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The current state of understanding of oncology expanded access programs in Malaysia

Yong FL, Tan WC

Med J Malaysia, 2024 Mar;79(2):191-195.
PMID: 38553925

INTRODUCTION: An expanded access program (EAP) is a regulatory mechanism that provides access to an investigational drug, which is not approved for use, in treating life-threatening conditions when all the standard-ofcare treatments are exhausted.
MATERIALS AND METHODS: An online, anonymous, voluntary survey was conducted to assess the level of knowledge and understanding about EAPs among Malaysian oncologists using SurveyMonkey® between April 2020 and June 2020. Oncologists who had enquired about EAP in the past, were invited at random to participate in the survey. Participants who did not provide consent or failed to complete the survey were excluded.
RESULTS: A total of 15 oncologists participated in the survey, from both public (46.6%) and private (46.6%) practices. Most respondents (80%) had filed between 1 to 10 EAP applications in the past 12 months. For 73.3% respondents, resources or training were not provided for EAPs from institutions. Around 53% of the respondents reported that their knowledge of EAPs and application processes including country regulations is 'good'. The majority of respondents (73.3%) reported that the educational modules on an overview of EAPs, country regulations and the EAP application process will be beneficial. Most participants received information about the existing EAPs either by reaching out to a pharmaceutical sponsor or through another health care provider and some received information about the existing EAPs through their institutions or patients/caregivers. Most of the respondents recommended that pharmaceutical companies should have readily available information related to the availability and application of EAPs for all pipeline products on their websites.
DISCUSSION: EAPs are crucial treatment access pathways to provide investigational drugs to patients who have exhausted their treatment options and are not eligible for participation in clinical trials. Malaysian oncologists have a fair understanding about the EAPs and the application processes.
CONCLUSION: Additional training and awareness are needed for Malaysian oncologists to upscale the utilisation of EAPs.
Fulltext Potentiality of a triple microRNA classifier: miR-193a-3p, miR-23a and miR-338-5p for early detection of colorectal cancer

Yong FL, Law CW, Wang CW

BMC Cancer, 2013 Jun 08;13:280.
PMID: 23758639 DOI: 10.1186/1471-2407-13-280

BACKGROUND: MicroRNAs (miRNAs) are short, non-coding RNA molecules that act as regulators of gene expression. Circulating blood miRNAs offer great potential as cancer biomarkers. The objective of this study was to correlate the differential expression of miRNAs in tissue and blood in the identification of biomarkers for early detection of colorectal cancer (CRC).
METHODS: The study was divided into two phases: (I) Marker discovery by miRNA microarray using paired cancer tissues (n = 30) and blood samples (CRC, n = 42; control, n = 18). (II) Marker validation by stem-loop reverse transcription real time PCR using an independent set of paired cancer tissues (n = 30) and blood samples (CRC, n = 70; control, n = 32). Correlation analysis was determined by Pearson's test. Logistic regression and receiver operating characteristics curve analyses were applied to obtain diagnostic utility of the miRNAs.
RESULTS: Seven miRNAs (miR-150, miR-193a-3p, miR-23a, miR-23b, miR-338-5p, miR-342-3p and miR-483-3p) have been found to be differentially expressed in both tissue and blood samples. Significant positive correlations were observed in the tissue and blood levels of miR-193a-3p, miR-23a and miR-338-5p. Moreover, increased expressions of these miRNAs were detected in the more advanced stages. MiR-193a-3p, miR-23a and miR-338-5p were demonstrated as a classifier for CRC detection, yielding a receiver operating characteristic curve area of 0.887 (80.0% sensitivity, 84.4% specificity and 83.3% accuracy).
CONCLUSION: Dysregulations in circulating blood miRNAs are reflective of those in colorectal tissues. The triple miRNA classifier of miR-193a-3p, miR-23a and miR-338-5p appears to be a potential blood biomarker for early detection of CRC.
Fulltext MicroRNA expression profile of a Malaysian Bajau family with familial mitochondrial neurogastrointestinal encephalomyopathy

Yong FL, Wang CW, Tan KS

Genet. Mol. Res., 2015;14(4):13172-83.
PMID: 26535630 DOI: 10.4238/2015.October.26.13

