EWI2 prevents EGFR from clustering and endocytosis to reduce tumor cell movement and proliferation.

EWI2 is a transmembrane immunoglobulin superfamily (IgSF) protein that physically associates with tetraspanins and integrins. It inhibits cancer cells by influencing the interactions among membrane molecules including the tetraspanins and integrins. The present study revealed that, upon EWI2 silencing or ablation, the elevated movement and proliferation of cancer cells in vitro and increased cancer metastatic potential and malignancy in vivo are associated with (i) increases in clustering, endocytosis, and then activation of EGFR and (ii) enhancement of Erk MAP kinase signaling. These changes in signaling make cancer cells (i) undergo partial epithelial-to-mesenchymal (EMT) for more tumor progression and (ii) proliferate faster for better tumor formation. Inhibition of EGFR or Erk kinase can abrogate the cancer cell phenotypes resulting from EWI2 removal. Thus, to inhibit cancer cells, EWI2 prevents EGFR from clustering and endocytosis to restrain its activation and signaling.

Droplet digital PCR as an alternative to FISH for MYCN amplification detection in human neuroblastoma FFPE samples.

BACKGROUND: MYCN amplification directly correlates with the clinical course of neuroblastoma and poor patient survival, and serves as the most critical negative prognostic marker. Although fluorescence in situ hybridization (FISH) remains the gold standard for clinical diagnosis of MYCN status in neuroblastoma, its limitations warrant the identification of rapid, reliable, less technically challenging, and inexpensive alternate approaches. METHODS: In the present study, we examined the concordance of droplet digital PCR (ddPCR, in combination with immunohistochemistry, IHC) with FISH for MYCN detection in a panel of formalin-fixed paraffin-embedded (FFPE) human neuroblastoma samples. RESULTS: In 112 neuroblastoma cases, ddPCR analysis demonstrated a 96-100% concordance with FISH. Consistently, IHC grading revealed 92-100% concordance with FISH. Comparing ddPCR with IHC, we observed a concordance of 95-98%. CONCLUSIONS: The results demonstrate that MYCN amplification status in NB cases can be assessed with ddPCR, and suggest that ddPCR could be a technically less challenging method of detecting MYCN status in FFPE specimens. More importantly, these findings illustrate the concordance between FISH and ddPCR in the detection of MYCN status. Together, the results suggest that rapid, less technically demanding, and inexpensive ddPCR in conjunction with IHC could serve as an alternate approach to detect MYCN status in NB cases, with near-identical sensitivity to that of FISH.

Deciphering a GPCR-lncrna-miRNA nexus: Identification of an aberrant therapeutic target in ovarian cancer.

Ovarian cancer ranks as a leading cause of mortality among gynecological malignancies, primarily due to the lack of early diagnostic tools, effective targeted therapy, and clear understanding of disease etiology. Previous studies have identified the pivotal role of Lysophosphatidic acid (LPA)-signaling in ovarian cancer pathobiology. Our earlier transcriptomic analysis identified Urothelial Carcinoma Associated-1 (UCA1) as an LPA-stimulated long non-coding RNA (lncRNA). In this study, we elucidate the tripartite interaction between LPA-signaling, UCA1, and let-7 miRNAs in ovarian cancer progression. Results show that the elevated expression of UCA1 enhances cell proliferation, invasive migration, and therapy resistance in high-grade serous ovarian carcinoma cells, whereas silencing UCA1 reverses these oncogenic phenotypes. UCA1 expression inversely correlates with survival outcomes and therapy response in ovarian cancer clinical samples, underscoring its prognostic significance. Mechanistically, UCA1 sequesters let-7 miRNAs, effectively neutralizing their tumor-suppressive functions involving key oncogenes such as Ras and c-Myc. More significantly, intratumoral delivery of UCA1-specific siRNAs inhibits the growth of cisplatin-refractory ovarian cancer xenografts, demonstrating the therapeutic potential of targeting LPAR-UCA1-let-7 axis in ovarian cancer. Thus, our results identify LPAR-UCA1-let-7 axis as a novel avenue for targeted treatment strategies.

Targeting Oncometabolites in Peritoneal Cancers: Preclinical Insights and Therapeutic Strategies.

