Harikrishna Nakshatri

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https://hdl.handle.net/1805/17677

Enhancing Hormone Therapy and Chemotherapy Sensitivity of Breast Cancer

Breast cancers are broadly classified into estrogen receptor positive (ER+) and estrogen receptor negative (ER-) subtypes. Anti-estrogens (hormone therapy) and chemotherapy are treatment options for ER+ and ER- breast cancers, respectively. However, resistance to therapies is very common, and disease recurrence is associated with the spread of the diseases to multiple organs (metastasis). Dr. Nakshatri's research lab focuses on mechanisms of resistance to anti-estrogens and chemotherapy, predicting therapy resistance at the time of diagnosis, and developing effective combination therapies, particularly for metastasis.

His group has identified and commercialized biomarkers that may predict response to anti-estrogens, demonstrating that a protein complex min a subset of breast cancer plays a role in chemotherapy resistance and metastasis-research that, in collaboration with other institutions, is currently in phase I clinical trial. Additional work included circulating biomarkers that predict the effect of breast cancer on the general well-being of a patient and a new patent application on how to treat specific subtypes of breast cancer. His group also established a culturing method to grow and genomically characterize primary tumors and metastasis at the individual level.

Dr. Nakshatri's work to identify biomarkers of disease progression is another example of how IUPUI faculty are TRANSLATING RESEARCH INTO PRACTICE.

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Now showing 1 - 10 of 11

AKT Alters Genome-Wide Estrogen Receptor α Binding and Impacts Estrogen Signaling in Breast Cancer
(American Society for Microbiology, 2008-12) Bhat-Nakshatri, Poornima; Wang, Guohua; Appaiah, Hitesh; Luktuke, Nikhil; Carroll, Jason S.; Geistlinger, Tim R.; Brown, Myles; Badve, Sunil; Liu, Yunlong; Nakshatri, Harikrishna
Estrogen regulates several biological processes through estrogen receptor α (ERα) and ERβ. ERα-estrogen signaling is additionally controlled by extracellular signal activated kinases such as AKT. In this study, we analyzed the effect of AKT on genome-wide ERα binding in MCF-7 breast cancer cells. Parental and AKT-overexpressing cells displayed 4,349 and 4,359 ERα binding sites, respectively, with ∼60% overlap. In both cell types, ∼40% of estrogen-regulated genes associate with ERα binding sites; a similar percentage of estrogen-regulated genes are differentially expressed in two cell types. Based on pathway analysis, these differentially estrogen-regulated genes are linked to transforming growth factor β (TGF-β), NF-κB, and E2F pathways. Consistent with this, the two cell types responded differently to TGF-β treatment: parental cells, but not AKT-overexpressing cells, required estrogen to overcome growth inhibition. Combining the ERα DNA-binding pattern with gene expression data from primary tumors revealed specific effects of AKT on ERα binding and estrogen-regulated expression of genes that define prognostic subgroups and tamoxifen sensitivity of ERα-positive breast cancer. These results suggest a unique role of AKT in modulating estrogen signaling in ERα-positive breast cancers and highlights how extracellular signal activated kinases can change the landscape of transcription factor binding to the genome.
ANTXR1, a stem cell enriched functional biomarker, connects collagen signaling to cancer stem-like cells and metastasis in breast cancer
(American Association for Cancer Research, 2013-09-15) Chen, Daohong; Bhat-Nakshatri, Poornima; Goswami, Chirayu; Badve, Sunil; Nakshatri, Harikrishna
Cancer stem-like cells are thought to contribute to tumor recurrence. The anthrax toxin receptor ANTXR1 has been identified as a functional biomarker of normal stem cells and breast cancer stem-like cells. Primary stem cell-enriched basal cells (CD49f+/EpCAM−/Lin−) expressed higher levels of ANTXR1 compared to mature luminal cells. CD49f+/EpCAM−, CD44+/EpCAM−, CD44+/CD24− or ALDEFLUOR-positive subpopulations of breast cancer cells were enriched for ANTXR1 expression. CD44+/CD24−/ANTXR1+ cells displayed enhanced self-renewal as measured by mammosphere assay compared to CD44+/CD24−/ANTXR1− cells. Activation of ANTXR1 by its natural ligand C5A, a fragment of collagen VI α3, increased stem cell self-renewal in mammosphere assays and Wnt signaling including the expression of the Wnt receptor LRP6, phosphorylation of GSK3α/β and elevated expression of Wnt target genes. RNAi-mediated silencing of ANTXR1 enhanced the expression of luminal-enriched genes but diminished Wnt signaling including reduced LRP6 and ZEB1 expression, self-renewal, invasion, tumorigenicity and metastasis. ANTXR1 silencing also reduced the expression of HSPA1A, which is overexpressed in metastatic breast cancer stem cells. Analysis of public databases revealed ANTXR1 amplification in medullary breast carcinoma and overexpression in estrogen receptor-negative breast cancers with the worst outcome. Further, ANTXR1 is among the 10% most overexpressed genes in breast cancer and is co-expressed with collagen VI. Thus, ANTXR1:C5A interactions bridge a network of collagen cleavage and remodeling in the tumor microenvironment, linking it to a stemness signaling network drives metastatic progression.
