Displaying publications 21 - 40 of 69 in total

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  1. Jabir RS, Naidu R, Annuar MA, Ho GF, Munisamy M, Stanslas J
    Pharmacogenomics, 2012 Dec;13(16):1979-88.
    PMID: 23215890 DOI: 10.2217/pgs.12.165
    Interindividual variability in drug response and the emergence of adverse drug effects are the main causes of treatment failure in cancer therapy. Functional membrane drug transporters play important roles in altering pharmacokinetic profile, resistance to treatment, toxicity and patient survival. Pharmacogenetic studies of these transporters are expected to provide new approaches for optimizing therapy. Taxanes are approved for the treatment of various cancers. Circulating taxanes are taken up by SLCO1B3 into hepatocytes. The CYP450 enzymes CYP3A4, CYP3A5 and CYP2C8 are responsible for the conversion of taxanes into their metabolites. Ultimately, ABCB1 and ABCC2 will dispose the metabolites into bile canaliculi. Polymorphisms of genes encoding for proteins involved in the transport and clearance of taxanes reduce excretion of the drugs, leading to development of toxicity in patients. This review addresses current knowledge on genetic variations of transporters affecting taxanes pharmacokinetics and toxicity, and provides insights into future direction for personalized medicine.
  2. Khan SU, Ahemad N, Chuah LH, Naidu R, Htar TT
    J Biomol Struct Dyn, 2020 Nov 08.
    PMID: 33164654 DOI: 10.1080/07391102.2020.1844059
    G protein-coupled receptors (GPCRs) belong to the largest family of protein targets comprising over 800 members in which at least 500 members are the therapeutic targets. Among the GPCRs, G protein-coupled estrogen receptor-1 (GPER-1) has shown to have the ability in estrogen signaling. As GPER-1 plays a critical role in several physiological responses, GPER-1 has been considered as a potential therapeutic target to treat estrogen-based cancers and other non-communicable diseases. However, the progress in the understanding of GPER-1 structure and function is relatively slow due to the availability of a only a few selective GPER-1 modulators. As with many GPCRs, the X-ray crystal structure of GPER-1 is yet to be resolved and thus has led the researchers to search for new GPER-1 modulators using homology models of GPER-1. In this review, we aim to summarize various approaches used in the generation of GPER-1 homology model and their applications that have resulted in new GPER-1 ligands.
  3. Khan SU, Ahemad N, Chuah LH, Naidu R, Htar TT
    J Biomol Struct Dyn, 2020 Oct 15.
    PMID: 33054574 DOI: 10.1080/07391102.2020.1830853
    Cancer ranks in second place among the cause of death worldwide. Cancer progress in multiple stages of carcinogenesis and metastasis programs through complex pathways. Sex hormones and their receptors are the major factors in promoting cancer progression. Among them, G protein-coupled estrogen receptor-1 (GPER) has shown to mediate cellular signaling pathways and cancer cell proliferation. However, the lack of GPER protein structure limited the search for new modulators. In this study, we curated an extensive database of natural products to discover new potential GPER modulators. We used a combination of virtual screening techniques to generate a homology model of GPER and subsequently used that for the screening of 30,926 natural products from a public database to identify potential active modulators of GPER. The best hits were further screened through the ADMET filter and confirmed by docking analysis. Moreover, molecular dynamics simulations of best hits were also carried out to assess the stability of the ligand-GPER complex. This study predicted several potential GPER modulators with novel scaffolds that could be further investigated and used as the core for the development of novel GPER modulators.Communicated by Ramaswamy H. Sarma.
  4. Kok YY, Chu WL, Phang SM, Mohamed SM, Naidu R, Lai PJ, et al.
    J Zhejiang Univ Sci B, 2011 May;12(5):335-45.
    PMID: 21528487 DOI: 10.1631/jzus.B1000336
    This study aimed to assess the inhibitory activities of methanol extracts from the microalgae Ankistrodesmus convolutus, Synechococcus elongatus, and Spirulina platensis against Epstein-Barr virus (EBV) in three Burkitt's lymphoma (BL) cell lines, namely Akata, B95-8, and P3HR-1. The antiviral activity was assessed by quantifying the cell-free EBV DNA using real-time polymerase chain reaction (PCR) technique. The methanol extracts from Ankistrodesmus convolutus and Synechococcus elongatus displayed low cytotoxicity and potent effect in reducing cell-free EBV DNA (EC(50)<0.01 µg/ml) with a high therapeutic index (>28000). After fractionation by column chromatography, the fraction from Synechococcus elongatus (SEF1) reduced the cell-free EBV DNA most effectively (EC(50)=2.9 µg/ml, therapeutic index>69). Upon further fractionation by high performance liquid chromatography (HPLC), the sub-fraction SEF1'a was most active in reducing the cell-free EBV DNA (EC(50)=1.38 µg/ml, therapeutic index>14.5). This study suggests that microalgae could be a potential source of antiviral compounds that can be used against EBV.