Peritoneal cancers present significant clinical challenges with poor prognosis. Understanding the role of cancer cell metabolism and cancer-promoting metabolites in peritoneal cancers can provide new insights into the mechanisms that drive tumor progression and can identify novel therapeutic targets and biomarkers for early detection, prognosis, and treatment response. Cancer cells dynamically reprogram their metabolism to facilitate tumor growth and overcome metabolic stress, with cancer-promoting metabolites such as kynurenines, lactate, and sphingosine-1-phosphate promoting cell proliferation, angiogenesis, and immune evasion. Targeting cancer-promoting metabolites could also lead to the development of effective combinatorial and adjuvant therapies involving metabolic inhibitors for the treatment of peritoneal cancers. With the observed metabolomic heterogeneity in cancer patients, defining peritoneal cancer metabolome and cancer-promoting metabolites holds great promise for improving outcomes for patients with peritoneal tumors and advancing the field of precision cancer medicine. This review provides an overview of the metabolic signatures of peritoneal cancer cells, explores the role of cancer-promoting metabolites as potential therapeutic targets, and discusses the implications for advancing precision cancer medicine in peritoneal cancers.

Optical Coherence Tomography of Tumor Spheroids Identifies Candidates for Drug Repurposing in Ovarian Cancer.

OBJECTIVE: Multicellular tumor spheroids (MCTs) are indispensable models for evaluating drug efficacy for precision cancer therapeutic strategies as well as for repurposing FDA-approved drugs for ovarian cancer. However, current imaging techniques cannot provide effective monitoring of pathological responses due to shallow penetration and experimentally operative destruction. We plan to utilize a noninvasive optical imaging tool to achieve in vivo longitudinal monitoring of the growth of MCTs and therapeutic responses to repurpose three FDA-approved drugs for ovarian cancer therapy. METHODS: A swept-source optical coherence tomography (SS-OCT) system was used to monitor the volume growth of MCTs over 11 days. Three inhibitors of 2-Methoxyestradiol (2-ME), AZD1208, and R-Ketorolac (R-keto) with concentrations of 1, 10, and 25 µM were employed to treat ovarian MCTs on day 5. Three-dimensional (3D), intrinsic optical attenuation contrast, and degree of uniformity were applied to analyze the therapeutic effect of these inhibitors on ovarian MCTs. RESULTS: We found that 2-ME, AZD1208, and R-keto with concentration of 10 and 25 µM significantly inhibited the volume growth of ovarian MCTs. There was no effect to necrotic tissues from all concentrations of 2-ME, AZD1208, and R-keto inhibitors from our OCT results. 2-ME and AZD1208 inhibited the growth of high uniformity tissues within MCTs and higher concentrations provided more significant inhibitory effects. CONCLUSION: Our results indicated that OCT was capable and reliable to monitor the therapeutic effect of inhibitors to ovarian MCTs and it can be used for the rapid characterization of novel therapeutics for ovarian cancers in the future.

Characterizing injury patterns and outcomes in hospitalized trauma patients with non-English Language Preferences.

INTRODUCTION: Patients with Non-English Language Preferences (NELP) experience challenges navigating the US healthcare system which can lead to disparate outcomes. This study sought to investigate injury patterns and outcomes in hospitalized trauma patients with NELP. METHODS: A retrospective review was performed at a trauma center from January 2019-December 2020. An institutional database of all emergency department video consultations for interpreter services was cross-referenced with the trauma registry and comparisons were made between NELP and English-preferred (EP) speaking patients. RESULTS: During the study, 257 NELP patients were hospitalized after traumatic injury. Twenty-two percent had work related injuries compared to only 3.0% in the EP cohort (p < 0.001). When propensity score matched, there were no significant differences in ICU and hospital length of stay or mortality between NELP and EP patients. DISCUSSION: Trauma patients are linguistically diverse and understanding their injury patterns and outcomes is crucial for guiding culturally and linguistically appropriate injury prevention.

Circulating Tumor Cell-Free DNA Genes as Prognostic Gene Signature for Platinum Resistant Ovarian Cancer Diagnosis.

