DACH1 mutation frequency in endometrial cancer is associated with high tumor mutation burden in a nationwide cohort

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Background: DACH1 is a novel transcriptional repressor and tumor suppressor gene. DACH1 mutations are associated with poor prognostic features and reduced overall survival in endometrial cancer, with an increased prevalence in the Appalachian region of Kentucky. Preliminary studies have suggested an association with an increase in tumor mutation burden. In this follow up study, we utilized the nationwide Oncology Research Information Exchange Network (ORIEN) to determine the frequency of DACH1 mutations in patients with endometrial cancer through a multi-institution analysis and evaluate its impact on RNA expression, clinical correlates, and outcomes. Methods: We obtained clinical and genomic data for 691 patients with endometrial cancer from nine U.S. institutions within the ORIEN collaborative. We examined the clinical attributes of the cancers with DACH1 status by comparing whole-exome sequencing (WES), RNA Sequencing (RNASeq), microsatellite instability (MSI), and tumor mutational burden (TMB). Results: Appalachian women with endometrial cancer had an increased frequency of DACH1 mutations (6/41 patients, 15%) compared to the non-Appalachian endometrial cancer population (24/581 patients, 4.1%) with p-value = 0.010, with the non-Appalachian DACH1 mutation frequency mirroring the rate of DACH1 gene mutation seen in TCGA at 3.8%. DACH1 mutated patients have a higher tumor mutation burden compared to DACH1 wild-type (32.2 vs. 4.62, p-value = 0.001) though no differences in microsatellite instability between DACH1 mutated and wild-type were present (p-value = 0.350). DACH1 mutations showed significant gene co-occurrence patterns with POLE, MLH1, MSH2, MSH6 and PMS2. Conclusions: DACH1 mutations are prevalent in Kentucky patients with endometrial cancer, particularly those from the Appalachian region. These results were again reflected in the TCGA PanCancer Atlas as well as the ORIEN multi-institution cohort. These mutations are associated with high tumor mutational burden and co-occur with genome destabilizing gene mutations. These findings suggest DACH1 as a candidate biomarker for future trials with immunotherapy, particularly in endometrial cancers.

Combined VEGFR and MAPK pathway inhibition in angiosarcoma

Angiosarcoma is an aggressive malignancy of endothelial cells that carries a high mortality rate. Cytotoxic chemotherapy can elicit clinical responses, but the duration of response is limited. Sequencing reveals multiple mutations in angiogenesis pathways in angiosarcomas, particularly in vascular endothelial growth factor (VEGFR) and mitogen-activated protein kinase (MAPK) signaling. We aimed to determine the biological relevance of these pathways in angiosarcoma. Tissue microarray consisting of clinical formalin-fixed paraffin embedded tissue archival samples were stained for phospho- extracellular signal-regulated kinase (p-ERK) with immunohistochemistry. Angiosarcoma cell lines were treated with the mitogen-activated protein kinase kinase (MEK) inhibitor trametinib, pan-VEGFR inhibitor cediranib, or combined trametinib and cediranib and viability was assessed. Reverse phase protein array (RPPA) was performed to assess multiple oncogenic protein pathways. SVR angiosarcoma cells were grown in vivo and gene expression effects of treatment were assessed with whole exome RNA sequencing. MAPK signaling was found active in over half of clinical angiosarcoma samples. Inhibition of MAPK signaling with the MEK inhibitor trametinib decreased the viability of angiosarcoma cells. Combined inhibition of the VEGF and MAPK pathways with cediranib and trametinib had an additive effect in in vitro models, and a combinatorial effect in an in vivo model. Combined treatment led to smaller tumors than treatment with either agent alone. RNA-seq demonstrated distinct expression signatures between the trametinib treated tumors and those treated with both trametinib and cediranib. These results indicate a clinical study of combined VEGFR and MEK inhibition in angiosarcoma is warranted.

Tumor core biopsies adequately represent immune microenvironment of high-grade serous carcinoma

The prognostic and therapeutic value of the tumor microenvironment (TME) in various cancer types is of major interest. Characterization of the TME often relies on a small representative tissue sample. However, the adequacy of such a sample for assessing components of the TME is not yet known. Here, we used immunohistochemical (IHC) staining and 7-color multiplex staining to evaluate CD8 (cluster of differentiation 8), CD68, PD-L1 (programmed death-ligand 1), CD34, FAP (fibroblast activation protein), and cytokeratin in 220 tissue cores from 26 high-grade serous ovarian cancer samples. Comparisons were drawn between a larger tumor specimen and smaller core biopsies based on number and location (central tumor vs. peripheral tumor) of biopsies. Our analysis found that the correlation between marker-specific cell subsets in larger tumor versus smaller core was stronger with two core biopsies and was not further strengthened with additional biopsies. Moreover, this correlation was consistently strong regardless of whether the biopsy was taken at the center or at the periphery of the original tumor sample. These findings could have a substantial impact on longitudinal assessment for detection of biomarkers in clinical trials.