  5. Lee YQ, Rajadurai P, Abas F, Othman I, Naidu R
    Front Mol Biosci, 2021;8:645856.
    PMID: 33996900 DOI: 10.3389/fmolb.2021.645856
    Curcumin analogs with excellent biological properties have been synthesized to address and overcome the poor pharmacokinetic profiles of curcumin. This study aims to investigate the cytotoxicity, anti-proliferative, and apoptosis-inducing ability of curcumin analog, MS13 on human glioblastoma U-87 MG, and neuroblastoma SH-SY5Y cells, and to examine the global proteome changes in these cells following treatment. Our current findings showed that MS13 induced potent cytotoxicity and anti-proliferative effects on both cells. Increased caspase-3 activity and decreased bcl-2 concentration upon treatment indicate that MS13 induces apoptosis in these cells in a dose- and time-dependent manner. The label-free shotgun proteomic analysis has defined the protein profiles in both glioblastoma and neuroblastoma cells, whereby a total of nine common DEPs, inclusive of glyceraldehyde 3-phosphate dehydrogenase (GAPDH), alpha-enolase (ENO1), heat shock protein HSP 90-alpha (HSP90AA1), Heat shock protein HSP 90-beta (HSP90AB1), Eukaryotic translation initiation factor 5A-1 (EFI5A), heterogenous nuclear ribonucleoprotein K (HNRNPK), tubulin beta chain (TUBB), histone H2AX (H2AFX), and Protein SET were identified. Pathway analysis further elucidated that MS13 may induce its anti-tumor effects in both cells via the common enriched pathways, "Glycolysis" and "Post-translational protein modification." Conclusively, MS13 demonstrates an anti-cancer effect that may indicate its potential use in the management of brain malignancies.
  6. Lim TM, Naidu RR
    Med J Malaysia, 2001 Jun;56(2):240-2.
    PMID: 11771087
    This is a retrospective study of the annual mortality that occurred in the Department of Surgery, Alor Setar Hospital, for the years 1995 to 1997. This study looks at the number of admissions to the surgical wards and categorizes the causes of death. The annual mortality rates were 2.60, 2.89 and 3.25 per hundred admissions for the year 1995, 1996 and 1997 respectively. Head injury was the leading cause of death whilst sepsis and advanced malignancies second and third commonest causes. We hope that with the publication of these figures, we can initiate more studies to analyse similar local data.
  7. Naidu R, Har YC, Taib NA
    Onkologie, 2011;34(11):592-7.
    PMID: 22104155 DOI: 10.1159/000334060
    The present study aimed to evaluate the association between the E-Selectin Ser128Arg polymorphism and breast cancer risk and clinicopathological characteristics of the patients.
  8. Naidu R, Har YC, Taib NA
    APMIS, 2011 Jul;119(7):460-7.
    PMID: 21635553 DOI: 10.1111/j.1600-0463.2011.02753.x
    In the present study, we evaluated the association between the TP53BP1 Glu353Asp and T-885G polymorphisms and breast cancer risk as well as with the clinicopathological characteristics of the patients. Genotyping of these polymorphisms was performed on 387 breast cancer patients and 252 normal and healthy women who had no history of any malignancy using PCR-RFLP method in a hospital-based Malaysian population. Breast cancer risk was not observed among women who were heterozygous (OR(adj) = 0.887; 95% CI, 0.632-1.245) or homozygous (OR(adj) = 1.083; 95% CI, 0.595-1.969) for Asp allele, and those carriers of Asp allele (OR(adj) = 0.979; 95% CI, 0.771-1.243). Similarly, women who were TG heterozygotes (OR(adj) = 1.181; 95% CI, 0.842-1.658) or GG homozygotes (OR(adj) = 1.362; 95% CI, 0.746-2.486) and carriers of G allele (OR(adj) = 1.147; 95% CI, 0.903-1.458) were not associated with increased risk of breast cancer. Asp allele genotype was significantly associated with ER negativity (p = 0.0015) and poorly differentiated tumours (p = 0.008), but G allele genotype was not associated with the clinicopathological characteristics. In conclusion, Glu353Asp and T-885G polymorphic variants might not have an influence on breast cancer risk, thus might not be potential candidates for cancer susceptibility. Glu353Asp variant might be associated with tumour aggressiveness as defined by its association with ER negativity and poorly differentiated tumours.
