p15(Ink4b) Loss of Expression by Promoter Hypermethylation Adds to Leukemogenesis and Confers a Poor Prognosis in Acute Promyelocytic Leukemia Patients / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: The p15(Ink4b) gene exerts its influence as an inhibitor of cyclin-dependent kinases and is frequently associated with hematological malignancies. Inactivation of this gene through DNA methylation has been found to be the most prevalent epigenetic alteration reported, with a high frequency in all French-American-British subtypes of acute myeloid leukemias, including acute promyelocytic leukemia (APL). In this study,we investigated the prognostic significance of p15 gene promoter hypermethylation and its expression in APL patients of Kashmir (North India). MATERIALS AND METHODS: p15 gene promoter hypermethylation was conducted by methylation-specific polymerase chain reaction, while its subsequent expression analysis was carried out by semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR). RESULTS: Of the 37 patients, 16 (43.2%) were found to have methylated p15 genes. Of these 16 cases, seven (43.8%) were methylated partially and nine (56.2%) were found to have complete methylation. Moreover, nine of the 37 patients (24.3%) who presented with leukocytosis at their baseline had complete p15 gene methylation as well (p < 0.05). Semiquantitative RT-PCR showed a complete loss of p15 expression in nine patients with complete methylation coupled with leukocytosis (p=0.031), while seven patients with partial methylation showed decreased p15 expression. Six patients relapsed during the maintenance phase of treatment and were found to have a completely methylated p15 gene and no p15 mRNA. CONCLUSION: Complete methylation and loss of p15 gene expression causes susceptibility to relapse and decreased survival in APL patients. Thus, p15 promoter hypermethylation is a prospective prognostic indicator and a reliable clinical aid in assessment of patients with APL.

p15(Ink4b) Loss of Expression by Promoter Hypermethylation Adds to Leukemogenesis and Confers a Poor Prognosis in Acute Promyelocytic Leukemia Patients / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: The p15(Ink4b) gene exerts its influence as an inhibitor of cyclin-dependent kinases and is frequently associated with hematological malignancies. Inactivation of this gene through DNA methylation has been found to be the most prevalent epigenetic alteration reported, with a high frequency in all French-American-British subtypes of acute myeloid leukemias, including acute promyelocytic leukemia (APL). In this study,we investigated the prognostic significance of p15 gene promoter hypermethylation and its expression in APL patients of Kashmir (North India). MATERIALS AND METHODS: p15 gene promoter hypermethylation was conducted by methylation-specific polymerase chain reaction, while its subsequent expression analysis was carried out by semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR). RESULTS: Of the 37 patients, 16 (43.2%) were found to have methylated p15 genes. Of these 16 cases, seven (43.8%) were methylated partially and nine (56.2%) were found to have complete methylation. Moreover, nine of the 37 patients (24.3%) who presented with leukocytosis at their baseline had complete p15 gene methylation as well (p < 0.05). Semiquantitative RT-PCR showed a complete loss of p15 expression in nine patients with complete methylation coupled with leukocytosis (p=0.031), while seven patients with partial methylation showed decreased p15 expression. Six patients relapsed during the maintenance phase of treatment and were found to have a completely methylated p15 gene and no p15 mRNA. CONCLUSION: Complete methylation and loss of p15 gene expression causes susceptibility to relapse and decreased survival in APL patients. Thus, p15 promoter hypermethylation is a prospective prognostic indicator and a reliable clinical aid in assessment of patients with APL.

Frequency and pattern of cytogenetic alterations in primary amenorrhea cases of Kashmir, North India

Background: Primary amenorrhea [PA] is proposed to have multiple etiological factors that include genetic factors, intrauterine malformations, endocrine dysfunction and environmental factors, as revealed by previous studies pertaining to amenorrhea. However, among the various proposed etiologies, genetic factors appear to be highly associated with PA as approximately 40% of PA cases have been found to have genetic causes

Aim of the study: The present study was proposed to establish the frequency and pattern of chromosomal abnormalities in PA cases of Kashmir

Subjects and methods: A total of 108 females within the age group of 14-33 years and having a history of amenorrhea were included in the study. Peripheral blood lymphocyte cultures were set for each subject according to standard protocol and chromosomal analysis was carried out on well spread metaphases by the help of Cytovision software Version 3.9

Results: The results of the present study reveal that the incidence of chromosomal abnormalities in PA cases of this region is almost similar with those of many reports around the world. However, we report two unique chromosomal alterations viz., 46, XX, dup2q[13] and 46,XX, t[2,5][p11.2;q34] that have not been found elsewhere in the literature

Conclusion: The results of the present study indicate that chromosomal analysis of females with PA, after the exclusion of nongenetic causes, should be essentially considered for the precise diagnosis and the development of more successful treatment. The study being the first of its kind in this part of the world forms the basis for further studies of the PA cases of this region. The precise molecular characterization of the unique breakpoint regions reported in our study can possibly help in the identification of new genes involved in primary amenorrhea

Cytogenetic diagnosis of Roberts SC phocomelia syndrome: first report from Kashmir

There are several syndromes in which specific mitotic chromosomal abnormalities can be seen, like premature centromere separation, premature [sister] chromatid separation, and somatic aneuploidies. Identifications of such specific cytogenetic findings can be the key factor that leads towards the diagnosis of syndromes like Roberts SC phocomelia. The case presented here as Roberts SC phocomelia syndrome was identified as a child with multiple congenital anomalies and dysmorphic features. Conventional cytogenetic analysis of the case revealed premature sister chromatid separation. The premature centromeric separation was also confirmed by C banding analysis of the child. It is the first and the only case of Roberts SC phocomelia diagnosed from this part of the world. The present case report emphasizes the importance of conventional cytogenetics in the diagnosis of such syndromes

Molecular gate keepers succumb to gene aberrations in colorectal cancer in Kashmiri population, revealing a high incidence area

Colorectal cancer [CRC] is one of the leading malignancies worldwide and has been reported to show geographical variation in its incidence, even within areas of ethnic homogeneity. The aim of this study was to identify p53 and K-ras gene mutations in CRC patients in a Kashmiri population, and to assess whether these mutations are linked with clinicopathological parameters. Paired tumor and normal tissue samples from a consecutive series of 53 patients undergoing resective surgery for CRC were prospectively studied for p53 and K-ras gene mutations by PCR/single strand conformation polymorphism [SSCP]. Less than half [45%, 19/42] of the patients presented mutations in the p53 gene. Twenty eight mutations were found in the p53 gene, which comprised of 23 substitutions [17 transitions + 6 transversions], and five insertions. The 23 substitutions constituted 18 missense mutations, two nonsense mutations, and three silent mutations. Of the 28 mutations [7.14%] observed in this study, 2 were not previously reported for CRC samples and were identified as novel p53 mutations. A few patients [22.64%, 12/53] presented with mutations in K-ras, constituting 13 missense mutations, out of which 11 were G-A transitions, one was a G-C transversion, and one a G-T transversion. More than half [61.5%] of the mutations occurred in codon 12 whereas a few [38.5%] occurred in codon 13. One tumor contained missense mutations in both codons. Comparison of the mutation profiles of our patients with those of other ethnic populations and regions reflected both differences and similarities, indicating co-exposure to a unique set of risk factors. Mutations of the p53 and K-ras genes are some of the most common genetic changes in the development of human CRC. The high frequency of p53 gene mutations implicates p53 as a predominant factor for CRC in the high-risk ethnic Kashmiri population