Browsing by Author "Chintala, Sreenivasulu"
Now showing 1 - 10 of 14
Results Per Page
Sort Options
Item Cervical Cancer Development: Implications of HPV16 E6E7-NFX1-123 Regulated Genes(MDPI, 2021-12-08) Quist, Kevin M.; Solorzano, Isaiah; Wendel, Sebastian O.; Chintala, Sreenivasulu; Wu, Cen; Wallace, Nicholas A.; Katzenellenbogen, Rachel A.; Pediatrics, School of MedicineHigh-risk human papillomavirus (HR HPV) causes nearly all cervical cancers, half of which are due to HPV type 16 (HPV16). HPV16 oncoprotein E6 (16E6) binds to NFX1-123, and dysregulates gene expression, but their clinical implications are unknown. Additionally, HPV16 E7's role has not been studied in concert with NFX1-123 and 16E6. HR HPVs express both oncogenes, and transformation requires their expression, so we sought to investigate the effect of E7 on gene expression. This study's goal was to define gene expression profiles across cervical precancer and cancer stages, identify genes correlating with disease progression, assess patient survival, and validate findings in cell models. We analyzed NCBI GEO datasets containing transcriptomic data linked with cervical cancer stage and utilized LASSO analysis to identify cancer-driving genes. Keratinocytes expressing 16E6 and 16E7 (16E6E7) and exogenous NFX1-123 were tested for LASSO-identified gene expression. Ten out of nineteen genes correlated with disease progression, including CEBPD, NOTCH1, and KRT16, and affected survival. 16E6E7 in keratinocytes increased CEBPD, KRT16, and SLPI, and decreased NOTCH1. Exogenous NFX1-123 in 16E6E7 keratinocytes resulted in significantly increased CEBPD and NOTCH1, and reduced SLPI. This work demonstrates the clinical relevance of CEBPD, NOTCH1, KRT16, and SLPI, and shows the regulatory effects of 16E6E7 and NFX1-123.Item Common Molecular Alterations in Canine Oligodendroglioma and Human Malignant Gliomas and Potential Novel Therapeutic Targets(Frontiers, 2019-08-14) Mitchell, Dana; Chintala, Sreenivasulu; Fetcko, Kaleigh; Henriquez, Mario; Tewari, Brij N.; Ahmed, Atique; Bentley, R. Timothy; Dey, Mahua; Neurological Surgery, School of MedicineSpontaneous canine (Canis lupus) oligodendroglioma (ODG) holds tremendous potential as an immunocompetent large animal model of human malignant gliomas (MG). However, the feasibility of utilizing this model in pre-clinical studies depends on a thorough understanding of the similarities and differences of the molecular pathways associated with gliomas between the two species. We have previously shown that canine ODG has an immune landscape and expression pattern of commonly described oncogenes similar to that of human MG. In the current study, we performed a comprehensive analysis of canine ODG RNAseq data from 4 dogs with ODG and 2 normal controls to identify highly dysregulated genes in canine tumors. We then evaluated the expression of these genes in human MG using Xena Browser, a publicly available database. STRING-database inquiry was used in order to determine the suggested protein associations of these differentially expressed genes as well as the dysregulated pathways commonly enriched by the protein products of these genes in both canine ODG and human MG. Our results revealed that 3,712 (23%) of the 15,895 differentially expressed genes demonstrated significant up- or downregulation (log2-fold change > 2.0). Of the 3,712 altered genes, ~50% were upregulated (n = 1858) and ~50% were downregulated (n = 1854). Most of these genes were also found to have altered expression in human MG. Protein association and pathway analysis revealed common pathways enriched by members of the up- and downregulated gene categories in both species. In summary, we demonstrate that a similar pattern of gene dysregulation characterizes both human MG and canine ODG and provide additional support for the use of the canine model in order to therapeutically target these common genes. The results of such therapeutic targeting in the canine model can serve to more accurately predict the efficacy of anti-glioma therapies in human patients.Item EZH2 modifies sunitinib resistance in renal cell carcinoma by kinome reprogramming(Cancer Research, 2017-12-01) Adelaiye-Ogala, Remi; Budka, Justin; Damayanti, Nur