  9. Naidu R, Har YC, Taib NA
    Pathol. Int., 2010 Sep;60(9):614-20.
    PMID: 20712647 DOI: 10.1111/j.1440-1827.2010.02568.x
    The aim of the present study was to evaluate the association between the Glyoxalase I (GLOI) Ala111Glu polymorphism and breast cancer risk among the major Malaysian ethnic groups, the Malays, Chinese and Indians, as well as clinico-pathological characteristics of these patients. Genotyping of GLOI gene was performed on blood samples obtained from 387 patients and 252 normal healthy women who had no history of any malignancy using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. The genotype and allele frequencies of GLOI polymorphism were not significantly different between the patients and normal individuals among the Malays (P= 0.721, 0.402), Chinese (P= 0.208, 0.079) and Indians (P= 0.612, 0.349), respectively. The Malay, Chinese and Indian women who were Glu/Glu homozygotes (P= 0.419, 0.093, 0.367), Ala/Glu heterozygotes (P= 0.648, 0.182, 0.402) and carriers of Glu allele (P= 0.402, 0.079, 0.349), respectively, were not associated with breast cancer risk. The Glu allele genotype was significantly associated with absence of progesterone receptor (P= 0.036). Thus, the polymorphic variant of the GLOI gene might not be a useful genetic marker to identify Malaysian Malay, Chinese or Indian women who could be at greater risk of developing breast cancer.

    Study site: Universiti Malaya Medical Centre (UMMC)
  10. Naidu R, Har YC, Taib NA
    Neoplasma, 2009;56(5):441-7.
    PMID: 19580347
    The C1772T, G1790A and C111A polymorphisms of Hypoxia-inducible factor-1alpha (HIF-1alpha) gene were analyzed in a hospital-based Malaysian population using PCR-RFLP method. Genomic DNA was extracted from the blood samples collected from 410 breast cancer patients and 275 normal and healthy women. We investigated the association between HIF-1alpha polymorphisms and breast cancer risk, and clinico-pathological parameters in the population. The genotype and allele frequencies of C1772T (P=0.0093 vs P=0.0024) polymorphism were significantly different between the breast cancer cases and normal subjects but similar association was not observed for G1790A (P>0.05) and C111A (P>0.05) polymorphisms, respectively. Women who were CT heterozygotes (OR=1.51; 95% CI, 1.01-2.25), TT homozygotes (OR=4.03; 95% CI, 1.09-17.60) and carriers of T allele genotype (OR=1.65; 95% CI, 1.13-2.43) were significantly associated with increased risk of breast cancer. Significant relationship was observed also between T allele and breast cancer risk (OR=1.69; 95% CI, 1.20-2.40). Clinico-pathological analysis showed that 1772T allele genotype was significantly associated with nodal metastases (P=0.0478) but independent of ER status, tumor grade and patients' age (P>0.05). Our observations suggest that the polymorphic allele of C1772T may be associated with increased risk of developing breast cancer, and presence of 1772T allele may be a useful genetic marker for tumor prognosis.
  11. Naidu R, Har YC, Taib NA
    Oncol Res, 2009;18(2-3):65-71.
