A clinicopathological exploration of Hedgehog signaling: implications in oral carcinogenesis.

INTRODUCTION: Hedgehog Signaling, a basic cancer stem cell pathway, plays a major role during the embryonic development, is known to play a quiescent role in adults. However, aberrant activation of Hedgehog signaling in adults is known to play a role in cancer development. Hence, the aim of the study was to identify the role of Hedgehog signaling pathway in the Oral cancers. MATERIALS AND METHODS: The expression of Hedgehog signaling pathway was evaluated in 124 patients through the quantitative real-time PCR. The association between the gene expression and clinico-pathological parameters were analyzed using the Pearson chi-square test and survival analysis was carried out using Kaplan-Meier analysis. RESULTS: SHH and GLI1 was found to be significantly associated with the Lymph Node Status and SUFU was significantly associated with the Age. SMO and SUFU were found to have a worse prognosis in oral cancer patients. According to our findings, IHH plays a critical role in the activation of the HH signaling pathway in oral cancer. CONCLUSION: These findings back up the use of the Hedgehog signaling pathway as a biomarker for early disease prediction in oral cancer, as well as its role in tumor aggressiveness and invasiveness.

An association of epidermal growth factor receptor mutation subtypes with prognostic prediction and site-specific recurrence in advanced stage lung cancer patients.

BACKGROUND: Concerning the different clinical behavior of epidermal growth factor receptor (EGFR) subtypes in advanced-stage lung cancer patients, the current study aimed to evaluate the clinical, pathological, and prognostic significance of EGFR mutation subtypes, and treatment response in patients with advanced-stage lung cancer. METHODS AND RESULTS: A retrospective study enrolled a total of 346 patients with advanced-stage lung cancer tested for EGFR mutation. EGFR mutation was analyzed by amplification refractory mutation system-polymerase chain reaction (ARMS-PCR). Statistical analysis was performed using SPSS version 20.0. EGFR mutation was evident in 38% of patients with the highest prevalence of exon 19 deletions. A higher incidence of 19-deletions and 20-insertions were observed in young patients, while a higher incidence of L858R was noted in old age patients. Patients with de-novo T790M failed to improve their OS by any of the treatment modalities. Patients with de-novo T790M mutation have a higher risk of developing lung, liver, and multiple site metastases while patients with L858R mutation have a higher risk of developing brain metastasis. Additionally, patients with 19 deletion mutation did not improve their OS after receiving conventional chemotherapy hence, they demonstrate better survival only after EGFR-TKIs. Multivariate survival analysis predicted chemotherapy as an independent predictor of OS. CONCLUSION: Besides clinicopathological and prognostic consequences of EGFR mutation and mutation subtypes, patients harboring TKI sensitive, or insensitive mutations reveal different secondary disease development and hence should be treated accordingly for better survival. Current findings may provide the basis for a better treatment strategy.

Identification of novel exonic variants contributing to hereditary breast and ovarian cancer in west Indian population.

Breast and ovarian cancers are the most common cancer types in females worldwide and in India. Patients with these cancers require an early diagnosis which is essential for better prognosis, treatment and improved patient survival. Recently, the utilization of next-generation sequencing (NGS)-based screening has accelerated molecular diagnosis of various cancers. In the present study, we performed whole-exome sequencing (WES) of 30 patients who had a first or second-degree relative with breast or ovarian cancer and are tested negative for BRCA1/2 or other high and moderate-risk genes reported for HBOC. WES data from patients were analyzed and variants were called using bcftools. Functional annotation of variants and variant prioritization was performed by Exomiser. The clinical significance of variants was determined as per ACMG classification using Varsome tool. The functional analysis of genes was determined by STRING analysis and disease association was determined by open target tool. We found novel variants and gene candidates having significant association with HBOC conditions. The genes identified by exomiser (phenotype score > 0.75) are associated with various biological processes such as DNA integrity maintenance, transcription regulation, cell cycle regulation, and apoptosis. Our findings provide novel and prevalent gene variants associated with the HBOC condition in the West Indian population which could be further studied for early diagnosis and better prognosis of HBOC.