P.; Arrington, Justine; Ferris, Mary; Hsu, Chuan-Chih; Chintala, Sreenivasulu; Orillion, Ashley; Miles, Kiersten Marie; Shen, Li; Elbanna, May; Ciamporcero, Eric; Arisa, Sreevani; Pettazzoni, Piergiorgio; Draetta, Giulio F.; Seshadri, Mukund; Hancock, Bradley; Radovich, Milan; Kota, Janaiah; Buck, Michael; Keilhack, Heike; McCarthy, Brian P.; Persohn, Scott A.; Territo, Paul R.; Zang, Yong; Irudayaraj, Joseph; Tao, W. Andy; Hollenhorst, Peter; Pili, RobertoAcquired and intrinsic resistance to receptor tyrosine kinase inhibitors (RTKi) represent a major hurdle in improving the management of clear cell renal cell carcinoma (ccRCC). Recent reports suggest that drug resistance is driven by tumor adaptation via epigenetic mechanisms that activate alternative survival pathways. The histone methyl transferase EZH2 is frequently altered in many cancers including ccRCC. To evaluate its role in ccRCC resistance to RTKi, we established and characterized a spontaneously metastatic, patient-derived xenograft (PDX) model that is intrinsically resistant to the RTKI sunitinib but not to the VEGF therapeutic antibody bevacizumab. Sunitinib maintained its anti-angiogenic and anti-metastatic activity but lost its direct anti-tumor effects due to kinome reprogramming, which resulted in suppression of pro- apoptotic and cell cycle regulatory target genes. Modulating EZH2 expression or activity suppressed phosphorylation of certain RTK, restoring the anti-tumor effects of sunitnib in models of acquired or intrinsically resistant ccRCC. Overall, our results highlight EZH2 as a rational target for therapeutic intervention in sunitinib-resistant ccRCC as well as a predictive marker for RTKi response in this disease.Item Genes Regulated by HPV 16 E6 and High Expression of NFX1-123 in Cervical Cancers(Dove Press, 2020-06-26) Chintala, Sreenivasulu; Levan, Justine; Robinson, Kristin; Quist, Kevin; Katzenellenbogen, Rachel A.; Pediatrics, School of MedicinePurpose High-risk human papillomaviruses (HR HPV) cause cervical cancer, and in these cancers, HPV type 16 is the most common HR type. The HR viral oncogenes E6 and E7 partner with cellular proteins to drive cancer and modulate immune pathways; previously, we demonstrated in keratinocytes that HPV 16 E6 and high expression of the endogenous host protein partner NFX1-123 led to the increased expression of multiple genes, including Notch1, secretory leukocyte peptidase inhibitor (SLPI), and retinoic acid early transcript 1G (RAET1G). The present study was conducted to determine if NFX1-123 was highly expressed in cervical cancer and if genes increased by NFX1-123 and 16E6 in keratinocytes were also increased in cervical cancers. Materials and Methods The Cancer Genome Atlas (TCGA) database and The Human Protein Atlas database were used to compare relative mRNA and protein gene expression, respectively, in the normal cervix and cervical cancers. Formalin-fixed paraffin-embedded (FFPE) normal cervix and HPV 16 positive cervical cancer samples were analyzed for relative protein expression by immunohistochemical staining. Protein expression of a subset of regulated genes was quantified by Western blot of HPV positive and negative cell lines. Results Immunohistochemical staining of HPV 16 positive cervical dysplasias and cancers revealed high NFX1-123, Ki67, and Notch1 expression. NFX1 and NFX1L1 mRNA levels were increased in cervical cancers compared to normal cervix in the TCGA database. Fourteen genes previously identified as upregulated in keratinocytes with 16E6 and overexpressed NFX1-123 also had high mRNA expression and selected genes had high protein expression in cervical cancers and cell lines. Conclusion In cervical cancer, NFX1-123 is highly expressed, and 16E6 and NFX1-123 together alter the expression of a wide set of genes. The involvement of these genes in cell proliferation, differentiation, invasion, and metastasis provides further insight into potential ways that HR HPVs promote cancer initiation and maintenance.Item Genome wide DNA methylation landscape reveals glioblastoma’s influence on epigenetic changes in tumor infiltrating CD4+ T cells(Impact Journals, 2021-05-11) Bam, Marpe; Chintala, Sreenivasulu; Fetcko, Kaleigh; Williamsen, Brooke