    PMID: 20066896
    The genotype analysis of the Gly and Arg allele at codon 388 of fibroblast growth factor receptor-4 (FGFR4) gene was evaluated using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method in a hospital-based Malaysian population. Peripheral blood samples were collected from 387 breast cancer patients and 252 normal and healthy women who had no history of any malignancy. The aim of the present study was to evaluate the association between the FGFR4 Gly388Arg polymorphism and breast cancer risk as well as clinicopathological parameters of the patients. The Gly/Gly, Gly/Arg, Arg/Arg, and Arg allele genotypes were detected in 46.3%, 44.4%, 9.3%, and 53.7% of breast cancer cases, respectively. The distribution of genotype (p = 0.204) and allele (p = 0.086) frequencies of FGFR4 polymorphism were not significantly different between the breast cancer cases and normal individuals. Women who were Arg/ Arg homozygotes (OR = 1.714, 95% CI 0.896-3.278), Gly/Arg heterozygotes (OR = 1.205, 95% CI 0.863-1.683), carriers of Arg allele genotype (OR = 1.269, 95% CI 0.921-1.750), or Arg allele (OR = 1.246, 95% CI 0.970-1.602) were not associated with breast cancer risk. The Arg allele genotype was significantly associated with lymph node metastases (p = 0.001) but not with other clinicopathological parameters. Our findings suggest that the polymorphic variant at codon 388 of FGFR4 gene does not confer increased risk to breast cancer development but it may be a potential genetic marker for tumor prognosis.
  12. Naidu R, Yip CH, Taib NA
    Neoplasma, 2008;55(2):87-95.
    PMID: 18237245
    The HER2 codon Ile655Val and Cyclin D1 (CCND1) G870A polymorphisms were analyzed in a hospital-based Malaysian population using PCR-RFLP method. Peripheral blood samples were collected from 230 breast cancer patients, and 200 normal and healthy women who had no history of breast disease or breast cancer. We evaluated the association between HER2 or CCND1 polymorphisms and breast cancer risk, and clinico-pathological parameters in the population. The genotype and allele frequencies of HER2 (P=0.163 vs P=0.0622) and CCND1 (P=0.377 vs P=0.284) polymorphisms were not significantly different between the breast cancer cases and normal subjects, respectively. Women who were Ile/Val heterozygotes (OR=1.48; 95% CI, 0.91-2.43), Val/Val homozygotes (OR=1.93; 95% CI, 0.51-7.77) and carriers of Val allele genotype (OR=1.53; 95% CI, 0.95-2.45) were not significantly associated with increased breast cancer risk. Similarly, women who were homozygous (OR=1.34; 95% CI, 0.77-2.34) or heterozygous (OR=0.98; 95% CI, 0.60-1.60) for A allele, or carriers of A allele genotype (OR=1.10; 95% CI, 0.70-1.73) were not associated with breast cancer risk. Analysis on clinico-pathological parameters showed that Val allele genotype was significantly correlated with nodal metastases but A allele genotype was not associated with any of the variables. Our findings suggest that the polymorphic alleles of HER2 and CCND1 may not play an important role as genetic markers for breast cancer risk, but presence of Val allele may be useful for tumor prognosis.
  13. Naidu R, Har YC, Taib NA
    J Exp Clin Cancer Res, 2007 Mar;26(1):133-40.
    PMID: 17550142
    The p27 V109G polymorphism was investigated using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method in a hospital-based Malaysian population. Peripheral blood samples were collected from 230 breast cancer patients and 200 normal and healthy women who had no history of breast disease or breast cancer. We evaluated the association between the p27 polymorphism and breast cancer risk, and clinico-pathological parameters in the population. The distribution of genotype and allele frequencies of p27 V109G polymorphism were not significantly different between the breast cancer cases and normal subjects (P=0.376). Women who were homozygous (OR=1.73; 95% CI, 0.62-4.92) or heterozygous (OR=1.26; 95% CI, 0.75-2.12) for G allele, or carriers of G allele genotype (OR=1.34; 95%, 0.83-2.16) or G allele (OR=1.36; 95% CI, 0.90-2.05) were not associated with breast cancer risk. No significant correlation was noted between G allele genotype and breast cancer risk among patients under 50 (OR=1.28; 95% CI, 0.62-2.66) or 50 years and older (OR=1.38; 95% CI, 0.71-2.66) at diagnosis. The G allele genotype was significantly associated with lymph node metastases but independent of ER status and histological grade. In conclusion, the polymorphic variant at codon 109 of p27 gene may not be a marker for determining patients' risk of developing breast cancer but it may be a potential genetic marker for poor prognosis, thereby a marker for tumor prognosis.
  14. Naidu R, Yadav M, Nair S, Kutty MK
    Br. J. Cancer, 1998 Nov;78(10):1385-90.