Role of epithelial - Stromal interaction protein-1 expression in breast cancer.

BACKGROUND AND AIMS: Epithelial stromal interaction protein-1 (EPSTI-1) is originally identified as stromal-fibroblast - induced gene in breast cancer. It was found to be involved in promotion of EMT, breast cancer invasion, metastasis and anchorage-independent growth in vitro. Strong expression was observed in various tissues as well as higher expression was observed in invasive breast cancer compared to normal breast. EPSTI-1 expression was evaluated from 106 pre-therapeutic breast cancer patients. EPSTI-1 expression was correlated with known clinico-pathological parameters of breast cancer to explore its role in breast carcinogenesis. SUBJECTS AND METHODS: EPSTI-1 expression was analyzed from the collected synchronous tissues [tumors, Malignant Lymph nodes (LN) and adjacent normal tissues (ANT)] of breast carcinoma patients (N = 106). The statistical correlation was performed using SPSS 16.0. RESULTS: In this study EPSTI-1 was significantly higher in LN compared to tumors (P < 0.001), and in tumors compared to ANT (P < 0.01) which is also reflected in ROC curve analysis (P < 0.0001). Further the small tumor size, stage I, grade I and tumors without stromal involvement exhibited significant lower expression compared to their counter parts. CONCLUSION: EPSTI-1 may have significant role in epithelial stromal interaction and disease extension. Moreover, it may be responsible for aggressive tumor behavior and involved in metastatic process which needs to be validated in larger cohort.

Clinical significance of serum 25 hydroxyvitamin D in breast cancer: An Indian scenario.

Recent evidences suggest a protective mechanism of vitamin D signaling against breast cancer by the autocrine/paracrine manner and may modestly reduce the risk of breast cancer. Despite lots of sunshine, vitamin D deficiency is widespread in India. Moreover, there are limited studies from Indian population regarding circulatory 25(OH) D and breast cancer risk. Thus, the aim of the present study is to investigate circulatory 25(OH) D in relation to breast cancer risk and its association with various clinico-pathological parameters from Indian population. Total 297 subjects, comprising of 157 controls and 140 breast cancer patients were enrolled for the study. Circulatory 25(OH) D was analyzed by HPLC. Statistical analysis was carried out by SPSS software version 15. Further, subjects were categorized into severe, moderate, mild vitamin D deficiency and sufficiency. The prevalence of severe and moderate 25(OH) D deficiency was higher in breast cancer patients as compared to controls. Mean values of 25(OH) D were lower in breast cancer patients as compared to controls in mild, moderate and severe deficient groups (p = 0.07, p = 0.003 and p = 0.001). Moreover, 25(OH) D was significantly lower in postmenopausal breast cancer patients as compared to premenopausal breast cancer patients, particularly in severe deficient group. The levels of 25(OH) D were lower in ER and PR negative receptor status as compared to the positive receptor in severe deficient category (p = 0.06 and p = 0.09 respectively). Whereas, the mean values of 25(OH) D were lower in HER 2 negative receptor status as compared to positive receptor status in the moderate deficient category (p = 0.09). Further, severe deficient group showed significantly lower levels of 25(OH) Din TNBC as compared to luminal A subtype (p = 0.01). Thus, Results indicate that 25(OH) D deficiency might be associated with increased risk of breast cancer. Moreover, severe 25(OH) D deficiency is associated with aggressive behavior of breast cancer.

A Prognostic and Predictive Study of BCR-ABL Expression Based on Characterization of Fusion Transcripts.