Identification of FDA-approved Drugs Targeting Breast Cancer Stem Cells Along With Biomarkers of Sensitivity
(Nature Research, 2013-08-28) Bhat-Nakshatri, Poornima; Goswami, Chirayu P.; Badve, Sunil; Sledge, George W.; Nakshatri, Harikrishna
Recently developed genomics-based tools are allowing repositioning of Food and Drug Administration (FDA)-approved drugs as cancer treatments, which were employed to identify drugs that target cancer stem cells (CSCs) of breast cancer. Gene expression datasets of CSCs from six studies were subjected to connectivity map to identify drugs that may ameliorate gene expression patterns unique to CSCs. All-trans retinoic acid (ATRA) was negatively connected with gene expression in CSCs. ATRA reduced mammosphere-forming ability of a subset of breast cancer cells, which correlated with induction of apoptosis, reduced expression of SOX2 but elevated expression of its antagonist CDX2. SOX2/CDX2 ratio had prognostic relevance in CSC-enriched breast cancers. K-ras mutant breast cancer cell line enriched for CSCs was resistant to ATRA, which was reversed by MAP kinase inhibitors. Thus, ATRA alone or in combination can be tested for efficacy using SOX2, CDX2, and K-ras mutation/MAPK activation status as biomarkers of response.
Indiana Center for Breast Cancer Research
(Office of the Vice Chancellor for Research, 2014-04-11) Nakshatri, Harikrishna; Gilley, David P.; Wells, Clark D.; Nephew, Kenneth; Radovich, Milan; Guise, Theresa; Bales, Casey; Perkins, Susan; Badve, Sunil; Vladislav, Ioan Tudor; Miller, Kathy
The mission of IUPUI breast cancer signature center is to address prevention, early detection, and treatment of breast cancer through translational projects, supportive cores, and synergistic programs. This poster details our efforts improve resources for breast cancer research and efforts to develop multi-PI investigator proposals. The Signature Center has developed two web resources: the Breast Cancer Prognostics Database (PROGgene) to study prognostic implications of genes of interest in publically available breast cancer databases and PROGmiR, a microRNA database. The PROGgene can be used to study overall, recurrence free and metastasis free survival in large patient series. PROGmiR allows investigators to study the prognostic importance of microRNAs. Both PROGgene and PROGmiR have recently been published and accessed by investigators from >10 countries. The signature center has also devoted considerable efforts in developing tumor tissue resource. Tissue Bank includes a total sample of N = 600 cases with 30% non-Caucasian cases. Currently 460 cases have been assembled into a Tissue Microarray with clinical and follow up data. Expression pattern of AP2γ, a potential marker of breast cancer progression, has been analyzed in a TMA with ~170 cases. The breast cancer signature center has funded four pilot projects and projects for the fourth round of funding are currently under review. Drs. Clark Wells received funding for the project “Histologic Analysis of the Protein Levels of Amot130, AmotL1 and YAP in Normal, Hyperplastic and Invasive Breast Cancer Tissues”, which resulted in a publication in PNAS. Dr. David Gilley and his group received funding for the project: “Luminal mammary progenitors are a unique site of telomere dysfunction”, which was published in Stem Cell Reports. In the third project, Dr. Theresa Guise is investigating the mechanisms of cancer-associated muscular dysfunction with a future plan for a clinical trial. Drs. Ken Nephew and Milan Radovich received funding to obtain preliminary results for a multi-PI R01 or P01, which will explore genomics and epigenomics of breast cancer using clinical trial materials. Progress made by the signature center was integral in our request to Vera Bradley Foundation for Breast Cancer. This foundation has recently committed $15 million for the breast cancer program, which will be used to develop three themes of research with a focus on personalized therapies to improve outcome in breast cancer patients.
