Integrated proteomics and phosphoproteomics revealed druggable kinases in neoadjuvant chemotherapy resistant tongue cancer

Tongue squamous cell carcinoma is an aggressive oral cancer with a high incidence of metastasis and poor prognosis. Most of the oral cavity cancer patients present in clinics with locally advanced unresectable tumors. Neoadjuvant treatment is beneficial for these individuals as it reduces the tumor size aiding complete resection. However, patients develop therapy resistance to the drug regimen. In this study, we explored the differential expression of proteins and altered phosphorylation in the neoadjuvant chemotherapy resistant tongue cancer patients. We integrated the proteomic and phosphoproteomic profiles of resistant (n = 4) and sensitive cohorts (n = 4) and demonstrated the differential expression and phosphorylation of proteins in the primary tissue of the respective subject groups. We observed differential and extensive phosphorylation of keratins such as KRT10 and KRT1 between the two cohorts. Furthermore, our study revealed a kinase signature associated with neoadjuvant chemotherapy resistance. Kinases such as MAPK1, AKT1, and MAPK3 are predicted to regulate the resistance in non-responders. Pathway analysis showed enrichment of Rho GTPase signaling and hyperphosphosphorylation of proteins involved in cell motility, invasion, and drug resistance. Targeting the kinases could help with the clinical management of neoadjuvant chemotherapy-resistant tongue cancer

EGFR Mutations in Indian Lung Cancer Patients: Clinical Correlation and Outcome to EGFR Targeted Therapy

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Molecular biology of head and neck cancers

Head and Neck cancers constitute a real challenge for oncologists across the globe, with one person dying every hour of every day. It can distort and disfigure the face, strip away the voice and rob one of his basic abilities to eat, drink and swallow. The psychosocial impact can be extremely devastating. From previously being considered a homogenous entity, it is now a well recognized fact that Head and Neck cancer is rightly called “Head and neck cancers” in view of their genetic and molecular heterogeneity despite sharing histological and etiological homogeneity. The present review discusses recent insights as well as established principles of the molecular biology of Head and Neck Cancers

Elucidating the mechanisms of resistance to tyrosine kinase inhibitors in lung cancer patients

Introduction: Lung tumors with mutations in epidermal growth factor receptor (EGFR) gene represent a clinically distinct subtype of lung cancer and are observed at a frequency of 23% among Indian patients. The standard practice for treatment of EGFR mutated lung cancer patients includes tyrosine kinase inhibitors (TKIs) erlotinib and gefitinib. Although initial clinical responses are observed, resistance to TKIs develops within year from the start of treatment. In about fifty percent of cases, the resistance is caused due to a secondary T790M mutation in the EGFR gene. Additionally, MET amplification and histological transformation of tumors are known to confer TKI resistance in a small subset of patients. Nonetheless, there is an unmet need to elucidate novel ways by which lung tumors acquire resistance to EGFR targeting TKIs. Objectives: To delineate novel mechanisms of acquired resistance to EGFR-TKIs by characterizing the differential profile of drug sensitive and resistant state among lung tumors using integrated genomics approaches. Material and Methods: A retrospective collection of FFPE DNA samples (n=45) from tumors at baseline and rebiopsy along with paired blood sample was done for a total of 15 EGFR mutated lung cancer patients. Only tumor samples which were negative for EGFR T790M (as confirmed by orthologous technologies) were selected in the study with an anticipation that such samples would be enriched novel resistance mechanisms. Whole exome sequencing at an average coverage of 100X was performed for these samples. Results: The whole exome data was analyzed using an in-house developed pipeline. Of all the known resistance mutations, we identified EGFR T790M mutation in five out of fifteen patients. Other than T790M we expect to identify novel resistance causing mutations from the analysis of ten patients with unknown resistance mechanisms. Functional validation of these resistance specific alterations would be performed in vitro using drug sensitive lung cancer cell lines

Frequency of EGFR mutations in 907 lung adenocarcioma patients of Indian ethnicity.

BACKGROUND:During the past decade, the incidence of EGFR mutation has been shown to vary across different ethnicities. It occurs at the rate of 10-15% in North Americans and Europeans, 19% in African-Americans, 20-30% in various East Asian series including Chinese, Koreans, and Japanese. Frequency of EGFR mutations in India however remains sparsely explored. METHODOLOGY/PRINCIPAL FINDINGS:We report 23% incidence of Epidermal growth factor receptor (EGFR) mutations in 907 Non small cell lung cancer (NSCLC) patients of Indian ethnicity, in contrast to 10-15% known in Caucasians and 27-62% among East Asians. In this study, EGFR mutations were found to be more common in never-smokers 29.4% as compared to smokers 15.3%. Consistent with other populations, mutation rates among adenocarcinoma-males were predominantly lower than females with 32% incidence. However unlike Caucasians, EGFR mutation rate among adenocarcinoma-never-smoker females were comparable to males suggesting lack of gender bias among never smokers likely to benefit from EGFR targeted therapy. CONCLUSIONS/SIGNIFICANCE:This study has an overall implication for establishing relevance for routine EGFR mutation diagnostics for NSCLC patients in clinics and emphasizes effectiveness for adoption of EGFR inhibitors as the first line treatment among Indian population. The intermediate frequency of EGFR mutation among Indian population compared to Caucasians and East Asians is reminiscent of an ancestral admixture of genetic influence from Middle Easterners, Central Asians, and Europeans on modern- Indian population that may confer differential susceptibility to somatic mutations in EGFR

Comprehensive Development and Implementation of Good Laboratory Practice for NGS Based Targeted Panel on Solid Tumor FFPE Tissues in Diagnostics

The speed, accuracy, and increasing affordability of next-generation sequencing (NGS) have revolutionized the advent of precision medicine. To date, standardized validation criteria for diagnostic accreditation do not exist due to variability across the multitude of NGS platforms and within NGS processes. In molecular diagnostics, it is necessary to ensure that the primary material of the FFPE sample has good quality and optimum quantity for the analysis, otherwise the laborious and expensive NGS test may result in unreliable information. Therefore, stringent quality control of DNA and RNA before, during, and after library preparation is an essential parameter. Considering the various challenges with the FFPE samples, we aimed to set a benchmark in QC metrics that can be utilized by molecular diagnostic laboratories for successful library preparation and high-quality NGS data output. In total, 144 DNA and 103 RNA samples of various cancer types with a maximum storage of 2 years were processed for 52 gene focus panels. During the making of DNA and RNA libraries, extensive QC check parameters were imposed at different checkpoints. The decision tree approach can be set as a benchmark for FFPE samples and as a guide to establishing a good clinical laboratory practice for targeted NGS panels