MUC16 overexpression induced by gene mutations promotes lung cancer cell growth and invasion

Air pollution is one of the leading causes of lung cancer. Air pollution-related lung cancer is a deteriorating public health problem, particularly in developing countries. The MUC16 gene is one of the most frequently mutated genes in air pollution-related lung cancer. In the present study, MUC16 mRNA expression was increased in ∼50% of air pollution-related lung cancer samples obtained from patients residing in air-polluted regions (Xuanwei and Fuyuan, Yunnan, China), and MUC16 mRNA levels were correlated with the degree of air pollution. Furthermore, sequencing of the captured MUC16 gene identified 561 mutation sites within the MUC16 gene in the air pollution-related lung cancer tissues. Interestingly, some mutations at specific sites and one region were associated with MUC16 mRNA up-regulation. Therefore, we further investigated the impacts of gene mutation on MUC16 expressions and cell behaviors in cultured cells by inducing certain mutations within the MUC16 gene using CRISPER/Cas9 genome editing technology. Certain mutations within the MUC16 gene induced MUC16 overexpression at both the mRNA and the protein level in the cultured cells. Additionally, MUC16 overexpression induced by gene mutations had functional effects on the behavior of lung cancer cells, including increasing their resistance to cisplatin, promoting their growth, and enhancing their migration and invasion capabilities. Based on the data, we suggest that MUC16 mutations potentially associated with air pollution may participate in the development and progression of air pollution-related lung cancer. In addition to ovarian cancer, MUC16 may be a candidate biomarker for lung cancer.

Peritoneal dissemination of ovarian cancer: role of MUC16-mesothelin interaction and implications for treatment

INTRODUCTION

Peritoneal dissemination is a particular form of malignant progression in ovarian cancer, preceding hematogenic or lymphatic dissemination. Thus, prevention of peritoneal implantation of cancer cells is envisioned to inhibit neoplastic dissemination and therefore prolong disease remission and patient's survival. Areas covered: An extended review on the role of MUC16 (CA125) and mesothelin (MSLN), expressed in a high percentage of ovarian carcinomas, indicate that this duet is relevant for the contact between cancer cells and mesothelial cells in homotypic (cancer cell-cancer cell) and heterotypic (cancer cell-mesothelial cell) interactions. This review discusses the reasons underlying the clinical failure of immunotherapeutic strategies targeting MUC16. Clinical data on MSLN targeting agents such as antibody-based immunotoxins or antibody drug conjugates are also reviewed. The promising anti-tumor effect of CAR-T cells directed to MUC16 or MSLN is emphasized. New emerging strategies specifically disrupting the MUC16-MSLN interaction are at the forefront of this review, including TRAIL ligands bound to MSLN targeting MUC16 expressing cells and single chain monoclonal antibodies and immunoadhesins recognizing MSLN-MUC16 binding domains. Expert commentary: Based on existing evidences the authors advocate that agents targeting MUC16-MSLN may add to the therapeutic armamentarium directed to abrogate peritoneal homing of ovarian cancer.

The Potential Role of MUC16 (CA125) Biomarker in Lung Cancer: A Magic Biomarker but with Adversity

Lung cancer is the second most commonly diagnosed cancer in the world. In terms of the diagnosis of lung cancer, combination carcinoembryonic antigen (CEA) and cancer antigen 125 (CA125) detection had higher sensitivity, specificity, and diagnostic odds ratios than CEA detection alone. Most individuals with elevated serum CA125 levels had lung cancer that was either in stage 3 or stage 4. Serum CA125 levels were similarly elevated in lung cancer patients who also had pleural effusions or ascites. Furthermore, there is strong evidence that human lung cancer produces CA125 in vitro, which suggests that other clinical illnesses outside of ovarian cancer could also be responsible for the rise of CA125. MUC16 (CA125) is a natural killer cell inhibitor. As a screening test for lung and ovarian cancer diagnosis and prognosis in the early stages, CA125 has been widely used as a marker in three different clinical settings. MUC16 mRNA levels in lung cancer are increased regardless of gender. As well, increased expression of mutated MUC16 enhances lung cancer cells proliferation and growth. Additionally, the CA125 serum level is thought to be a key indicator for lung cancer metastasis to the liver. Further, CA125 could be a useful biomarker in other cancer types diagnoses like ovarian, breast, and pancreatic cancers. One of the important limitations of CA125 as a first step in such a screening technique is that up to 20% of ovarian tumors lack antigen expression. Each of the 10 possible serum markers was expressed in 29-100% of ovarian tumors with minimal or no CA125 expression. Therefore, there is a controversy regarding CA125 in the diagnosis and prognosis of lung cancer and other cancer types. In this state, preclinical and clinical studies are warranted to elucidate the clinical benefit of CA125 in the diagnosis and prognosis of lung cancer.

Mesothelin-based CAR-T cells exhibit potent antitumor activity against ovarian cancer

BACKGROUND

Ovarian cancer (OC) is characterized by its rapid growth and spread which, accompanied by a low 5-year survival rate, necessitates the development of improved treatments. In ovarian cancer, the selective overexpression of Mucin-16 (MUC16, CA125) in tumor cells highlights its potential as a promising target for developing anti-tumor therapies. However, the potential effectiveness of CAR-T cell therapy that targets MUC16 in ovarian cancer cells is unknown.

METHODS

The expression of MUC16 in viable OC cells was detected using immunofluorescence and flow cytometry techniques. A MSLN-CAR construct, comprising the MUC16-binding polypeptide region of mesothelin (MSLN), a CD8 hinge spacer and transmembrane domain, 4-1BB, and CD3ζ endo-domains; was synthesized and introduced into T cells using lentiviral particles. The cytotoxicity of the resultant CAR-T cells was evaluated in vitro using luciferase assays. Cytokine release by CAR-T cells was measured using enzyme-linked immunosorbent assays. The anti-tumor efficacy of the CAR-T cells was subsequently assessed in mice through both systemic and local administration protocols.

RESULTS

MSLN-CAR T cells exhibited potent cytotoxicity towards OVCAR3 cells and their stem-like cells that express high levels of MUC16. Also, MSLN-CAR T cells were inefficient at killing SKOV3 cells that express low levels of MUC16, but were potently cytotoxic to such cells overexpressing MUC16. Moreover, MSLN-CAR T cells delivered via tail vein or peritoneal injection could shrink OVCAR3 xenograft tumors in vivo, with sustained remission observed following peritoneal delivery of MSLN-CAR T cells.

CONCLUSIONS

Collectively, these results suggested that MSLN-CAR T cells could potently eliminate MUC16- positive ovarian cancer tumor cells both in vitro and in vivo, thereby providing a promising therapeutic intervention for MUC16-positive patients.