THE INDIANA CENTER FOR BREAST CANCER RESEARCH: PROGRESS REPORT
(Office of the Vice Chancellor for Research, 2013-04-05) Nakshatri, Harikrishna; Sledge, George W., Jr.; Badve, Sunil; Bales, Casey; Gilley, David P.; Goswami, Chirayu; Wells, Clark D.; Guise, Theresa; Ziner, Kim W.
The mission of IUPUI breast cancer center is to address prevention, early detection, and treatment of breast cancer through translational projects, supportive cores, and synergistic programs. This poster details our efforts improve resources for breast cancer research and efforts to develop multi-PI investigator proposals. The Signature Center Initiative has developed two web resources: the Breast Cancer Prognostics Database (BCDB) to study prognostic implications of genes of interest in publically available breast cancer databases and PROGmiR, a microRNA database. The BCDB can be used to study overall, recurrence free and metastasis free survival in large patient series. PROGmiR allows investigators to study the prognostic importance of microRNAs. PROGmiR has recently been published and has been accessed by investigators from several countries. The signature center has also devoted considerable efforts in developing tumor tissue resource. Tissue Bank includes a total sample of N = 500 cases with 30% non-Caucasian cases from Wishard Memorial Hospital. Currently 237 cases have been assembled into a Tissue Microarray with clinical and follow up data. The breast cancer center has funded three pilot projects. Drs. Clark Wells, S. Badve, and G. Sandusky are collaborating on the project: “Histologic Analysis of the Protein Levels of Amot130, AmotL1 and YAP in Normal, Hyperplastic and Invasive Breast Cancer Tissues”. This project is investigating localized protein expression in paraffin-embedded tissues to associate expression levels with disease subtype and patient outcome. Dr. David Gilley and his group are collaborating on the project: “Luminal mammary progenitors are a unique site of telomere dysfunction”. This project is investigating the relationship between telomere dysfunction and breast cancer tumorigenesis. In the third project, Dr. Theresa Guise will be investigating the mechanisms of cancer-associated cachexia. Several multi-PI proposals are under preparation and one proposal with Drs. Nakshatri and Kathy Miller as PIs is currently under review.
The Indiana Center for Breast Cancer Research: Progress towards a SPORE Proposal
(Office of the Vice Chancellor for Research, 2012-04-13) Sledge Jr., George W.; Badve, Sunil; Bales, Casey; Gill, Erin M.; Gilley, David P.; Goswami, Chirayu; Wells, Clark D.; Ziner, Kim W.; Nakshatri, Harikrishna
Abstract The Indiana Center for Breast Cancer Research (ICBCR) was funded under the IUPUI Signature Center Initiative in 2010. Its mission is to address the full range of prevention, early detection, and treatment of breast cancer through translational projects, supportive cores, and synergistic programs. This poster details our efforts to date towards applying for a National Cancer Institute Specialized Program of Research Excellence (SPORE) in January 2013. The proposed IU Breast Cancer SPORE will include 4-5 individual research projects, 3 cores, developmental research and career development programs. The SPORE Biostatistics and Bioinformatics core has developed the Breast Cancer Prognostics Database (BCDB), an online tool to study prognostic implications of genes of interest in publically available breast cancer databases. The BCDB can be used to study overall, recurrence free and metastasis free survival in large patient series. Supporting the SPORE Biospecimen/Pathology core, the IU Breast Cancer Tissue Bank includes a total sample of N = 500 cases with 30% non-Caucasian cases from Wishard Memorial Hospital. Currently there are N = 333 cases with tissue microarray data and complete clinical data with an additional 200 cases pending tissue confirmation. Dr. Clark D. Wells together with S. Badve and G. Sandusky are collaborating on the project: “Histologic Analysis of the Protein Levels of Amot130, AmotL1 and YAP in Normal, Hyperplastic and Invasive Breast Cancer Tissues”, a candidate SPORE individual research project. This project is investigating localized protein expression in paraffin-embedded tissues to associate expression levels with disease subtype and patient outcome. Dr. David P. Gilley together with N. Kannan, N. Huda, L. Tu, R. Droumeva, R. Brinkman, J. Emerman, S. Abe, and C. Eaves, are collaborating on the project: “Luminal mammary progenitors are a unique site of telomere dysfunction”, a candidate SPORE developmental research project. This project is investigating the relationship between telomere dysfunction and breast cancer tumorigenesis. These SPORE projects and cores were discussed at the IUSCC Breast Cancer Program retreat held on 1/13/12. Two additional planning meetings were held on 1/5 and 2/23. A timeline was generated to include final project selection in April, internal review in June, external review in August-September, and draft completion by 12/1, to meet the 1/20/13 NIH receipt deadline.