    PMID: 9823984
    Expression of c-erbB3 protein was investigated in 104 primary breast carcinomas comprising nine comedo ductal carcinoma in situ (DCIS), 91 invasive ductal carcinomas and four invasive lobular carcinomas using two monoclonal antibodies, RTJ1 and RTJ2. Of the 91 invasive ductal carcinomas, seven contained the comedo DCIS component adjacent to the invasive component. An immunohistochemical technique was used to evaluate the association between expression of c-erbB3 and clinical parameters and tumour markers such as epidermal growth factor receptor (EGFR), c-erbB2, cathepsin-D and p53 in archival formalin-fixed paraffin-embedded tumour tissues. Our results indicated that RTJ1 and RTJ2 gave identical staining patterns and concordant results. It was found that the overexpression of c-erbB3 protein was observed in 67% (6/9) of comedo DCIS, 52% (44/84) of invasive ductal carcinomas, 71% (5/7) of carcinomas containing both the in situ and invasive lesions and 25% (1/4) of invasive lobular carcinomas. A significant relationship (P < 0.05) was observed between strong immunoreactivity of c-erbB3 protein and histological grade, EGFR and cathepsin-D, but not with expression of c-erbB2, p53, oestrogen receptor status, lymph node metastases or age of patient. However, we noted that a high percentage of oestrogen receptor-negative tumours (59%), lymph node-positive tumours (63%) and c-erbB2 (63%) were strongly positive for c-erbB3 protein. We have also documented that a high percentage of EGFR (67%), c-erbB2 (67%), p53 (75%) and cathepsin-D-positive DCIS (60%) were strongly positive for c-erbB3. These observations suggest that overexpression of c-erbB3 protein could play an important role in tumour progression from non-invasive to invasive and, also, that it may have the potential to be used as a marker for poor prognosis of breast cancer.
  15. Naidu R, Yadav M, Nair S, Kutty KK
    Anticancer Res, 1998 Jan-Feb;18(1A):65-70.
    PMID: 9568057
    Expression of p53 protein was investigated by immunohistochemical techniques in archival cases of 134 primary breast carcinomas comprising 13 comedo ductal carcinoma in situ (DCIS), 105 invasive ductal carcinomas, 7 contained the comedo DCIS component adjacent to the invasive ductal component, 5 invasive lobular carcinomas, three colloid carcinomas and one medullary carcinoma. Overexpression of p53 gene product was studied to determine the association with clinico-pathological parameters and also its relationship to c-erbB2. Overexpression of p53 protein was observed in 31% (4/13) of comedo DCIS, 37% (39/105) of invasive ductal carcinomas, 57% (4/7) of carcinomas containing both the in situ and invasive lesions and all medullary carcinomas. A significant relationship (p < 0.05) was observed between strong immunoreactivity of p53 protein and absence of estrogen receptor, histological grade and c-erbB2 but not with lymph node metastases or age of patient. These observations suggest that overexpression of p53 protein may play an important role in tumor progression from noninvasive to invasive in some breast carcinomas and may have potential as an indicator for poorer prognosis.
  16. Naidu R, Wahab NA, Yadav MM, Kutty MK
    Oncol Rep, 2002 Mar-Apr;9(2):409-16.
    PMID: 11836618
    Overexpression and amplification of cyclin D1 were investigated by immunohistochemistry and differential polymerase chain reaction (dPCR) in 440 formalin-fixed primary breast carcinoma tissues. Overexpression of cyclin D1 was detected in 60% (263/440) and amplification of cyclin D1 was noted in 27% (119/440) of the primary breast carcinomas. Molecular analysis demonstrated that cyclin D1 was amplified in 30% (7/23) of the comedo DCIS, 22% (9/41) of the comedo DCIS and 32% (13/41) of the adjacent invasive ductal carcinomas, 30% (82/270) of the invasive ductal carcinomas, 27% (9/33) of the invasive lobular carcinomas, 19% (4/21) of the colloid carcinomas and 13% (2/15) of the medullary carcinomas. Cyclin D1 was amplified in 11% (2/19) of the invasive ductal carcinomas but not in the adjacent non-comedo DCIS lesions. Our observation showed that cyclin D1 was strongly positive in 61% (14/23) of the comedo subtype, 61% (11/18) of the non-comedo subtype, 59% (24/41) of the comedo DCIS and 63% (26/41) of the adjacent invasive ductal carcinomas, 53% (10/19) of the non-comedo DCIS and 58% (11/19) of the adjacent invasive lesions, 58% (157/270) of the invasive ductal carcinomas, 73% (24/33) of the invasive lobular carcinomas, 52% (11/21) of the colloid carcinomas and 27% (4/15) of the medullary carcinomas. A significant association was observed between in situ components and adjacent invasive lesions for cyclin D1 expression (p<0.05) and amplification (p<0.05). A significant relationship was noted between amplification of cyclin D1 and lymph node metastases (p<0.05) but not with histological grade (p>0.05), estrogen receptor status (p>0.05) and proliferation index (Ki-67 and PCNA) (p>0.05). However, overexpression of cyclin D1 was statistically associated with well differentiated tumors (p<0.05) and estrogen receptor positivity (p<0.05). No relationship was seen with nodal status (p>0.05) and proliferation index (Ki-67 and PCNA) (p>0.05). These observations suggest that tumors positive for cyclin D1 protein may have features of good prognosis but amplification of cyclin D1 gene could be an indicator of tumors with poor prognostic features. Although majority of the Malaysian patients belong to younger age group (<50 years old), amplification and expression of cyclin D1 was not statistically associated with patient age (p>0.05). These observations indicate that amplification and up-regulation of cyclin D1 may be independent of patient age. Moreover, overexpression and amplification of cyclin D1 in preinvasive, preinvasive and adjacent invasive lesions, and invasive carcinomas suggest that the gene may play an important role in early and late stages of breast carcinogenesis.