Clinical management of gynecological cancer begins by optimal debulking with first-line platinum-based chemotherapy. However, in ~80% patients, ovarian cancer will recur and is lethal. Prognostic gene signature panel identifying platinum-resistance enables better patient stratification for precision therapy. Retrospectively collected serum from 11 "poor" (<6 months progression free interval [PFI]) and 22 "favorable" (>24 months PFI) prognosis patients, were evaluated using circulating cell-free DNA (cfDNA). DNA from both groups showed 50 to 10 000 bp fragments. Pairwise analysis of sequenced cfDNA from patients showed that gene dosages were higher for 29 genes and lower for 64 genes in poor than favorable prognosis patients. Gene ontology analysis of higher dose genes predominantly grouped into cytoskeletal proteins, while lower dose genes, as hydrolases and receptors. Higher dosage genes searched for cancer-relatedness in Reactome database indicated 15 genes were referenced with cancer. Among them 3 genes, TGFBR2, ZMIZ2, and NRG2, were interacting with more than 4 cancer-associated genes. Protein expression analysis of tumor samples indicated that TGFBR2 was downregulated and ZMIZ2 was upregulated in poor prognosis patients. Our results indicate that the cfDNA gene dosage combined with protein expression in tumor samples can serve as gene signature panel for prognosis determination amongst ovarian cancer patients.

An analysis of sexual dimorphism in the tumor microenvironment of colorectal cancer.

Women with colorectal cancer (CRC) have survival advantages over men, yet the underlying mechanisms are unclear. T cell infiltration within the CRC tumor microenvironment (TME) correlates strongly with survival. We hypothesized that women with CRC have increased T cell infiltration and differential gene expression in the TME compared to men. Tissue microarrays comprising primary tumor, tumor infiltrated lymph nodes, and uninvolved colon were created from CRC patients. Proportions of CD4 positive (CD4+) and CD8 positive (CD8+) T cells were identified using immunohistochemistry. TME immune- and cancer-related genetic expression from primary and metastatic CRC tumor were also evaluated via the NanoStringIO360 panel and The Cancer Genome Atlas Project database. CD4+ was higher in tumor samples from women compared to men (22.04% vs. 10.26%, p=0.002) and also in lymph node samples (39.54% vs. 8.56%, p=0.001). CD8+ was increased in uninvolved colon from women compared to men (59.40% vs. 43.61%, p=0.015), and in stage I/II tumors compared to III/IV in all patients (37.01% vs. 23.91%, p=0.009). Top CD8+ tertile patients survived longer compared to the bottom (43.9 months vs. 25.3 months, p=0.007). Differential gene expression was observed in pathways related to Treg function, T cell activity, and T cell exhaustion, amongst several others, in women compared to men. Thus, significant sexual dimorphism exists in the TME that could contribute to survival advantages observed in female patients with CRC.

Identification of GNA12-driven gene signatures and key signaling networks in ovarian cancer.

With the focus on defining the oncogenic network stimulated by lysophosphatidic acid (LPA) in ovarian cancer, the present study sought to interrogate the oncotranscriptome regulated by the LPA-mediated signaling pathway. LPA, LPA-receptor (LPAR) and LPAR-activated G protein 12 α-subunit, encoded by G protein subunit α 12 (GNA12), all serve an important role in ovarian cancer progression. While the general signaling mechanism regulated by LPA/LPAR/GNA12 has previously been characterized, the global transcriptomic network regulated by GNA12 in ovarian cancer pathophysiology remains largely unknown. To define the LPA/LPAR/GNA12-orchestrated oncogenic networks in ovarian cancer, transcriptomic and bioinformatical analyses were conducted using SKOV3 cells, in which the expression of GNA12 was silenced. Array analysis was performed in Agilent SurePrint G3 Human Comparative Genomic Hybridization 8×60 microarray platform. The array results were validated using Kuramochi cells. Gene and functional enrichment analyses were performed using Database for Annotation, Visualization and Integrated Discovery, Search Tool for Retrieval of Interacting Genes and Cytoscape algorithms. The results indicated a paradigm in which GNA12 drove ovarian cancer progression by upregulating a pro-tumorigenic network with AKT1, VEGFA, TGFB1, BCL2L1, STAT3, insulin-like growth factor 1 and growth hormone releasing hormone as critical hub and/or bottleneck nodes. Moreover, GNA12 downregulated a growth-suppressive network involving proteasome 20S subunit (PSM) ß6, PSM α6, PSM ATPase 5, ubiquitin conjugating enzyme E2 E1, PSM non-ATPase 10, NDUFA4 mitochondrial complex-associated, NADH:ubiquinone oxidoreductase subunit B8 and anaphase promoting complex subunit 1 as hub or bottleneck nodes. In addition to providing novel insights into the LPA/LPAR/GNA12-regulated oncogenic networks in ovarian cancer, the present study identified several potential nodes in this network that could be assessed for targeted therapy.