Molecular Insights of Pathways Resulting From Two Common PIK3CA Mutations in Breast Cancer
(AACR, 2016-07) Bhat-Nakshatri, Poornima; Goswami, Chirayu P.; Badve, Sunil; Magnani, Luca; Lupien, Mathieu; Nakshatri, Harikrishna; Department of Surgery, IU School of Medicine
The PI3K pathway is activated in approximately 70% of breast cancers. PIK3CA gene mutations or amplifications that affect the PI3K p110α subunit account for activation of this pathway in 20% to 40% of cases, particularly in estrogen receptor alpha (ERα)-positive breast cancers. AKT family of kinases, AKT1–3, are the downstream targets of PI3K and these kinases activate ERα. Although several inhibitors of PI3K have been developed, none has proven effective in the clinic, partly due to an incomplete understanding of the selective routing of PI3K signaling to specific AKT isoforms. Accordingly, we investigated in this study the contribution of specific AKT isoforms in connecting PI3K activation to ERα signaling, and we also assessed the utility of using the components of PI3K–AKT isoform–ERα signaling axis as predictive biomarkers of response to PI3K inhibitors. Using a variety of physiologically relevant model systems with defined natural or knock-in PIK3CA mutations and/or PI3K hyperactivation, we show that PIK3CA-E545K mutations (found in ∼20% of PIK3CA-mutant breast cancers), but not PIK3CA-H1047R mutations (found in 55% of PIK3CA-mutant breast cancers), preferentially activate AKT1. Our findings argue that AKT1 signaling is needed to respond to estrogen and PI3K inhibitors in breast cancer cells with PIK3CA-E545K mutation, but not in breast cancer cells with other PIK3CA mutations. This study offers evidence that personalizing treatment of ER-positive breast cancers to PI3K inhibitor therapy may benefit from an analysis of PIK3CA–E545K–AKT1–estrogen signaling pathways.
NF-κB-dependent and -independent epigenetic modulation using the novel anti-cancer agent DMAPT
(Nature Publishing Group, 2015-01-22) Nakshatri, H.; Appaiah, H. N.; Anjanappa, M.; Gilley, D.; Tanaka, H.; Badve, Sunil; Crooks, P. A.; Mathews, W.; Sweeney, C.; Bhat-Nakshatri, P.; Department of Surgery, IU School of Medicine
The transcription factor nuclear factor-kappaB (NF-κB) is constitutively active in several cancers and is a target of therapeutic development. We recently developed dimethylaminoparthenolide (DMAPT), a clinical grade water-soluble analog of parthenolide, as a potent inhibitor of NF-κB and demonstrated in vitro and in vivo anti-tumor activities in multiple cancers. In this study, we show DMAPT is an epigenetic modulator functioning in an NF-κB-dependent and -independent manner. DMAPT-mediated NF-κB inhibition resulted in elevated histone H3K36 trimethylation (H3K36me3), which could be recapitulated through genetic ablation of the p65 subunit of NF-κB or inhibitor-of-kappaB alpha super-repressor overexpression. DMAPT treatment and p65 ablation increased the levels of H3K36 trimethylases NSD1 (KMT3B) and SETD2 (KMT3A), suggesting that NF-κB directly represses their expression and that lower H3K36me3 is an epigenetic marker of constitutive NF-κB activity. Overexpression of a constitutively active p65 subunit of NF-κB reduced NSD1 and H3K36me3 levels. NSD1 is essential for DMAPT-induced expression of pro-apoptotic BIM, indicating a functional link between epigenetic modification and gene expression. Interestingly, we observed enhanced H4K20 trimethylation and induction of H4K20 trimethylase KMT5C in DMAPT-treated cells independent of NF-κB inhibition. These results add KMT5C to the list NF-κB-independent epigenetic targets of parthenolide, which include previously described histone deacetylase 1 (HDAC-1) and DNA methyltransferase 1. As NSD1 and SETD2 are known tumor suppressors and loss of H4K20 trimethylation is an early event in cancer progression, which contributes to genomic instability, we propose DMAPT as a potent pharmacologic agent that can reverse NF-κB-dependent and -independent cancer-specific epigenetic abnormalities.