  17. Naidu R, Wahab NA, Yadav M, Kutty MK
    Int J Mol Med, 2002 Feb;9(2):189-96.
    PMID: 11786932
    Overexpression of c-myc protein and amplification of c-myc were investigated by immunohistochemistry and differential polymerase chain reaction (dPCR) in 440 formalin-fixed primary breast carcinoma tissues, respectively. Overexpression of c-myc was detected in 45% (199/440) and amplification of c-myc was observed in 25% (112/440) of the primary breast carcinomas. Immunolocalization of c-myc oncoprotein was demonstrated in 35% (8/23) of the comedo subtype, 17% (3/18) of the non-comedo subtype, 37% (15/41) of the comedo DCIS and 49% (20/41) of the adjacent invasive ductal carcinomas, 21% (4/19) of the non-comedo DCIS and 37% (7/19) of the adjacent invasive lesions, 49% (133/270) of the invasive ductal carcinomas, 33% (11/33) of the invasive lobular carcinomas, 29% (6/21) of the colloid carcinomas and 47% (7/15) of the medullary carcinomas. C-myc was amplified in 13% (3/23) of the comedo DCIS, 17% (7/41) of the comedo DCIS and 24% (10/41) of the adjacent invasive ductal carcinomas, 30% (82/270) of the invasive ductal carcinomas, 21% (7/33) of the invasive lobular carcinomas, 14% (3/21) of the colloid carcinomas and 24% (4/15) of the medullary carcinomas. Amplification of c-myc was noted in 16% (3/9) of the invasive ductal carcinomas but not in the adjacent non-comedo DCIS lesions. A significant association (P<0.05) was observed between in situ components and adjacent invasive lesions for c-myc expression and amplification. Overexpression of c-myc protein was significantly correlated with poorly differentiated (P<0.05) and high proliferation index (Ki-67) (P<0.05) tumors but not with lymph node metastases (P>0.05), patient age (P>0.05) and estrogen receptor status (P>0.05). Significant relationship was also noted between amplification of c-myc and absence of estrogen receptor (P<0.05), high histological grade (P<0.05) and high proliferation index (Ki-67) (P<0.05). No relationship was seen with nodal status (P>0.05) and patient age (P>0.05). Majority of the Malaysian female patients are from younger age group (<50 years old) but overexpression and amplification of c-myc was not statistically associated with patient age (P>0.05) indicating that these alterations may be independent events of patient age. The above observations suggest that overexpression and amplification of c-myc could play an important role in tumor progression from non-invasive to invasive and, also, it may have the potential as a marker of poor prognosis of breast cancer.
  18. Naidu R, Wahab NA, Yadav M, Kutty MK, Nair S
    Int J Mol Med, 2001 Aug;8(2):193-8.
