Mateusz Opyrchal

CXCL12/CXCR4 Blockade by Oncolytic Virotherapy Inhibits Ovarian Cancer Growth by Decreasing Immunosuppression and Targeting Cancer-Initiating Cells

Signals mediated by the chemokine CXCL12 and its receptor CXCR4 are involved in the progression of ovarian cancer through enhancement of tumor angiogenesis and immunosuppressive networks that regulate dissemination of peritoneal metastasis and development of cancer-initiating cells (CICs). In this study, we investigated the antitumor efficacy of a CXCR4 antagonist expressed by oncolytic vaccinia virus (OVV) against an invasive variant of the murine epithelial ovarian cancer cell line ID8-T. This variant harbors a high frequency of CICs that form multilayered spheroid cells and express the hyaluronan receptor CD44, as well as stem cell factor receptor CD117 (c-kit). Using an orthotopic ID8-T tumor model, we observed that i.p. delivery of a CXCR4 antagonist–expressing OVV led to reduced metastatic spread of tumors and improved overall survival compared with oncolysis alone. Inhibition of tumor growth with the armed virus was associated with efficient killing of CICs, reduced expression of ascitic CXCL12 and vascular endothelial growth factor, and decreases in i.p. numbers of endothelial and myeloid cells, as well as plasmacytoid dendritic cells. These changes, together with reduced recruitment of T regulatory cells, were associated with higher ratios of IFN-γ+/IL-10+ tumor-infiltrating T lymphocytes, as well as induction of spontaneous humoral and cellular antitumor responses. Similarly, the CXCR4 antagonist released from virally infected human CAOV2 ovarian carcinoma cells inhibited peritoneal dissemination of tumors in SCID mice, leading to improved tumor-free survival in a xenograft model. Our findings demonstrate that OVV armed with a CXCR4 antagonist represents a potent therapy for ovarian CICs with a broad antitumor repertoire.

Comprehensive Histologic Scoring to Maximize the Predictability of Pathology-generated Equation of Breast Cancer Oncotype DX Recurrence Score.

Background:Pathology-generated equations have been introduced to predict Oncotype DX recurrence score (ORS) in breast cancer. The purpose of the study is to improve these equations. Materials and Methods:Slides from 416 (test set) consecutive breast cancers with available Oncotype DX were reviewed. A validation set (n=91) was prospectively scored using the generated formulas from the test set. The following histopathologic features were graded: Nottingham grade (designated as current Nottingham grade), necrosis, and degree of tumor-infiltrating lymphocytes. The following data were extracted from the pathology report: Nottingham grade (designated as reported Nottingham grade), tumor size, ER/PR Allred scores, HER2 status, and ORS. Equations were calculated, one included the reported Nottingham grade, one included the current Nottingham grade, and one included the current Nottingham grade with the other significant histopathologic variables. Results:In the equation that included the reported Nottingham grade, ER, PR, and HER2, the overall concordance with the ORS was 64.86%. After excluding the intermediate category detected by the formula, the concordance rate was 95.28%. When the current Nottingham grade was included, the concordance rate became 69.61% and 98.62%, respectively. When necrosis and the degree of tumor-infiltrating lymphocytes were added to the previous equation, these rates became 70.1% and 98.63%, respectively. Conclusions:Our equation has better correlation with ORS than previously published results.

Clinical Trials with Oncolytic Measles Virus: Current Status and Future Prospects

Attenuated Edmonston lineage measles virus (MV-Edm) vaccine strains can preferentially infect and lyse a wide variety of cancer cells. Oncolytic MV-Edm derivatives are genetically engineered to express the human carcinoembryonic antigen (MV-CEA virus) or the human sodium iodide symporter (MV-NIS virus) and are currently being tested in clinical trials against ovarian cancer, glioblastoma multiforme, multiple myeloma, mesothelioma, head and neck cancer, breast cancer and malignant peripheral nerve sheath tumors. This review describes the basic and preclinical data that facilitated the clinical translation of MV-Edm strains, and summarizes the clinical results of this oncolytic platform to date. Furthermore, we discuss the latest clinically relevant MV-Edm vector developments and creative strategies for future translational steps.

Reprogramming antitumor immunity against chemoresistant ovarian cancer by a CXCR4 antagonist-armed viral oncotherapy