BCR-ABL translocation is a key hallmark of chronic myeloid leukemia (CML). The chemistry involves transcription of a novel 8.5 kb mRNA with a b3a2 and/ or b2a2 junction. Though there is an improvement in survival using the TKIs, there are causes for the treatment failures. Thus, the study focuses on the causes underlying the failed response. This study comprises BCR-ABL expression in correlation with age, gender and transcript type and disease monitoring in follow-up samples. Eighty-seven chronic phase CML patients were enrolled in the study. Out of these 24 patients were followed further. Quantitative Real time PCR was performed to assess the BCR-ABL expression followed by gel electrophoresis of PCR products. The results were expressed as CN/µg RNA. The results obtained were correlated with SPSS 16.0 software. We found three different types of the expression that includes b2a2, b3a2 and co-expression (b2a2 + b3a2). Higher incidence of b2a2 with a relatively equal incidence of co-expression was observed. The BCR-ABL expression was higher in males, in young patients and in those exhibiting co-expression of the transcripts. Greater relapse was seen in females and in older patients. The patients with co-expression of transcripts exhibited the highest expression; however these patients showed the best treatment response suggest the co-expression is the favourable parameter for CML patients. The transcript type and BCR-ABL expression are well correlated and hence can be considered as a prognostic as well as the predictive indicator considering the BCR-ABL expression for CML patients.

Mutational Landscape for Indian Hereditary Breast and Ovarian Cancer Cohort Suggests Need for Identifying Population Specific Genes and Biomarkers for Screening.

BACKGROUND: Breast and ovarian cancers are the most prevalent cancers and one of the leading causes of death in Indian women. The healthcare burden of breast and ovarian cancers and the rise in mortality rate are worrying and stress the need for early detection and treatment. METHODS: We performed amplicon sequencing of 144 cases who had breast/ovarian cancer disease (total 137 cases are patients and seven are tested for BRCA1/2 carrier) Using our custom designed gene panel consisting of 14 genes, that are associated with high to moderate risk of breast and ovarian cancers. Variants were called using Torrent Variant Caller and were annotated using ThermoFisher's Ion Reporter software. Classification of variants and their clinical significance were identified by searching the variants against ClinVar database. RESULTS: From a total of 144 cases, we were able to detect 42 pathogenic mutations in [40/144] cases. Majority of pathogenic mutations (30/41) were detected in BRCA1 gene, while (7/41) pathogenic mutations were detected in BRCA2 gene, whereas, (2/41) pathogenic mutations were detected in TP53 gene and BRIP1, PALB2, and ATM genes respectively. So, BRCA genes contributed 88.09% of pathogenic mutations, whereas non-BRCA genes contributed 11.91% of pathogenic mutations. We were also able to detect 25 VUS which were predicted to be damaging by in silico prediction tools. CONCLUSION: Early detection of cancers in the Indian population can be done by genetic screening using customized multi-gene panels. Indications of our findings show that in the Indian population, apart from the common BRCA genes, there are other genes that are also responsible for the disease. High frequency mutations detected in the study and variants of uncertain significance predicted to be damaging by in silico pathogenicity prediction tools can be potential biomarkers of hereditary breast and ovarian cancer in Indian HBOC patients.

Computational analysis of high-risk SNPs in human CHK2 gene responsible for hereditary breast cancer: A functional and structural impact.

Nowadays CHK2 mutation is studied frequently in hereditary breast and ovarian cancer patients in addition to BRCA1/BRCA2. CHK2 is a tumor suppressor gene that encodes a serine/threonine kinase, also involved in pathways such as DNA repair, cell cycle regulation and apoptosis in response to DNA damage. CHK2 is a well-studied moderate penetrance gene that correlates with third high risk susceptibility gene with an increased risk for breast cancer. Hence before planning large population study, it is better to scrutinize putative functional SNPs of CHK2 using different computational tools. In this study, we have used various computational approaches to identify nsSNPs which are deleterious to the structure and/or function of CHK2 protein that might be causing this disease. Computational analysis was performed by different in silico tools including SIFT, Align GVGD, SNAP-2, PROVEAN, Poly-Phen-2, PANTHER, PhD-SNP, MUpro, iPTREE-STAB, Consurf, InterPro, NCBI Conserved Domain Search tool, ModPred, SPARKS-X, RAMPAGE, Verify-3D, FT Site, COACH and PyMol. Out of 78 nsSNP of human CHK2 gene, seven nsSNPs were predicted functionally most significant SNPs. Among these seven nsSNP, p.Arg160Gly, p.Gly210Arg and p.Ser415Phe are highly conserved residues with conservation score of 9 and three nsSNP were predicted to be involved in post translational modification. The p.Arg160Gly and p.Gly210Arg may interfere in phosphopeptide binding site on FHA conserved domain. The p.Ser415Phe may interfere in formation of activation loop of protein-kinase domain and might interfere in interactions of CHK2 with ligand. The study concludes that mutation of serine to phenylalanine at position 415 is a major mutation in native CHK2 protein which might contribute to its malfunction, ultimately causing disease. This is the first comprehensive study, where CHK2 gene variants are analyzed using in silico tools hence it will be of great help while considering large scale studies and also in developing precision medicines related to these polymorphisms in the era of personalized medicine.