    PMID: 11445874
    Amplification of int-2/FGF-3 gene was investigated by differential polymerase chain reaction (dPCR) in 440 archival primary breast carcinoma tissues. Of these, 23 were comedo ductal carcinoma in situ (DCIS), 18 were non-comedo DCIS, 41 were comedo DCIS with adjacent invasive ductal carcinomas, 19 were non-comedo DCIS with adjacent invasive ductal carcinomas, 270 were invasive ductal carcinomas, 33 were invasive lobular carcinomas, 21 were colloid carcinomas and 15 were medullary carcinomas. Int-2 was amplified in 22% (96/440) of the primary breast carcinomas. It was shown that int-2 was amplified in 13% (3/23) of the comedo DCIS, 17% (7/41) of the comedo DCIS and 29% (12/41) of the adjacent invasive ductal carcinomas, 26% (71/270) of the invasive ductal carcinomas, 18% (6/33) of the invasive lobular carcinomas, 10% (2/21) of the colloid carcinomas and 13% (2/15) of the medullary carcinomas. In contrast, int-2 was not amplified in non-comedo DCIS and invasive ductal carcinomas with adjacent non-comedo DCIS lesions. A significant association was observed between int-2 amplification in the in situ components and adjacent invasive lesion (P<0.05). All tumors with int-2 amplification in the in situ lesions (7/7) also demonstrated same degree of amplification in the adjacent invasive components. However, 9% (5/53) of the tumors with no amplified int-2 gene in the in situ components showed int-2 amplification in the adjacent invasive lesions. A significant relationship was noted between amplification of int-2 and lymph node metastases (P<0.05) and poorly differentiated tumors (P<0.05) but not with estrogen receptor status (P>0.05) and proliferation index (Ki-67 and PCNA) (P>0.05). In Malaysia, majority of the patients belong to younger age group (<50 years old) but a comparison of the age groups showed that the amplification of int-2 was not statistically associated with patient age (P>0.05). These observations indicate that amplification of int-2 tends to strengthen the view that int-2 may have the potential to be an indicator of poor prognosis regardless of the age of the patient. Moreover, the presence of int-2 amplification in preinvasive, preinvasive and adjacent invasive lesions, and invasive carcinomas suggest that int-2 could be a marker of genetic instability occurring in early and late stages of tumor development.
  19. Naidu R, Har YC, Taib NA
    Scand J Clin Lab Invest, 2011 Oct;71(6):500-6.
    PMID: 21745146 DOI: 10.3109/00365513.2011.590223
    The purpose of this study was to investigate the association between the peptidyl-propyl-cis/trans isomerase 1 (PIN1) -842(G > C) and -667(T > C) polymorphic variants and breast cancer risk among Malaysian ethnic groups namely the Malays, Chinese and Indians, as well as clinico-pathological characteristics of the patients.
  20. Naidu R, Yip CH, Taib NA
    Med Oncol, 2012 Jun;29(2):411-7.
    PMID: 21301999 DOI: 10.1007/s12032-011-9837-8
    The purpose of the present study was to evaluate the association between TCF7L2 rs12255372(G/T) or rs7903146(C/T) polymorphism and breast cancer risk, and clinico-pathologic characteristics of the patients. Genotyping of these polymorphisms was performed on 387 breast cancer patients and 252 normal and healthy women who had no history of any malignancy using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method in a hospital-based Malaysian population. The allele (P = 0.033) frequency of rs7903146 (T) polymorphism was significantly higher in the cancer patients than normal individuals. No significant association was demonstrated between CT (OR(adj) = 1.386; 95% CI, 0.985-1.949) or TT (OR(adj) = 1.579; 95% CI, 0.869-2.870) genotype and breast cancer risk. However, women who were carriers of T allele (OR(adj) = 1.316; 95% CI, 1.022-1.695) or T allele genotype (OR(adj) = 1.419; 95% CI, 1.027-1.960) showed significant increased risk of breast cancer. Women who were GT heterozygotes (OR(adj) = 1.329; 95% CI, 0.948-1.862) or TT homozygotes (OR(adj) = 1.574; 95% CI, 0.829-2.987), and carriers of T allele genotype (OR(adj) = 1.365; 95% CI, 0.989-1.883) or T allele (OR(adj) = 1.284; 95% CI, 0.995-1.657) were not associated with breast cancer risk. The rs7903146(T) allele genotype was significantly associated with nodal involvement (P = 0.003) but rs12255372 (T) allele genotype was not associated with the clinico-pathologic characteristics. In conclusion, our findings suggest that rs7903146 (T) variant may elevate the risk of breast cancer, thus could be a potential candidate for breast cancer susceptibility. The variant may also increase the metastatic potential of the tumor.
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