GNAi2/gip2-Regulated Transcriptome and Its Therapeutic Significance in Ovarian Cancer.

Increased expression of GNAi2, which encodes the α-subunit of G-protein i2, has been correlated with the late-stage progression of ovarian cancer. GNAi2, also referred to as the proto-oncogene gip2, transduces signals from lysophosphatidic acid (LPA)-activated LPA-receptors to oncogenic cellular responses in ovarian cancer cells. To identify the oncogenic program activated by gip2, we carried out micro-array-based transcriptomic and bioinformatic analyses using the ovarian cancer cell-line SKOV3, in which the expression of GNAi2/gip2 was silenced by specific shRNA. A cut-off value of 5-fold change in gene expression (p < 0.05) indicated that a total of 264 genes were dependent upon gip2-expression with 136 genes coding for functional proteins. Functional annotation of the transcriptome indicated the hitherto unknown role of gip2 in stimulating the expression of oncogenic/growth-promoting genes such as KDR/VEGFR2, CCL20, and VIP. The array results were further validated in a panel of High-Grade Serous Ovarian Carcinoma (HGSOC) cell lines that included Kuramochi, OVCAR3, and OVCAR8 cells. Gene set enrichment analyses using DAVID, STRING, and Cytoscape applications indicated the potential role of the gip2-stimulated transcriptomic network involved in the upregulation of cell proliferation, adhesion, migration, cellular metabolism, and therapy resistance. The results unravel a multi-modular network in which the hub and bottleneck nodes are defined by ACKR3/CXCR7, IL6, VEGFA, CYCS, COX5B, UQCRC1, UQCRFS1, and FYN. The identification of these genes as the critical nodes in GNAi2/gip2 orchestrated onco-transcriptome establishes their role in ovarian cancer pathophysiology. In addition, these results also point to these nodes as potential targets for novel therapeutic strategies.

Unraveling Autocrine Signaling Pathways through Metabolic Fingerprinting in Serous Ovarian Cancer Cells.

Focusing on defining metabolite-based inter-tumoral heterogeneity in ovarian cancer, we investigated the metabolic diversity of a panel of high-grade serous ovarian carcinoma (HGSOC) cell-lines using a metabolomics platform that interrogate 731 compounds. Metabolic fingerprinting followed by 2-dimensional and 3-dimensional principal component analysis established the heterogeneity of the HGSOC cells by clustering them into five distinct metabolic groups compared to the fallopian tube epithelial cell line control. An overall increase in the metabolites associated with aerobic glycolysis and phospholipid metabolism were observed in the majority of the cancer cells. A preponderant increase in the levels of metabolites involved in trans-sulphuration and glutathione synthesis was also observed. More significantly, subsets of HGSOC cells showed an increase in the levels of 5-Hydroxytryptamine, γ-aminobutyrate, or glutamate. Additionally, 5-hydroxytryptamin synthesis inhibitor as well as antagonists of γ-aminobutyrate and glutamate receptors prohibited the proliferation of HGSOC cells, pointing to their potential roles as oncometabolites and ligands for receptor-mediated autocrine signaling in cancer cells. Consistent with this role, 5-Hydroxytryptamine synthesis inhibitor as well as receptor antagonists of γ-aminobutyrate and Glutamate-receptors inhibited the proliferation of HGSOC cells. These antagonists also inhibited the three-dimensional spheroid growth of TYKNU cells, a representative HGSOC cell-line. These results identify 5-HT, GABA, and Glutamate as putative oncometabolites in ovarian cancer metabolic sub-type and point to them as therapeutic targets in a metabolomic fingerprinting-based therapeutic strategy.

G(alpha)12/13 inhibition enhances the anticancer effect of bortezomib through PSMB5 downregulation.