Ovarian cancer remains the most lethal gynecologic malignancy owing to late detection, intrinsic and acquired chemoresistance, and remarkable heterogeneity. Here, we explored approaches to inhibit metastatic growth of murine and human ovarian tumor variants resistant to paclitaxel and carboplatin by oncolytic vaccinia virus expressing a CXCR4 antagonist to target the CXCL12 chemokine/CXCR4 receptor signaling axis alone or in combination with doxorubicin. The resistant variants exhibited augmented expression of the hyaluronan receptor CD44 and CXCR4 along with elevated Akt and ERK1/2 activation and displayed an increased susceptibility to viral infection compared with the parental counterparts. The infected cultures were more sensitive to doxorubicin-mediated killing both in vitro and in tumor-challenged mice. Mechanistically, the combination treatment increased apoptosis and phagocytosis of tumor material by dendritic cells associated with induction of antitumor immunity. Targeting syngeneic tumors with this regimen increased intratumoral infiltration of antitumor CD8+ T cells. This was further enhanced by reducing the immunosuppressive network by the virally-delivered CXCR4 antagonist, which augmented antitumor immune responses and led to tumor-free survival. Our results define novel strategies for treatment of drug-resistant ovarian cancer that increase immunogenic cell death and reverse the immunosuppressive tumor microenvironment, culminating in antitumor immune responses that control metastatic tumor growth.

Molecular targeting of the Aurora-A/SMAD5 oncogenic axis restores chemosensitivity in human breast cancer cells

Although the majority of breast cancers initially respond to the cytotoxic effects of chemotherapeutic agents, most breast cancer patients experience tumor relapse and ultimately die because of drug resistance. Breast cancer cells undergoing epithelial to mesenchymal transition (EMT) acquire a CD44+/CD24-/ALDH1+ cancer stem cell-like phenotype characterized by an increased capacity for tumor self-renewal, intrinsic drug resistance and high proclivity to develop distant metastases. We uncovered in human breast tumor xenografts a novel non-mitotic role of Aurora-A kinase in promoting breast cancer metastases through activation of EMT and expansion of breast tumor initiating cells (BTICs). In this study we characterized the role of the Aurora-A/SMAD5 oncogenic axis in the induction of chemoresistance. Breast cancer cells overexpressing Aurora-A showed resistance to conventional chemotherapeutic agents, while treatment with alisertib, a selective Aurora-A kinase inhibitor, restored chemosensitivity. Significantly, SMAD5 expression was required to induce chemoresistance and maintain a breast cancer stem cell-like phenotype, indicating that the Aurora-A/SMAD5 oncogenic axis promotes chemoresistance through activation of stemness signaling. Taken together, these findings identified a novel mechanism of drug resistance through aberrant activation of the non-canonical Aurora-A/SMAD5 oncogenic axis in breast cancer.

A Rare Case of S310F Somatic ERBB2 Mutation in a HER2-Nonamplified Breast Cancer

Amplification of the epidermal growth factor 2 (ERBB2) gene, encoding the human epidermal growth factor receptor 2 (HER2), has been implicated in several different malignancies, including breast cancer. More recently, research has indicated that a proportion of non-ERBB2 amplified breast cancers can harbor activating somatic mutations that render them susceptible to anti-HER2 agents. We present here a unique case of a patient with metastatic hormone receptorepositive, ERBB2-not amplified breast cancer, with a S310F activating mutation who responded to treatment with trastuzumab. This case highlights the increasing importance of genomic testing patients with nonamplified ERBB2 breast cancers.

Prognostic Significance of Stromal Versus Intratumoral Infiltrating Lymphocytes in Different Subtypes of Breast Cancer Treated With Cytotoxic Neoadjuvant Chemotherapy.

Background: The aim of the study was to investigate if there were differences in associations of stromal versus intratumoral tumor infiltrating lymphocytes (TILs) with pathology complete response (pCR) among breast cancer (BC) subtypes treated with neoadjuvant therapy. Materials and Methods: The hematoxylin and eosin slides of BC-core biopsy consecutive cases (n=331) were reviewed from a single institution between 2000 and 2014. TIL-stroma (TIL-str) was scored from 0% to 100%. Intratumoral lymphocytes (iTu-Ly) were scored semiquantitatively incorporating the infiltrate grade (0 to 3) and the corresponding percentage resulting in a score ranging from 0 to 300. pCR was defined as no residual infiltrating tumor in the tumor bed and the lymph nodes. Results: pCR was achieved in 29 of 95 (30.9%) triple negative cases, 25 of 77 (32.5%) HER2+, and 9 of 159 (5.6%) luminal tumors. In univariate analysis, invasive nonlobular carcinoma, higher Nottingham grade, nonluminal subtypes, trastuzumab therapy, nonadvanced clinical T stage (T1 and T2), TIL-str, and iTu-Ly-predicted pCR. In luminal subtype, iTu-Ly but not TIL-str was an independent predictor for pCR [odds ratio (OR)=1.44, 95% confidence interval (CI), 1.08-1.9, P=0.013]. In triple negative subtype, both TIL-str and iTu-Ly were independent predictors for pCR (OR=1.68, 95% CI, 1.29-2.18, P=0.001; OR=1.31, 95% CI, 1.05-1.63, P=0.017, respectively). In HER2+ subtype, neither TIL-str nor iTu-Ly predicted pCR. Conclusions: TILs are variably correlated with better neoadjuvant chemotherapy response depending on their location and clinical subtype of BC. It could indicate that TILs might be functionally heterogeneous with regard to their role in mediating antitumor immune response, depending on their location and BC subtypes.