Clinical significance of inflammatory mediators in the pathogenesis of oral cancer.

Oral cancer has become a grave problem in many parts of the globe with two.thirds of the cases occurring in developing countries. Chronic inflammation plays a prominent role in the development of oral cancer. The rationale for molecular targeted prevention of oral cancer is promising. Therefore, there are continued improvements to our understanding of the molecular connections between inflammation and oral cancer. The inflammatory mediators including nuclear factor kappa B, vascular endothelial growth factor, inflammatory cytokines, prostaglandin pathways, p53, reactive oxygen and nitrogen species, and microRNAs are major key players in the pathogenesis of oral cancer. Currently, visual cytology.based techniques and biopsy are used to detect dysplasia and early stage of oral squamous cell carcinoma. These approaches are limited in their ability to judge the severities of oral lesions and are useful only after the appearance of visual changes. Thus, traditional cytological and biopsy assays combined with testing of inflammatory biomarkers would be beneficial for the efficient early detection of oral dysplastic lesions and early stages of oral squamous cell carcinoma.

VEGFA isoforms play a vital role in oral cancer progression.

Angiogenesis plays an important role in tumor growth and prognostication. A key angiogenesis stimulator is vascular endothelial growth factor (VEGF). The present investigation aimed to study contribution of VEGFA isoforms in oral cancer progression. Reverse transcription polymerase chain reaction and ELISA were employed to analyze tissue VEGFA isoforms and serum VEGF levels, respectively, in 109 oral cancer cases and 50 controls. VEGF183 and VEGF165 were significantly downregulated in malignant tissues as compared to adjacent normal tissues. VEGF183 and VEGF189 were significantly associated with tumor differentiation and tumor size. VEGF165 was significantly higher in recurrent early stage tumors. Serum VEGF levels were significantly higher in cases as compared to the controls and were associated with tumor differentiation. Serum VEGF levels were significantly higher in patients with recurrent advanced stage tumors. Further, patients with high levels of VEGF165 and serum VEGF levels had the worst prognosis. VEGFA isoform status and serum VEGF levels play a significant role in the progression as well as prognosis of oral cancer.

Salivary glyco-sialylation changes monitors oral carcinogenesis.

Alterations in cell membrane glycosylation play important role in oral carcinogenesis. The present study evaluated salivary sialylation changes i.e. total sialic acid (TSA), sialidase activity, linkage specific (α2-3 and α2-6) sialoproteins and sialyl transferase (ST) activity in controls, patients with oral precancerous conditions (OPC) and oral cancer. Subjects enrolled included 100 controls, 50 patients with OPC, 100 oral cancer patients, and 30 post treatment follow-ups. TSA was estimated by spectrophotometric method, sialidase activity by spectrofluorometric assay and linkage specific biotinylated lectins (α2-3: sambucus nigra agglutinin and α2-6: maackia amurensis agglutinin) were used to detect α-2,3 and α-2,6 STs and sialoproteins by ELISA and dot blot respectively. An increasing trend of salivary TSA/TP ratio, sialidase activity, α2-3 sialoproteins, α-2,3 and α-2,6 ST activities was observed from controls to patients with OPC to oral cancer patients and levels were significantly elevated in oral cancer patients as compared to the controls. Sialidase activity exhibited significant association with metastasis and infiltration. Sialidase activity, TSA/TP ratio, α-2,3 and α-2,6 ST activities were found to be higher in patients with metastasis as compared to patients without metastasis. A progressive increase in TSA/TP ratio, sialidase activity, α2-3 and α2-6 sialoproteins was observed from controls to early to advanced stage of the disease. Sialidase activity, α2-3 and α2-6 sialoproteins and ST activities were found to be decreased in complete responders; while levels were elevated in non-responders. The results documented utility of salivary sialylation endpoints, a non invasive tool in monitoring of oral carcinogenesis.