Bortezomib is a proteasome inhibitor approved for anticancer therapy. However, variable sensitivity of tumor cells exists in this therapy probably due to differences in the expression of proteasome subunits. G(alpha)(12/13) serves modulators or signal transducers in diverse pathways. This study investigated whether cancer cells display differential sensitivity to bortezomib with reference to G(alpha)(12/13) expression, and if so, whether G(alpha)(12/13) affects the expression of proteasome subunits and their activities. Bortezomib treatment exhibited greater sensitivities in Huh7 and SNU886 cells (epithelial type) than SK-Hep1 and SNU449 cells (mesenchymal type) that exhibited higher levels of G(alpha)(12/13). Overexpression of an active mutant of G(alpha)(12) (Galpha(12)QL) or G(alpha)(13) (G(alpha)(13)QL) diminished the ability of bortezomib to induce cytotoxicity in Huh7 cells. Moreover, transfection with the minigene that disturbs G protein-coupled receptor-G protein coupling (CT12 or CT13) increased it in SK-Hep1 cells. Consistently, MiaPaCa2 cells transfected with CT12 or CT13 exhibited a greater sensitivity to bortezomib. Evidence of G(alpha)(12/13)'s antagonism on the anticancer effect of bortezomib was verified in the reversal by G(alpha)(12)QL or G(alpha)(13)QL of the minigenes' enhancement of cytotoxity. Real-time polymerase chain reaction assay enabled us to identify PSMB5, multicatalytic endopeptidase complex-like-1, and proteasome activator subunit-1 repression by CT12 or CT13. Furthermore, G(alpha)(12/13) inhibition enhanced the ability of bortezomib to repress PSMB5, as shown by immunoblotting and proteasome activity assay. Moreover, this inhibitory effect on PSMB5 was attenuated by G(alpha)G(alpha)(12)QL or G(alpha)(13)QL. In conclusion, the inhibition of G(alpha)(12/13) activities may enhance the anticancer effect of bortezomib through PSMB5 repression, providing insight into the G(alpha)(12/13) pathway for the regulation of proteasomal activity.

R9AP and R7BP: traffic cops for the RGS7 family in phototransduction and neuronal GPCR signaling.

RGS (regulator of G protein signaling) proteins have emerged as crucial regulators, effectors and integrators in G-protein-coupled receptor (GPCR) signaling networks. Many RGS proteins accelerate GTP hydrolysis by Galpha subunits, thereby regulating G protein activity, whereas certain RGS proteins also transduce Galpha signals to downstream targets. Particularly intriguing are members of the RGS7 (R7) family (RGS6, RGS7, RGS9 and RGS11), which heterodimerize with Gbeta5. In Caenorhabditis elegans, R7-Gbeta5 heterodimers regulate synaptic transmission, anesthetic action and behavior. In vertebrates, they regulate vision, postnatal development, working memory and the action of psychostimulants or morphine. Here we highlight R9AP and R7BP, a related pair of recently identified SNARE-like R7-family binding proteins, which regulate intracellular trafficking, expression and function of R7-Gbeta5 heterodimers in retina and brain. Emerging understanding of R7BP and R9AP promises to provide new insights into neuronal GPCR signaling mechanisms relevant to the causes and treatment of neurological disorders.

Chemopreventive and Anticancer Effects of Thymoquinone: Cellular and Molecular Targets.

Thymoquinone (TQ) is a bioactive component derived from the seeds of Nigella sativa that are commonly as black cumin. Evidences indicate that the medicinal properties of TQ have been recognized for more than 2000 years. TQ has been shown to possess potent chemopreventive properties that include anti-inflammatory and anti-neoplastic activities. Recent studies have unraveled the multiple mechanisms through which TQ exerts its chemopreventive and anticancer activity in different cancer cells in a contextual manner. The present review aims to provide a brief compendium on the molecular mechanisms through which TQ inhibits signaling pathways underlying cancer genesis, progression, and metastasis.

Differential effects of thymoquinone on lysophosphatidic acid-induced oncogenic pathways in ovarian cancer cells.

Thymoquinone, a therapeutic phytochemical derived from Nigella sativa, has been shown to have a potent anticancer activity. However, it has been identified that the tumor microenvironment (TME) can attenuate the anticancer effects of thymoquinone (TQ) in ovarian cancer. Lysophosphatidic acid (LPA), a lipid growth factor present in high concentration in the TME of ovarian cancer, has been shown to regulate multiple oncogenic pathways in ovarian cancer. Taking account of the crucial role of LPA in the genesis and progression of ovarian cancer, the present study is focused on assessing the efficacy of TQ in inhibiting LPA-stimulated oncogenic pathways in ovarian cancer cells. Our results indicate that TQ is unable to attenuate LPA-stimulated proliferation or metabolic reprogramming in ovarian cancer cells. However, TQ potently inhibits the basal as well as LPA-stimulated migratory responses of the ovarian cancer cells. Furthermore, TQ abrogates the invasive migration of ovarian cancer cells induced by Gαi2, through which LPA stimulates cell migration. TQ also attenuates the activation of JNK, Src, and FAK, the downstream signaling nodes of LPA-LPAR-Gαi2 signaling pathway. In addition to establishing the differential effects of TQ in ovarian cancer cells, our results unravel the antitherapeutic role of LPA in the ovarian cancer TME could override the inhibitory effects of TQ on cell proliferation and metabolic reprogramming of ovarian cancer cells. More importantly, the concomitant finding that TQ could still sustain its inhibitory effect on LPA-stimulated invasive cell migration, points to its potential use as a response-specific therapeutic agent in ovarian cancer.

