1.Factor IX mutations in Haemophilia B patients in Malaysia: apreliminary study
Pauline Balraj ; Munirah Ahmad ; Alan Soo Beng Khoo ; Yasmin Ayob
The Malaysian Journal of Pathology 2012;34(1):67-69
Haemophilia B is caused by coagulation defects in the factor IX gene located in Xq27.1 on the X
chromosome. Identifi cation of mutations contributing to defective factor IX may be advantageous
for precise carrier and prenatal diagnosis. We studied 16 patients from 11 families, consisting
of 8 patients of the Malay ethnic group, of which 6 were siblings. Factor IX mutations have not
been previously reported in the Malay ethnic group. The functional region of the factor IX gene
was sequenced and mutations were identifi ed in either the exon or intronic regions in 15 of the
patients. One novel mutation, 6660_6664delTTCTT was identifi ed in siblings with moderate form
of haemophilia B. Mutations identifi ed in our patients when linked with disease severity were
similar to fi ndings in other populations. In summary, this preliminary data will be used to build a
Malaysian mutation database which would facilitate genetic counseling.
2.Lack of Rb2/p130 genetic alteration in Malaysian nasopharyngeal carcinoma.
Susan Ling Ling Hoe ; Ee Soo Lee ; Alan Soo Beng Khoo ; Suat-Cheng Peh
The Malaysian journal of pathology 2009;31(1):53-6
The retinoblastoma-related gene Rb2/p130 has been reported to be mutated in several malignancies such as lung cancer and Burkitt's lymphoma. Nasopharyngeal carcinoma (NPC) is a common cancer in Malaysia especially amongst the ethnic Chinese. We screened for Rb2/p130 gene (exons 19 to 21) mutations in 53 archival NPC samples via PCR-SSCP-direct sequencing approach. Only one sample had a base change which involved a serine to glycine substitution at codon 995 (S995G). We conclude that Rb2/p130 genetic alterations are infrequent in NPC and may not be essential for the pathogenesis of the disease.
Genetic
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MALAYSIAN
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Genes
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Carcinoma
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Malignant Neoplasms
3.Molecular analysis of 2009 pandemic Infl uenza A(H1N1) in Malaysia associated with mild and severe infections
Pauline BALRAJ ; Huraizah SIDEK ; Jeyanthi SUPPIAH ; Alan Soo Beng KHOO ; Zainah SAAT
The Malaysian Journal of Pathology 2011;33(1):7-12
The 2009 pandemic infl uenza A(H1N1) was fi rst detected in Malaysia in May 2009. It quickly
spread in the general population and contributed to a number of infl uenza-like illness. The objective
of the study is to characterize genetic changes in early Malaysian isolates of mild and severe illness
of the novel infl uenza, and to compare sequences of viruses circulating in Malaysia to those in other
countries between May to September 2009. Viral isolates of 56 mild cases and 10 severe (intensive
care unit or fatal) cases were sequenced for haemagglutinin (HA) and neuraminidase (NA). Genome
sequencing of the viral RNA was conducted on 5 isolates (3 were from fatal cases). Highly conserved
sequences with few sporadic variations were identifi ed in HA and NA. E374K and D222N were
identifi ed in 2 viral isolates from patients with severe illness. Phylogenetic analysis showed close
genetic relatedness to the vaccine strain A/California/07/09 and other isolates circulating worldwide
during the same period. Sporadic variations were identifi ed in the viral isolates, however a larger
sample size is required to make associations with disease severity.
4.Expression Trend of Selected Ribosomal Protein Genes in Nasopharyngeal Carcinoma
Xiang-Ru Ma ; Edmund Ui-Hang Sim ; Teck-Yee Ling ; Thung-Sing Tiong ; Selva Kumar Subramaniam ; Alan Soo-Beng Khoo
Malaysian Journal of Medical Sciences 2012;19(4):23-30
Background: Ribosomal proteins are traditionally associated with protein biosynthesis until recent studies that implicated their extraribosomal functions in human diseases and cancers. Our previous studies using GeneFishingTM DEG method and microarray revealed underexpression of three ribosomal protein genes, RPS26, RPS27, and RPL32 in cancer of the nasopharynx. Herein, we investigated the expression pattern and nucleotide sequence integrity of these genes in nasopharyngeal carcinoma to further delineate their involvement in tumourigenesis. The relationship of expression level with clinicopathologic factors was also statistically studied.
Methods: Quantitative Polymerase Chain Reaction was performed on nasopharyngeal carcinoma and their paired normal tissues. Expression and sequence of these three genes were analysed.
Results: All three ribosomal protein genes showed no significant difference in transcript expressions and no association could be established with clinicopathologic factors studied. No nucleotide aberrancy was detected in the coding regions of these genes.
Conclusion: There is no early evidence to substantiate possible involvement of RPS26, RPS27, and RPL32 genes in NPC tumourigenesis.
5. Apoptotic and cytostatic actions of maslinic acid in colorectal cancer cells through possible IKK-β inhibition
Kai Xin OOI ; Menaga SUBRAMANIAM ; Yang Mooi LIM ; Lai Yen FONG ; Yang Mooi LIM ; Hoe Han GOH ; Soo Beng Alan KHOO
Asian Pacific Journal of Tropical Biomedicine 2021;11(3):122-131
Objective: To explore the anti-cancer activity of maslinic acid against colorectal cancer (CRC) cell lines and its possible mechanism. Methods: The inhibitory effect of maslinic acid was screened against five CRC cell lines (HT-29, HCT 116, SW480, SW48, and LS 174T) via 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Apoptosis and cell cycle analyses were carried out using annexin V-FITC/propidium iodide staining and propidium iodide staining, respectively and subjected to fluorescence-activated cell sorting analysis. Protein expression studies of inhibitor of κB kinase-β (IKK-β), checkpoint kinase 1 (Chk1) and cyclin D1 were conducted using the JESS system. Results: Maslinic acid exhibited growth inhibitory effect in a doseand time-dependent manner in HT-29 and HCT 116 cell lines. A more prominent apoptosis induced by maslinic acid was observed in HCT 116 cell line. However, in HT-29 cell line, maslinic acid induced cell cycle arrest by inhibiting the G1-S transition, which was accompanied by the downregulation of cyclin D1. The expression of unphosphorylated IKK-β protein was increased in both (HT-29 and HCT 116) cell lines after maslinic acid treatment. Conclusions: Maslinic acid inhibits the growth of HT-29 and HCT 116 cells in a different manner, induces cell cycle arrest in HT-29 cells and causes apoptosis in HCT 116 cells partially via NF-κB pathway inhibition.