Prevalence of high-risk human papillomavirus type 16 and 18 in oral and cervical cancers in population from Gujarat, West India.

BACKGROUND: Oral and cervical cancers are major malignancies in men and women, respectively, in India. This study evaluated occurrence of human papillomavirus (HPV) 16 and 18 infections in oral and cervical cancers to estimate HPV-associated burden of these cancers in the population from Gujarat, West India. METHODS: A total of 97 malignant oral carcinoma tissues and 52 cervical carcinoma tissues were analyzed by type-specific PCR for the presence of HPV type 16 and 18 infections. RESULTS: None of the oral cancer patients revealed the presence of HPV type 16 and 18 infection. In cervical cancer, 31 (59.6%) patients were infected with HPV 16 and 18. Of these 31 HPV-positive cervical cancer patients, 28 (90.3%) were infected with HPV 16 and 3 (9.7%) were infected with HPV 18. CONCLUSION: The results suggested that HPV 16 and 18 do not play an important role in oral carcinogenesis in the population from Gujarat, West India. However, HPV 16 is highly prevalent in the cervical cancer patients, which may be considered for planning of prevention programs such as screening and vaccination in women from this region.

Evaluation of serum and salivary total sialic acid and α-l-fucosidase in patients with oral precancerous conditions and oral cancer.

OBJECTIVES: We compared serum and salivary total sialic acid/total protein (TSA/TP) ratios and α-l-fucosidase activity in patients with oral precancerous conditions (OPCs) and oral cancer to better understand the utility of saliva, in monitoring early changes occurring during oral cancer progression. STUDY DESIGN: A cross-sectional study of 100 oral cancer patients, 50 patients with OPC, and 100 controls was performed. RESULTS: Serum and salivary TSA/TP ratios and α-l-fucosidase activity were significantly higher in OPC and oral cancer patients compared to the controls. Also, levels were higher in controls and oral cancer patients with tobacco habits as compared to those without tobacco habits. CONCLUSION: Salivary TSA/TP ratio and α-l-fucosidase activity were elevated with higher magnitude than serum levels. These results suggest that a larger study may prove the use of these saliva biomarkers as a noninvasive method for detecting early changes occurring during oral carcinogenesis.

Association between p53 gene variants and oral cancer susceptibility in population from Gujarat, West India.

BACKGROUND: p53 gene variants i.e. 16 bp duplication in intron 3, Arg72Pro in exon 4 and G>A in intron 6 have been reported to modulate susceptibility to various malignancies. Therefore, the present study evaluated the role of these p53 polymorphisms in oral cancer susceptibility in a population from Gujarat, West India. METHOD: Genotype frequencies at the three p53 loci in 110 controls and 79 oral cancer cases were determined by the PCR-RFLP method. RESULTS: Heterozygous individuals at exon 4 showed protection from developing oral cancer. Homozygous wild and heterozygous individuals at intron 3 and those heterozygous at exon 4 in combination appeared to be at lowered risk. Furthermore, carriers of the 16 bp duplication allele at intron 3, proline allele at exon 4 and G allele at intron 6 were protected from oral cancer development. CONCLUSION: p53 polymorphisms, especially Arg72Pro in exon 4 could significantly modify the risk of oral cancer development in Gujarat, West Indian population.

Recent candidate molecular markers: vitamin D signaling and apoptosis specific regulator of p53 (ASPP) in breast cancer.