Ovarian cancer cell-derived lysophosphatidic acid induces glycolytic shift and cancer-associated fibroblast-phenotype in normal and peritumoral fibroblasts.

Cancer-associated fibroblasts (CAFs) play a critical role in cancer progression, metastasis, and therapy resistance. Molecular events that confer CAF-phenotype to predecessor-cells are not fully understood. We demonstrate here that the ovarian cancer cell-conditioned medium (OCC-CM) induces CAF-phenotype in MRC5 lung-fibroblasts and it can be mimicked by LPA. While OCC-CM and LPA stimulated the expression of cellular CAF-markers by 3-days, they induced aerobic glycolysis, a metabolic marker for CAF, by 6 hrs. OCC-CM/LPA-induced glycolysis in lung (MRC5) as well as ovarian fibroblasts (NOF151) was inhibited by the LPA-receptor antagonist, Ki16425. Ovarian cancer patient-derived ascitic fluid-induced aerobic glycolysis in both NFs and Ovarian CAFs and it was inhibited by Ki16425. Further analysis indicated that LPA upregulated HIF1α-levels and the silencing of HIF1α attenuated LPA-induced glycolysis in both NOFs and CAFs. These results establish LPA-induced glycolytic-shift as the earliest, potentially priming event, in NF to CAF-transition. These findings also identify a role for LPA-LPAR-HIF1α signaling-hub in the maintenance of the glycolytic-phenotype in CAFs. Our results provide evidence that targeted inhibition of LPA-mediated metabolic reprogramming in CAFs may represent an adjuvant therapy in ovarian cancer.

LPA Induces Metabolic Reprogramming in Ovarian Cancer via a Pseudohypoxic Response.

Although hypoxia has been shown to reprogram cancer cells toward glycolytic shift, the identity of extrinsic stimuli that induce metabolic reprogramming independent of hypoxia, especially in ovarian cancer, is largely unknown. In this study, we use patient-derived ovarian cancer cells and high-grade serous ovarian cancer cell lines to demonstrate that lysophosphatidic acid (LPA), a lipid growth factor and GPCR ligand whose levels are substantially increased in ovarian cancer patients, triggers glycolytic shift in ovarian cancer cells. Inhibition of the G protein α-subunit Gαi2 disrupted LPA-stimulated aerobic glycolysis. LPA stimulated a pseudohypoxic response via Rac-mediated activation of NADPH oxidase and generation of reactive oxygen species, resulting in activation of HIF1α. HIF1α in turn induced expression of glucose transporter-1 and the glycolytic enzyme hexokinase-2 (HKII). Treatment of mice bearing ovarian cancer xenografts with an HKII inhibitor, 3-bromopyruvate, attenuated tumor growth and conferred a concomitant survival advantage. These studies reveal a critical role for LPA in metabolic reprogramming of ovarian cancer cells and identify this node as a promising therapeutic target in ovarian cancer.Significance: These findings establish LPA as a potential therapeutic target in ovarian cancer, revealing its role in the activation of HIF1α-mediated metabolic reprogramming in this disease. Cancer Res; 78(8); 1923-34. ©2018 AACR.

Transition from androgenic to neurosteroidal action of 5α-androstane-3α, 17ß-diol through the type A γ-aminobutyric acid receptor in prostate cancer progression.