Carmen; Siraj, Seema; Liu, Sheng; Wan, Jun; Xuei, Xiaoling; Liu, Yunlong; Leibold, Adam T.; Dey, Mahua; Neurological Surgery, School of MedicineCD4+ helper T (Th) cells play a critical role in shaping anti-tumor immunity by virtue of their ability to differentiate into multiple lineages in response to environmental cues. Various CD4+ lineages can orchestrate a broad range of effector activities during the initiation, expansion, and memory phase of endogenous anti-tumor immune response. In this clinical corelative study, we found that Glioblastoma (GBM) induces multi- and mixed-lineage immune response in the tumor microenvironment. Whole-genome bisulfite sequencing of tumor infiltrating and blood CD4+ T-cell from GBM patients showed 13571 differentially methylated regions and a distinct methylation pattern of methylation of tumor infiltrating CD4+ T-cells with significant inter-patient variability. The methylation changes also resulted in transcriptomic changes with 341 differentially expressed genes in CD4+ tumor infiltrating T-cells compared to blood. Analysis of specific genes involved in CD4+ differentiation and function revealed differential methylation status of TBX21, GATA3, RORC, FOXP3, IL10 and IFNG in tumor CD4+ T-cells. Analysis of lineage specific genes revealed differential methylation and gene expression in tumor CD4+ T-cells. Interestingly, we observed dysregulation of several ligands of T cell function genes in GBM tissue corresponding to the T-cell receptors that were dysregulated in tumor infiltrating CD4+ T-cells. Our results suggest that GBM might induce epigenetic alterations in tumor infiltrating CD4+ T-cells there by influencing anti-tumor immune response by manipulating differentiation and function of tumor infiltrating CD4+ T-cells. Thus, further research is warranted to understand the role of tumor induced epigenetic modification of tumor infiltrating T-cells to develop effective anti-GBM immunotherapy.Item Genomic profiling of collecting duct renal carcinoma(Impact Journals, LLC, 2016-10-26) Chintala, Sreenivasulu; Pili, Roberto; Department of Neurological Surgery, School of MedicineItem High Expression of NFX1-123 in HPV Positive Head and Neck Squamous Cell Carcinomas(Wiley, 2022) Chintala, Sreenivasulu; Quist, Kevin M.; Gonzalez-DeWhitt, Patricia A.; Katzenellenbogen, Rachel A.; Pediatrics, School of MedicineBackground: High-risk human papillomaviruses (HR HPV) cause nearly all cervical cancers and, in the United States, the majority of head and neck cancers (HNSCCs). NFX1-123 is overexpressed in cervical cancers, and NFX1-123 partners with the HR HPV type 16 E6 oncoprotein to affect multiple growth, differentiation, and immune response genes. However, neither the expression of NFX1-123 nor the levels of these genes have been investigated in HPV positive (HPV+) or negative (HPV-) HNSCCs. Methods: The Cancer Genome Atlas Splicing Variants Database and HNSCC cell lines were used to quantify expression of NFX1-123 and cellular genes increased in cervical cancers. Results: NFX1-123 was increased in HPV+ HNSCCs compared to HPV- HNSCCs. LCE1B, KRT16, SPRR2G, and FBN2 were highly expressed in HNSCCs compared to normal tissues. Notch1 and CCNB1IP1 had greater expression in HPV+ HNSCCs compared to HPV- HNSCCs. Conclusion: NFX1-123 and a subset of its known targets were increased in HPV+ HNSCCs.Item NFX1, Its Isoforms and Roles in Biology, Disease and Cancer(MDPI, 2021-03-30) Chintala, Sreenivasulu; Katzenellenbogen, Rachel A.; Pediatrics, School of MedicineIn 1989, two NFX1 protein products were identified as nuclear proteins with the ability to bind to X-box cis-elements. Since that publication, the NFX1 gene and its homologs have been identified, from yeast to humans. This review article summarizes what is known about the NFX1 gene across species. We describe the gene and protein motifs of NFX1 homologs and their functions in cellular biology, then turn to NFX1 in human biology and disease development. In that, we focus on more recent literature about NFX1 and its two splice variants protein products (NFX1-91 and NFX1-123) that are expressed in epithelial cells. We describe new evidence of conserved protein