Regardless of advances in treatment modalities with the invention of newer therapies, breast cancer remains a major health problem with respect to its diagnosis, treatment and management. This female malignancy with its tremendous heterogeneous nature is linked to high incidence and mortality rates, especially in developing region of the world. It is the malignancy composed of distinct biological subtypes with diverse clinical, pathological, molecular and genetic features as well as different therapeutic responsiveness and outcomes. This inconsistency can be partially overcome by finding novel molecular markers with biological significance. In recent years, newer technologies help us to indentify distinct biomarkers and increase our understanding of the molecular basis of breast cancer. However, certain issues need to be resolved that limit the application of gene expression profiling to current clinical practice. Despite the complex nature of gene expression patterns of cDNAs in microarrays, there are some innovative regulatory molecules and functional pathways that allow us to predict breast cancer behavior in the clinic and provide new targets for breast cancer treatment. This review describes the landscape of different molecular markers with particular spotlight on vitamin D signaling pathway and apoptotic specific protein of p53 (ASPP) family members in breast cancer.

Glycoprotein electrophoretic patterns have potential to monitor changes associated with neoplastic transformation in oral cancer.

Alterations in glycoproteins, important cell surface constituents, have long been associated with various malignancies. The present investigation therefore explored the clinical significance of a glycoproteomics approach in patients with oral precancerous conditions (OPC) and patients with oral cancer. The study included 80 oral cancer patients, 50 patients with OPC, and 84 controls. Native polyacrylamide gel electrophoresis followed by Schiff's staining was carried out to study the alterations in glycoproteins. The results showed significant elevation (p<0.0001) of 192 kDa, 170 kDa, 116 kDa and 44 kDa glycoproteins in oral cancer patients and patients with OPC compared with controls. The odds ratio indicated a significantly higher risk for oral cancer among users and especially chewers of tobacco. The levels of all the glycoprotein bands (192 kDa, 170 kDa, 116 kDa and 44 kDa) were higher in patients with a habit of tobacco use (WHT) than in patients with no habit of tobacco (NHT) and were also higher in WHT controls than in NHT controls. Moreover, a 230 kDa glycoprotein consistently appeared only in individuals with tobacco habits and an increasing trend was observed from WHT controls to patients with OPC to WHT oral cancer patients. In conclusion, the results indicated the potential utility of glycoprotein alterations in monitoring sequential changes occurring due to tobacco consumption during neoplastic transformation.

Combined evaluation of matrix metalloproteinases and their inhibitors has better clinical utility in oral cancer.

BACKGROUND: Oral cancer is a major health hazard worldwide with increasing incidence and mortality. Cervical lymph node metastasis is a major determinant of outcome in oral cancer. The matrix metalloproteinase (MMP) system is critically involved in invasion and metastasis. Assessment of MMPs and tissue inhibitors of MMPs (TIMPs) in certain combinations might have better clinical efficacy given their potential role in the metastatic process. AIM: Plasma concentrations of MMP-2, MMP-9, TIMP-1 and TIMP-2 in 50 controls and 75 oral cancer patients (nonmetastatic, n=54; metastatic, n=21) were evaluated to assess their investigative value and role in predicting the behavior of this malignancy. METHODS: The plasma concentrations of MMP-2, MMP-9, TIMP-1 and TIMP-2 were quantified by ELISA. The best 2- and 3-marker combinations were calculated using the statistical software mROC. The diagnostic values for all the biomolecules as single markers and their combinations were estimated using the measures of diagnostic accuracy, i.e. the area under the ROC curve and the sensitivity and specificity at cutoff limits with the highest diagnostic accuracy and at the 95% limits of sensitivity and specificity, respectively. RESULTS: MMP-9, TIMP-1 and TIMP-2 were significantly elevated (p=0.000, p=0.013 and p=0.005, respectively) in oral cancer patients. MMP-9 emerged as the best single statistically significant marker in plasma for oral cancer detection. It showed an increase in diagnostic performance when tested in combination with MMP-2 and TIMP-2. The median plasma MMP-9 levels were elevated in both the metastatic and nonmetastatic groups compared with controls (p<0.004 and p<0.007, respectively). CONCLUSION: The results indicated that plasma MMP and TIMP levels in relevant combinations may facilitate clinical decisionmaking for improved management of oral cancer patients and may provide important data for selecting patients for treatment with drugs that interfere with MMP and TIMP activities.

A review on salivary genomics and proteomics biomarkers in oral cancer.