Organ-specific adaptive signaling pathway activation in metastatic breast cancer cells
(Impact Journals, LLC, 2015-05-20) Burnett, Riesa M.; Craven, Kelly E.; Krishnamurthy, Purna; Goswami, Chirayu P.; Badve, Sunil; Crooks, Peter; Mathews, William P.; Bhat-Nakshatri, Poornima; Nakshatri, Harikrishna; Department of Surgery, IU School of Medicine
Breast cancer metastasizes to bone, visceral organs, and/or brain depending on the subtype, which may involve activation of a host organ-specific signaling network in metastatic cells. To test this possibility, we determined gene expression patterns in MDA-MB-231 cells and its mammary fat pad tumor (TMD-231), lung-metastasis (LMD-231), bone-metastasis (BMD-231), adrenal-metastasis (ADMD-231) and brain-metastasis (231-BR) variants. When gene expression between metastases was compared, 231-BR cells showed the highest gene expression difference followed by ADMD-231, LMD-231, and BMD-231 cells. Neuronal transmembrane proteins SLITRK2, TMEM47, and LYPD1 were specifically overexpressed in 231-BR cells. Pathway-analyses revealed activation of signaling networks that would enable cancer cells to adapt to organs of metastasis such as drug detoxification/oxidative stress response/semaphorin neuronal pathway in 231-BR, Notch/orphan nuclear receptor signals involved in steroidogenesis in ADMD-231, acute phase response in LMD-231, and cytokine/hematopoietic stem cell signaling in BMD-231 cells. Only NF-κB signaling pathway activation was common to all except BMD-231 cells. We confirmed NF-κB activation in 231-BR and in a brain metastatic variant of 4T1 cells (4T1-BR). Dimethylaminoparthenolide inhibited NF-κB activity, LYPD1 expression, and proliferation of 231-BR and 4T1-BR cells. Thus, transcriptome change enabling adaptation to host organs is likely one of the mechanisms associated with organ-specific metastasis and could potentially be targeted therapeutically.
Prognosis of hormone-dependent breast cancers: implications of the presence of dysfunctional transcriptional networks activated by insulin via the immune transcription factor T-bet
(American Association for Cancer Research, 2010-01-15) McCune, Kasi; Bhat-Nakshatri, Poornima; Thorat, Mangesh A; Nephew, Kenneth P; Badve, Sunil; Nakshatri, Harikrishna
Estrogen receptor alpha (ERα)-positive breast cancers that co-express trans cription factors GATA-3 and FOXA1 have a favorable prognosis. These transcription factors form an autoregulatory hormonal network that influences estrogen responsiveness and sensitivity to hormonal therapy. Disruption of this network may be a mechanism whereby ERα positive breast cancers become resistant to therapy. The transcription factor T-bet is a negative regulator of GATA-3 in the immune system. In this study, we report that insulin increases the expression of T-bet in breast cancer cells, which correlates with reduced expression of GATA-3, FOXA1 and the ERα:FOXA1:GATA-3 target gene GREB-1. The effects of insulin on GATA-3 and FOXA1 could be recapitulated through overexpression of T-bet in MCF-7 cells (MCF-7-T-bet). Chromatin immunoprecipitation assays revealed reduced ERα binding to GREB-1 enhancer regions in MCF-7-T-bet cells and in insulin treated MCF-7 cells. MCF-7-T-bet cells were resistant to tamoxifen in the presence of insulin and displayed prolonged ERK and AKT activation in response to epidermal growth factor treatment. ERα-positive cells with intrinsic tamoxifen resistance as well as MCF-7 cells with acquired tamoxifen and fulvestrant resistance expressed elevated levels of T-bet and/or reduced levels of FOXA1 and GATA-3. Analysis of publicly available databases revealed ERα-positive/T-bet-positive breast cancers expressing lower levels of FOXA1 (p=0.0137) and GATA-3 (p=0.0063) compared to ERα-positive/T-bet-negative breast cancers. Thus, T-bet expression in primary tumors and circulating insulin levels may serve as surrogate biomarkers to identify ERα-positive breast cancers with a dysfunctional hormonal network, enhanced growth factor signaling, and resistance to hormonal therapy.

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