motifs, direct and indirect gene expression regulation, and critical protein-protein interactions. Finally, we stress the emerging roles of these NFX1 splice variants in high-risk human papillomavirus-associated cancers, and the increased expression of the longer splice variant, NFX1-123, found in these cancers.Item NFX1-123: A potential therapeutic target in cervical cancer(Wiley, 2023) Chintala, Sreenivasulu; Dankoski, Maura A.; Anbarasu, Anand; Ramaiah, Sudha; Miryala, Sravan Kumar; Katzenellenbogen, Rachel A.; Pediatrics, School of MedicineNFX1-123 is a splice variant isoform of the NFX1 gene. It is highly expressed in cervical cancers caused by HPV, and NFX1-123 is a protein partner with the HPV oncoprotein E6. Together, NFX1-123 and E6 affect cellular growth, longevity, and differentiation. The expression status of NFX1-123 in cancers beyond cervical and head and neck cancers, and its potential as therapeutic target, have not been investigated. TSVdb of TCGA was used to quantify NFX1-123 expression in 24 cancers compared with normal tissues. The NFX1-123 protein structure was predicted and then submitted to retrieve suitable drug molecules. The top four compounds, found to bind in silico to NFX1-123, were tested experimentally to determine their effects on NFX1-123-related cellular growth, survival, and migration. 46% of cancers (11 of 24 had significant differences in NFX1-123 expression, with nine having had greater NFX1-123 expression, when compared with adjacent normal tissues. Bioinformatics and proteomic predictive analysis modeled the three-dimensional structure of NFX1-123, and drug libraries were screened for high-binding affinity compounds using this modeled structure. Seventeen drugs with binding energies ranging from -1.3 to -10 Kcal/mol were identified. The top four compounds were used to treat HPV- and HPV+ cervical cancer cell lines, three of which (Ropitoin, R428 and Ketoconazole) reduced NFX1-123 protein levels, inhibited cellular growth, survival, and migration, and enhanced the cytotoxicity of Cisplatin. These findings highlight cancers expressing high levels of NFX1-123, and drugs that target it, may reduce cellular growth, survival, and migration, making NFX1-123 a potential novel therapeutic target.Item Non-Coding Micro RNAs and Hypoxia-Inducible Factors Are Selenium Targets for Development of a Mechanism-Based Combination Strategy in Clear-Cell Renal Cell Carcinoma—Bench-to-Bedside Therapy(MDPI, 2018-10-29) Rustum, Youcef M.; Chintala, Sreenivasulu; Durrani, Farukh A.; Bhattacharya, Arup; Neurological Surgery, School of MedicineDurable response, inherent or acquired resistance, and dose-limiting toxicities continue to represent major barriers in the treatment of patients with advanced clear-cell renal cell carcinoma (ccRCC). The majority of ccRCC tumors are characterized by the loss of Von Hippel⁻Lindau tumor suppressor gene function, a stable expression of hypoxia-inducible factors 1α and 2α (HIFs), an altered expression of tumor-specific oncogenic microRNAs (miRNAs), a clear cytoplasm with dense lipid content, and overexpression of thymidine phosphorylase. The aim of this manuscript was to confirm that the downregulation of specific drug-resistant biomarkers deregulated in tumor cells by a defined dose and schedule of methylselenocysteine (MSC) or seleno-l-methionine (SLM) sensitizes tumor cells to mechanism-based drug combination. The inhibition of HIFs by selenium was necessary for optimal therapeutic benefit. Durable responses were achieved only when MSC was combined with sunitinib (a vascular endothelial growth factor receptor (VEGFR)-targeted biologic), topotecan (a topoisomerase 1 poison and HIF synthesis inhibitor), and S-1 (a 5-fluorouracil prodrug). The documented synergy was selenium dose- and schedule-dependent and associated with enhanced prolyl hydroxylase-dependent HIF degradation, stabilization of tumor vasculature, downregulation of 28 oncogenic miRNAs, as well as the upregulation of 12 tumor suppressor miRNAs. The preclinical results generated provided the rationale for the development of phase 1/2 clinical trials of SLM in sequential combination with axitinib in ccRCC patients refractory to standard therapies.