Oral cancer has emerged as an alarming public health problem with increasing incidence and mortality rates all over the world. Therefore, the implementation of newer screening and early detection approaches are of utmost importance which could reduce the morbidity and mortality associated with this disease. Sensitive and specific biomarkers for oral cancer are likely to be most effective for screening, diagnosis, staging and follow-up for this dreaded malignancy. Unlike other deep cancers, oral cancer is located in oral cavity. Hence, the direct contact between saliva and oral cancer lesion makes the measurement of tumor markers in saliva an attractive alternative to serum and tissue testing. The DNA, RNA and protein molecules derived from the living cancer cells can be conveniently obtained from saliva. Thus, salivary biomarkers, a non-invasive alternative to serum and tissue-based biomarkers may be an effective modality for early diagnosis, prognostication and monitoring post therapy status. In the current post-genomic era, various technologies provide opportunities for high-throughput approaches to genomics and proteomics; which have been used to evaluate altered expressions of gene and protein targets in saliva of oral cancer patients. The emerging field of salivary biomarkers has great potentials to prove its clinical significance to combat oral cancer. Hence, we have reviewed importance of several salivary genomics and proteomics biomarkers for oral cancer.

Matrix metalloproteinases and their inhibitors: correlation with invasion and metastasis in oral cancer.

Matrix metalloproteinases (MMPs) have been implicated in invasion and metastasis of various malignancies. The study evaluated a comprehensive profile of MMP-2 and MMP-9 and their inhibitors, tissue inhibitor of metalloproteinases-2 (TIMP-2) and tissue inhibitor of metalloproteinases-1 (TIMP-1), respectively in 50 controls and 75 patients with oral squamous cell carcinoma (OSCC). Blood samples from controls and patients as well as malignant and adjacent normal tissues from the patients were collected. The study examined pro, active and total forms of MMP-2 and MMP-9 using zymography. Enzyme-linked immunoassay (ELISA) and reverse transcription polymerase chain reaction were carried out to evaluate protein levels and mRNA expression; respectively, for the MMPs and TIMPs. Plasma pro, active and total MMP-2, MMP-9 as well as TIMP-1 and TIMP-2 levels were significantly higher in oral cancer patients as compared to the controls. mRNA expression of the MMPs and TIMPs was significantly higher in malignant tissues as compared to adjacent normal tissues. A significant positive correlation was observed between levels of proMMP-9 and active MMP-9 with differentiation, stage and infiltration. ProMMP-2 and active MMP-2 exhibited significant positive correlation with differentiation and lymph node involvement. The multivariate analysis of ELISA results revealed a significant positive correlation between MMP-2, TIMP-1 and TIMP-2 levels with lymph node involvement, stage and differentiation. The receiver operating characteristic curve (ROC) analysis showed that the levels of MMPs and TIMPs have significant discriminatory efficacy to differentiate between controls and patients. The results indicate that MMP-2, MMP-9, TIMP-1 and TIMP-2 have significant clinical usefulness for oral cancer patients. Zymographic analysis is a simple, cost effective, rapid and sensitive alternative assay.

Telomere attrition and telomerase activity are associated with GSTM1 polymorphism in oral cancer.

Telomere attrition is an important event during tumorigenesis regulated by factors including oxidative stress, mitochondrial function, DNA adducts etc. Critically short telomeres act as signal for telomerase activity in the cancer cells. To determine whether null genotype of GSTM1 gene has any association with telomere length shortening and telomerase activity, we analyzed telomere length, telomerase activity and GSTM1 polymorphism in oral tissues. We observed that malignant tissues exhibited shorter telomere length. Telomerase activity was observed in about 75% malignant tissues. 40% of the oral cancer patients exhibited GSTM1 polymorphism. Further, shorter telomere lengths were observed in patients having GSTM1 polymorphism. Also, the GSTM1 genotype showed negative correlation with telomerase activity and telomere length. Our study proposes role of GSTM1 polymorphism in telomere attrition and subsequent telomerase activity in the cancer cells. The results are suggestive of possible link between absence of GSTM1 gene and telomere length alterations.