Sustained Adrenergic Signaling Promotes Intratumoral Innervation through BDNF Induction

Mounting clinical and preclinical evidence supports a key role for sustained adrenergic signaling in the tumor microenvironment as a driver of tumor growth and progression. However, the mechanisms by which adrenergic neurotransmitters are delivered to the tumor microenvironment are not well understood. Here we present evidence for a feed-forward loop whereby adrenergic signaling leads to increased tumoral innervation. In response to catecholamines, tumor cells produced brain-derived neurotrophic factor (BDNF) in an ADRB3/cAMP/Epac/JNK-dependent manner. Elevated BDNF levels in the tumor microenvironment increased innervation by signaling through host neurotrophic receptor tyrosine kinase 2 receptors. In patients with cancer, high tumor nerve counts were significantly associated with increased BDNF and norepinephrine levels and decreased overall survival. Collectively, these data describe a novel pathway for tumor innervation, with resultant biological and clinical implications.Significance: Sustained adrenergic signaling promotes tumor growth and metastasis through BDNF-mediated tumoral innervation. Cancer Res; 78(12); 3233-42. ©2018 AACR.

Inhibiting Nuclear Phospho-Progesterone Receptor Enhances Antitumor Activity of Onapristone in Uterine Cancer

Although progesterone receptor (PR)-targeted therapies are modestly active in patients with uterine cancer, their underlying molecular mechanisms are not well understood. The clinical use of such therapies is limited because of the lack of biomarkers that predict response to PR agonists (progestins) or PR antagonists (onapristone). Thus, understanding the underlying molecular mechanisms of action will provide an advance in developing novel combination therapies for cancer patients. Nuclear translocation of PR has been reported to be ligand-dependent or -independent. Here, we identified that onapristone, a PR antagonist, inhibited nuclear translocation of ligand-dependent or -independent (EGF) phospho-PR (S294), whereas trametinib inhibited nuclear translocation of EGF-induced phospho-PR (S294). Using orthotopic mouse models of uterine cancer, we demonstrated that the combination of onapristone and trametinib results in superior antitumor effects in uterine cancer models compared with either monotherapy. These synergistic effects are, in part, mediated through inhibiting the nuclear translocation of EGF-induced PR phosphorylation in uterine cancer cells. Targeting MAPK-dependent PR activation with onapristone and trametinib significantly inhibited tumor growth in preclinical uterine cancer models and is worthy of further clinical investigation. Mol Cancer Ther; 17(2); 464-73. ©2017 AACR.

When advanced ovarian cancer is not ovarian cancer

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Background:Tissue diagnosis of advanced ovarian cancer (OC) is not universally obtained prior to up-front surgery. This study sought to investigate non-OC cases discovered in the systemic laparoscopic (LSC) workup of presumed advanced OC. Methods: A prospective cohort of presumed advanced OC patients (based on elevated CA125 and/or imaging) presenting to our center without confirmed pathologic diagnosis. Patients with non-OC pathology confirmed in workup were characterized and compared to those with confirmed ovarian pathology using standard statistical tests. Results: 365 patients presented between 5/30/12 and 11/16/16. Non-OC was found in 27 cases (7.4%), including benign ovarian pathology (48%), and metastatic uterine (11%), breast (7%) and gastrointestinal (19%) cancers. A majority used diagnostic LSC or assessment at time of up-front surgery (see Table) for diagnosis. Non-OC cases were less likely to be confirmed by FNA or core biopsy, were more common in Asian patients, had better ECOG scores, and had a lower CA125. Only 1 non-OC patient (uterine sarcoma) received neo-adjuvant chemotherapy. Conclusions: A systematic LSC approach to advanced stage OC minimizes incorrect chemotherapy chemotherapy administration. Asian patients and those with low CA125 values are at highest risk of a false diagnosis of OC, but did not routinely have a diagnostic opportunity prior to systematic LSC. [Table: see text]