Mitochondrial neurogastrointestinal encephalomyopathy (MNGIE) is a rare, autosomal recessive disorder associated with mutations in the thymidine phosphorylase (TYMP) gene. The main objective of this study was to characterize the genetic profiles of the deceased proband's family members (N = 4) using DNA sequencing and to determine miRNA deregulation in MNGIE using miRNA microarray profiling and bioinformatic analysis. We found that the genetic profile of the younger sister showed similar TYMP gene mutations as that of the proband with the exception of a heterozygous mutation in exon 10. The miRNA microarray revealed 55 significantly up-regulated and 65 significantly down-regulated miRNAs. These miRNAs have been implicated in various mitochondrial dynamics such as energy metabolism, Krebs cycle, mitochondria-associated apoptosis, and mitophagy. In conclusion, we demonstrate that blood miRNAs are deregulated in the pathogenesis of MNGIE and these changes may have therapeutic implications. Further experimental studies will be required to elucidate the functional miRNA-mRNA interactions in MNGIE.
Fulltext The involvement of miR-23a/APAF1 regulation axis in colorectal cancer

Yong FL, Wang CW, Roslani AC, Law CW

Int J Mol Sci, 2014 Jul 02;15(7):11713-29.
PMID: 24992592 DOI: 10.3390/ijms150711713

Recent advances in microRNAome have made microRNAs (miRNAs) a compelling novel class of biomarker in cancer biology. In the present study, the role of miR-23a in the carcinogenesis of colorectal cancer (CRC) was investigated. Cell viability, apoptosis, and caspase 3/7 activation analyses were conducted to determine the potentiality of apoptosis resistance function of miR-23a in CRC. Luciferase assay was performed to verify a putative target site of miR-23a in the 3'-UTR of apoptosis protease activating factor 1 (APAF1) mRNA. The expression levels of miR-23a and APAF1 in CRC cell lines (SW480 and SW620) and clinical samples were assessed using reverse transcription-quantitative real-time PCR (RT-qPCR) and Western blot. We found that the inhibition of miR-23a in SW480 and SW620 cell lines resulted in significant reduction of cell viability and promotion of cell apoptosis. Moreover, miR-23a up-regulation was coupled with APAF1 down-regulation in CRC tissue samples. Taken together, miR-23a was identified to regulate apoptosis in CRC. Our study highlights the potential application of miR-23a/APAF1 regulation axis in miRNA-based therapy and prognostication.
Fulltext MicroRNAs regulating cluster of differentiation 46 (CD46) in cardioembolic and non-cardioembolic stroke

Tan JR, Tan KS, Yong FL, Armugam A, Wang CW, Jeyaseelan K, et al.

PLoS One, 2017;12(2):e0172131.
PMID: 28199366 DOI: 10.1371/journal.pone.0172131

Ischemic stroke is a major cause of mortality and morbidity globally. Among the ischemic stroke subtypes, cardioembolic stroke is with poor functional outcome (Modified Rankin score ≥ 2). Early diagnosis of cardioembolic stroke will prove beneficial. This study examined the microRNAs targeting cluster of differentiation 46 (CD46), a potential biomarker for cardioembolic stroke. CD46 mRNA level was shown to be differentially expressed (p < 0.001) between cardioembolic stroke (median = 1.32) and non-cardioembolic stroke subtypes (large artery stroke median = 5.05; small vessel stroke median = 6.45). Bioinformatic search showed that miR-19a, -20a, -185 and -374b were found to target CD46 mRNA and further verified by luciferase reporter assay. The levels of miRNAs targeting CD46 were significantly reduced (p < 0.05) in non-cardioembolic stroke patients (large artery stroke median: miR-19a = 0.63, miR-20a = 0.42, miR-185 = 0.32, miR-374b = 0.27; small artery stroke median: miR-19a = 0.07, miR-20a = 0.06, miR-185 = 0.07, miR-374b = 0.05) as compared to cardioembolic stroke patients (median: miR-19a = 2.69, miR-20a = 1.36, miR-185 = 1.05, miR-374b = 1.23). ROC curve showed that the miRNAs could distinguish cardioembolic stroke from non-cardioembolic stroke with better AUC value as compared to CD46. Endogenous expression of CD46 in Human Umbilical Vein Endothelial Cells (HUVECs) were found to be regulated by miR-19a and miR-20a. Thus implicating that miR-19a and -20a may play a role in pathogenesis of cardioembolic stroke, possibly via the endothelial cells.