A Case of Metaplastic Breast Cancer with Prolonged Response to Single Agent Liposomal Doxorubicin

Female breast cancer accounts for 14% of all new cancer cases in the United States. Metaplastic breast carcinomas (MpBC) are less than 1% of all mammary tumors. Limited clinical information exists on the prognosis and treatments for MpBC due to its rarity and the histological diversity of the tumor cells. We report a case of metastatic MpBC with osseous differentiation who had a marked response to liposomal doxorubicin. This 54-year-old female presented with a 2.5 x 2.6 cm oval-shaped irregularly marginated density in the outer lower quadrant of the left breast, cT2N0M0. Biopsy revealed an invasive metaplastic carcinoma, triple negative, with osseous and focal chondroid differentiation. Genetic testing showed a mutation in the BRCA1 gene. Approximately seven months after a left mastectomy, the patient presented with biopsy-proven metastatic disease and was initiated on therapy with a single agent, liposomal doxorubicin, 50 mg/m2 every 28 days. The patient achieved maximum response after cycle three and continued to have stable disease for 18 months (20 cycles). Based on the pathologic phenotype, we would have predicted that she would have had a poor and short response to anthracycline. This case illustrates an increased sensitivity of BRCA1-mutated cancers to anthracycline therapies, irrespective of pathologic classification.

Exceptional Clinical Response to BRAF-Targeted Therapy in a Patient with Metastatic Sarcoma

Soft tissue sarcomas (STS) are a rare and heterogeneous group of tumors arising from mesenchymal tissue comprising 1% of all adult cancers. The prognosis of metastatic STS is dismal. As there are few active drugs, there is a critical need to find new therapeutic alternatives in order to improve outcomes. Most sarcoma subtypes are fairly resistant to standard chemotherapy regimens and/or have a short duration of response. The era of molecular targeted therapy may present new treatment options for metastatic STS and an opportunity to drive biomarker discovery and personalized medicine. This case report describes a patient with a synchronous metastatic high-grade sarcoma who was treated with BRAF-targeted therapy with resolution of his metastatic lesions. To our knowledge, this exceptional response has not been described in sarcoma literature. The patient presented with a large anterior abdominopelvic wall mass. Biopsy showed a high-grade spindle cell sarcoma. Staging scans confirmed two pulmonary metastases. He was initiated on combination chemotherapy with mixed results. He received 50 Gy of radiation to the primary tumor followed by two additional cycles of combination chemotherapy, with an interval increase in the size of the pulmonary metastases. Molecular testing revealed a BRAF V600E mutation in the primary tumor. The patient was initiated on dabrafenib/trametinib with a dramatic response and resolution of his pulmonary metastases. The patient underwent surgical resection of his primary mass, and pathology confirmed no evidence of residual disease. Detailed genetic characterization of STS coupled with novel therapeutic strategies, including molecular targeted therapy, may have the potential to transform the care of patients diagnosed with sarcoma.

Efficacy of Palbociclib Combinations in Hormone Receptor–Positive Metastatic Breast Cancer Patients After Prior Everolimus Treatment

Purpose: Outcome data on hormone receptor positive (HR+), human epidermal growth factor receptor 2 (HER2) nonamplified (HER2−) metastatic breast cancer (MBC) treated with palbociclib after treatment with everolimus are lacking. The PALOMA‐3 trial, showing benefit of palbociclib plus fulvestrant compared to fulvestrant alone in HR+HER2− MBC after progression while receiving endocrine therapy excluded women previously treated with everolimus. The objective of this study was to examine outcomes of HR+HER2− MBC with prior exposure to everolimus while receiving palbociclib‐based therapy. Patients and Methods: A retrospective, single‐institute review was conducted of HR+HER2− MBC from January 2014 to November 2016 in patients treated with palbociclib after prior treatment with everolimus. Progression‐free survival (PFS) was defined as the time from initiation of palbociclib to the date of progression as determined by the treating physician based on radiologic, biochemical, and/or clinical criteria. Response rates were determined on the basis of available radiologic data. Objective response rate (ORR) was defined as the rate of any complete or partial responses; clinical benefit rate (CBR) was the rate of complete response, partial response, or stable disease for at least 24 weeks. Results: Twenty‐three patients with a mean (range) age of 68 (42‐81) years were identified. Kaplan‐Meier estimate showed median PFS of 2.9 months (95% confidence interval, 2.1‐4.2); ORR was 0 of 23 and CBR was 4 (17.4%) of 23. In the PALOMA‐3 trial, median PFS, ORR, and CBR of palbociclib cohort were 9.5 months (95% confidence interval, 9.2‐11.0), 19%, and 67%, respectively. Conclusion: There is a limited clinical activity of palbociclib combinations after progression with everolimus combination therapy. Further studies are necessary to confirm these findings.