that these tumors possess specific sensitivity to cisplatin, its success is often compromised due to its dose-limiting nephrotoxicity and the development of drug resistance. To overcome this limitation, our goal was to maximize the benefits associated with cisplatin therapy through drug combination strategies. Using a validated kinase inhibitor library, we showed that inhibition of the mTOR, TGFβRI, NFκB, PI3K/AKT, and MAPK pathways sensitized basal-like MDA-MB-468 cells to cisplatin treatment. Further analysis demonstrated that the combination of the mTOR inhibitor rapamycin and cisplatin generated significant drug synergism in basal-like MDA-MB-468, MDA-MB-231, and HCC1937 cells but not in luminal-like T47D or MCF-7 cells. We further showed that the synergistic effect of rapamycin plus cisplatin on basal-like breast cancer cells was mediated through the induction of p73. Depletion of endogenous p73 in basal-like cells abolished these synergistic effects. In conclusion, combination therapy with mTOR inhibitors and cisplatin may be a useful therapeutic strategy in the treatment of basal-like breast cancers.