Real-time quantitative PCR analysis of amplified DNA on chromosomes 4p15.2 and 6q23-24 from formalin-fixed, paraffin-embedded breast cancer tissues.

This study was performed to detect amplification of DNA sequences on chromosomes 4p15.2 and 6q23-24, obtained from formalin-fixed, paraffin-embedded, breast-cancer tissues. The prognostic relevance of the amplification was also demonstrated. DNA from formalin-fixed, paraffin-embedded tumor and corresponding normal tissues of 53 patients with breast cancer was extracted and amplified by real-time quantitative PCR technique. Amplification of the DNA sequences on chromosomes 4p15.2 and 6q23-24 was detected in 23 (43%) and 32 (60%) cases, respectively. Thirty-six (68%) cases showed amplification on both or one of the chromosomes. These frequencies are similar to that obtained from fresh samples in our previous study. In addition, amplification of the DNA on chromosomes 4p15.2 and / or 6q23-24 was predominantly observed in tumors with invasive ductal carcinoma. The findings in this study demonstrate that DNA extracted from formalin-fixed, paraffin-embedded breast tumors can be used to determine amplification of DNA sequences on selective chromosomal regions. We also suggest that the amplified DNA on chromosomal regions 4p15.2 and 6q23-24 might be involved in the development and progression of breast cancer.

Identification of genetic alterations in thai breast cancer patients by arbitrarily primed polymerase chain reaction.

Breast cancer is the most common cancer among women worldwide. Genetic alterations prevalent in breast cancer are still being elucidated. In this report, changes in 30 breast cancer tissues, in comparison with normal tissues from Thai patients, were analyzed by arbitrarily primed polymerase chain reaction (AP-PCR). Genetic instability was detected by DNA fingerprinting obtained with 13 of 60 random primers. Of these, at least one amplification band, the incidence ranging from 27 to 80%, was observed in DNA amplified with 8 primers, whereas a band loss was exhibited with from 6 primers, the incidences ranging from 23 to 40%. Likewise, an amplification band amplified from primer D15 was observed in 80% of this patient group and a band loss produced from primer B12 presented in 40% of all cases. These results showed that AP-PCR is effective for the detection of genetic alterations in breast cancer tissues.

Genetic instability in cervical cancer detected by arbitrarily primed polymerase chain reaction.

The genetic instability in 54 Thai cervical cancer tissues were analyzed by Arbitrarily Primed Polymerase Chain Reaction (AP-PCR). The band alterations produced from 54 arbitrary primers were compared between the DNA finger printing from the patients and their corresponding normal cervical tissues. Results revealed 7 arbitrary primers provided DNA alteration patterns. Of these, an allelic loss in tumor DNA was found in DNA fingerprinting obtained from primers F-2 (64.8%), F-11 (68.5%), U-8 (51.9%), AE-3 (75.9%), AE-11 (53.7%), respectively. Moreover, DNA amplification was exhibited in patterns with primers B-12 (42.6%), J-16 (24.1%) and U-8 (70.4%). When genetic instability was investigated for associations with clinicopathological features, only the DNA amplified fragment with primer U-8 was significantly associated with stage II (P=0.030). Likewise, allelic loss amplified from arbitrary primer AE-3 showed significantly associate with age lower than 50 years old (P=0.003). Our findings suggest that the DNA alteration fragments produced from arbitrary primers of U-8 and AE-11 might be relevant to the pathogenesis of cervical cancer in Thai patients.

HLa-class II (DRB & DQB1) in Thai sudden unexplained death syndrome (Thai SUDS) families (Lai-Tai families).

Thai Sudden Unexplained Death Syndrome (Thai SUDS), or Lai-Tai, is a major health problem among rural residents of northeastern Thailand. The cause has been identified as a genetic disease. SUDS, a disorder found in Southeast Asia, is characterized by an abnormal electrocardiogram with ST-segment elevation in leads V1-V3, identical to that seen in Brugada Syndrome (Brugada Sign, BS) and sudden death due to ventricular fibrillation and cardiac arrest (represents an arrhythmogenic marker that identifies high-risk for SUDS). SUDS victims have a sleeping disorder (narcolepsy). The HLA-DR locus is tightly associated with narcoleptic Japanese patients and HLA-DR2, DQ haplotypes were also found in Oriental narcoleptic patients. These circumstances prompted us to study the association between the disease and HLA Class II by HLA DNA typing using a PCR-SSO method, with five Thai SUDS families (18 BS-positive subjects as the cases, and 27 BS-negatives as the controls). We found that the HLA-DRB1 *12021 allele was significantly increased in BS-positive subjects (p = 0.02; OR = 4.5), the same as the HLA-DRB1*12021-DQB1 *0301/09 haplotype (p = 0.01; OR = 7.95). Our data suggests that the HLA-DRB1* 12021 allele associated with BS and the HLA-DRB1*12021-DQB1 *0301/09 is a haplotype susceptible to arrhythmogenic markers that can identify a high risk for SUDS.

Cancer: determinants and progression.

Cancer is the combination of uncontrolled cellular proliferation and immortality. It is a multi-step disease with a multi-factorial etiology. The determinants of cancer are many and varied including genetic predisposition, environmental influences, infectious agents, nutritional factors, hormonal and reproductive factors, radiation etc. However, the extent of the genetic involvement and their interaction with environment in tumorigenesis is still elusive. The six essential alterations in cell are proposed which determines the transition from normal cell to malignant. It includes--self-sufficiency in growth signals, insensitivity to growth-inhibitory (antigrowth) signals, evasion of programmed cell death (apoptosis), limitless replicative potential, sustained angiogenesis, and tissue invasion and metastasis. Nevertheless, the last two decades have seen rapid improvements in understanding the complex molecular mechanisms underlying tumorigenesis, yet the quest for unraveling the mystery is not over. Further study in this area is indispensable that could hold the promise of increasing our understanding of cancer etiology and possible preventive strategy.

Methylenetetrahydrofolate reductase (MTHFR) polymorphism (C677T) in relation to homocysteine concentration in overweight and obese Thais.

We analyzed the association between MTHFR (C677T) gene polymorphism with serum concentrations of homocysteine, folate, and vitamin B12 in 37 male and 112 female overweight/ obese Thai volunteers (BMI > or = 25.00 kg/m2), and compared them with 23 male and 90 female control subjects (BMI = 18.5-24.99 kg/m2). Statistically significant higher levels of serum homocysteine were found in the overweight/obese subjects than the control subjects (p < 0.05). Serum folic acid levels in the overweight/obese subjects were significantly lower than the control subjects (p < 0.05). When the data were grouped according to homocysteine concentration and MTHFR gene polymorphism, there were significantly higher homocysteine concentrations in the overweight/obese subjects than the control subjects in wild type gene polymorphism (CC) in the hyperhomocysteine group (homocysteine >10.0 mmol/l) (p < 0.05), but in genotype polymorphism (CC, CT, TT) there were lower folic acid and vitamin B12 concentrations in the overweight/obese subjects than in the control subjects. In the hyperhomocysteine groups, there was no significant difference in the frequencies of MTHFR (C677T) gene polymorphism between the overweight/obese subjects and the control subjects. Folic acid and gene polymorphism were found to be significantly related to the overweight/ obese and control groups in logistic regression analysis (p < 0.05). The results support the supposition that folic acid is more important than vitamin B12.