Introduction: The mortality rate of glioma patients particularly with glioblastoma multiforme (GBM) remains high even with advancements in the multimodality treatment. This is partly due to chemoresistance of the glioma cells towards drug treatment which finally reduced the survival of GBM patients. In this study, we determined the chemosensitisation and oncogenic characteristics of ZFP36L2 in LN18 GBM cells using RNA interference (RNAi). Methods: Meta-analysis of microarray datasets was used to identify the druggable genes responsive to GBM chemosensitivity. Subsequently, the genes were validated using RNAi screening [pooled small interference RNA (siRNA)]. Temozolomide- resistant LN18 cells were used to evaluate the effects of gene silencing on chemosensitisation to the sub-lethal dose (1/10 of IC50) of temozolomide. Assays such as cell viability, proliferation, migration and invasion and apoptosis assays were carried out. The apoptosis pathway underlying chemosensitisation by ZFP36L2 siRNA was determined using a human apoptosis array kit. Statistical analyses were performed using one-way analysis of variance. Results: ZFP36L2 was identified as a potential marker of GBM based on the meta-analysis and RNAi screening. ZFP36L2 knockdown lead to 1) Apoptosis induction (p < 0.05) 2) Reduced cell migration (p < 0.05) 3) Reduced up to 82% of cell invasion (p < 0.01) and 4) Decreased cellular proliferation in siZFP36L2-treated LN18 cells. Downstream analysis showed that the sub-lethal dose of temozolomide caused major upregulation of BCL2-associated X, apoptosis regulator (BAX). Conclusion: ZFP36L2 is oncogenic and chemosensitive thus may contribute to gliomagenesis through cell proliferation, migration, invasion and apoptosis. RNAi therapy in combination with chemotherapy treatment such as temozolomide may serve as potential therapeutic approach in the future.
Two members of the species Oryctes rhinoceros nudivirus (OrNV) were detected in O. rhinoceros haplotype G beetles collected from an oil palm plantation in Kluang and a wild coconut tree in Batu Pahat (Johor, Malaysia). OrNV strain Kluang comprised 125,794 bp, encoding 125 open reading frames (ORFs), while OrNV strain Batu Pahat comprised 124,925 bp, encoding 126 ORFs.
The CRB (coconut rhinoceros beetle) haplotype was classified into CRB-S and CRB-G, based on the presence of single nucleotide polymorphisms (SNPs) in the mitochondrial cox1 gene. Mitochondrial genomes (mitogenomes) are the most widely used genetic resources for molecular evolution, phylogenetics, and population genetics in relation to insects. This study presents the mitogenome CRB-G and CRB-S which were collected in Johor, Malaysia. The mitogenome of CRB-G collected from oil palm plantations in 2020 and 2021, and wild coconut palms in 2021 was 15,315 bp, 15,475 bp, and 17,275 bp, respectively. The CRB-S was discovered in coconut and oil palms in 2021, and its mitogenome was 15,484 bp and 17,142 bp, respectively. All the mitogenomes have 37 genes with more than 99% nucleotide sequence homology, except the CRB-G haplotype collected from oil palm in 2021 with 89.24% nucleotide sequence homology. The mitogenome of Johor CRBs was variable in the natural population due to its elevated mutation rate. Substitutions and indels in cox1, cox2, nad2 and atp6 genes were able to distinguish the Johor CRBs into two haplotypes. The mitogenome data generated in the present study may provide baseline information to study the infection and relationship between the two haplotypes of Johor CRB and OrNV in the field. This study is the first report on the mitogenomes of mixed haplotypes of CRB in the field.
Mitragyna speciosa (Korth.) Havil. or locally known as ketum/daun sebiak/biak-biak belongs to Rubiaceae family and generally occurs in secondary forest or disturbed areas in tropical and subtropical region. This research enumerated the characterisation of Mitragyna speciosa leaf anatomy and micromorphology features which is still not well documented. This medium to large sized tree species characterised with opposite arrangement, ovate-acuminate leaf and with 12-17 pairs of veins. Transverse sections of petioles showed that this species has petiole outlines with slightly convex at the middle of the adaxial part and 'U'-shaped on abaxial side. Results also showed that this species has paracytic and hypostomatic stomata, combination of non-glandular (majority) and glandular trichomes (minority), with observation on the secretory cells present in petiole and midrib parenchyma cells. Cuticle on the abaxial and adaxial epidermal surfaces showed the presence granule and wax films with periclinal and anticlinal walls can be differentiated clearly. The results obtained in this study can be used to providing additional systematics information of Mitragyna speciosa with the documentation of the leaf anatomy and micromorphology characters.