Androgen ablation is the standard of care prescribed to patients with advanced or metastatic prostate cancer (PCa) to slow down disease progression. Unfortunately, a majority of PCa patients under androgen ablation progress to castration-resistant prostate cancer (CRPC). Several mechanisms including alternative intra-prostatic androgen production and androgen-independent androgen receptor (AR) activation have been proposed for CRPC progression. Aldo-keto reductase family 1 member C3 (AKR1C3), a multi-functional steroid metabolizing enzyme, is specifically expressed in the cytoplasm of PCa cells; and positive immunoreactivity of the type A γ-aminobutyric acid receptor (GABAAR), an ionotropic receptor and ligand-gated ion channel, is detected on the membrane of PCa cells. We studied a total of 72 radical prostatectomy cases by immunohistochemistry, and identified that 21 cases exhibited positive immunoreactivities for both AKR1C3 and GABAAR. In the dual positive cancer cases, AKR1C3 and GABAAR subunit α1 were either expressed in the same cells or in neighboring cells. Among several possible substrates, AKR1C3 reduces 5α-dihydrotesterone (DHT) to form 5α-androstane-3α, 17ß-diol (3α-diol). 3α-diol is a neurosteroid that acts as a positive allosteric modulator of the GABAAR in the central nervous system (CNS). We examined the hypothesis that 3α-diol-regulated pathological effects in the prostate are GABAAR-dependent, but are independent of the AR. In GABAAR-positive, AR-negative human PCa PC-3 cells, 3α-diol significantly stimulated cell growth in culture and the in ovo chorioallantoic membrane (CAM) xenograft model. 3α-diol also up-regulated expression of the epidermal growth factor (EGF) family of growth factors and activation of EGF receptor (EGFR) and Src as measured by quantitative polymerase chain reaction and immunoblotting, respectively. Inclusion of GABAAR antagonists reversed 3α-diol-stimulated tumor cell growth, expression of EGF family members, and activation of EGFR and Src to the level observed in untreated cells. Results from the present study suggest that 3α-diol may act as an alternative intra-prostatic neurosteroid that activates AR-independent PCa progression. The involvement of AKR1C3-mediated steroid metabolisms in modulating GABAAR activation and promoting PCa progression requires continued studies.

Identification of novel diagnostic and prognostic miRNA signatures in endometrial cancer.

With the goal of identifying diagnostic and prognostic biomarkers in endometrial cancer, miRNA-profiling was carried out with formalin-fixed paraffin embedded (FFPE) tissue samples from 49 endometrial cancer patients. Results using an 84-cancer specific miRNA panel identified the upregulation of miR-141-3p and miR-96-5p along with a downregulation of miR-26, miR-126-3p, miR-23b, miR-195-5p, miR-374a and let-7 family of miRNAs in endometrial cancer. We validated the dysregulated expression of the identified miRNAs in a panel of endometrial cancer cell-lines. Immunohistochemical analysis of the tissue micro array derived from these patients established the functional correlation between the decreased expression of tumor suppressive miRNAs and their target oncogenes: ERBB2, EGFR, EPHA2, BAX, GNA12, GNA13, and JUN. Comparative analysis of the samples from the patients with extended progression-free survival (PFS) ( > 21 months) versus the patients with the PFS of < 21 months indicated increased expression of tumor suppressive miR-142-3p, miR-142-5p, and miR-15a-5p in samples from extended PFS patients. In addition to defining a specific set of miRNAs and their target genes as potential diagnostic biomarkers, our studies have identified tumor suppressive miR-142 cluster and miR-15a as predictors of favorable prognosis for therapy response in endometrial cancer.

MICU1 drives glycolysis and chemoresistance in ovarian cancer.

Cancer cells actively promote aerobic glycolysis to sustain their metabolic requirements through mechanisms not always clear. Here, we demonstrate that the gatekeeper of mitochondrial Ca2+ uptake, Mitochondrial Calcium Uptake 1 (MICU1/CBARA1) drives aerobic glycolysis in ovarian cancer. We show that MICU1 is overexpressed in a panel of ovarian cancer cell lines and that MICU1 overexpression correlates with poor overall survival (OS). Silencing MICU1 in vitro increases oxygen consumption, decreases lactate production, inhibits clonal growth, migration and invasion of ovarian cancer cells, whereas silencing in vivo inhibits tumour growth, increases cisplatin efficacy and OS. Mechanistically, silencing MICU1 activates pyruvate dehydrogenase (PDH) by stimulating the PDPhosphatase-phosphoPDH-PDH axis. Forced-expression of MICU1 in normal cells phenocopies the metabolic aberrations of malignant cells. Consistent with the in vitro and in vivo findings we observe a significant correlation between MICU1 and pPDH (inactive form of PDH) expression with poor prognosis. Thus, MICU1 could serve as an important therapeutic target to normalize metabolic aberrations responsible for poor prognosis in ovarian cancer.