Programmed cell death ligand 1 ( PD ‐L1) on tumor cells suppresses anti‐tumor immunity and has an unfavorable prognostic impact in ovarian cancer patients. We herein report the pathophysiological and therapeutic impacts of PD ‐L1 disruption in ovarian cancer. PD ‐L1 was genetically disrupted in the murine ovarian cancer cell line ID 8 using clustered regularly interspaced short palindromic repeats ( CRISPR )/Cas9‐mediated genome editing. PD ‐L1 knockout ( KO ) and control ovarian cancer cells were intraperitoneally inoculated into syngeneic mice, and survival and tumor dissemination were evaluated. Survival times were significantly longer in the PD ‐L1‐ KO ID 8‐inoculated groups than in their control groups, and its therapeutic benefit was enhanced in combination with the cisplatin treatment. Tumor weights and ascites volumes were significantly lower in the PD ‐L1‐ KO ID 8 groups than in their control groups. Immunohistochemical and immunofluorescence analyses showed that intratumoral CD 4 + T cells, CD 8 + T cells, NK cells and CD 11c + M1 macrophages were significantly increased, whereas regulatory T cells were significantly decreased in the PD ‐L1‐ KO ID 8 groups compared with those in their control groups. The intratumoral mRNA expression of interferon‐γ, tumor‐necrosis factor‐α, interleukin ( IL )‐2, IL ‐12a, CXCL 9 and CXCL 10 was significantly stronger, while that of IL ‐10, vascular endothelial growth factor, CXCL 1 and CXCL 2 was significantly weaker in the PD ‐L1‐ KO ID 8 groups. These results indicate that CRISPR /Cas9‐mediated PD ‐L1 disruption on tumor cells promotes anti‐tumor immunity by increasing tumor‐infiltrating lymphocytes and modulating cytokine/chemokine profiles within the tumor microenvironment, thereby suppressing ovarian cancer progression. These results suggest that PD ‐L1‐targeted therapy by genome editing may be a novel therapeutic strategy for ovarian cancer.

Malignant melanoma (MM) in the female genital tract accounts for less than 2% of all melanomas, and the vast majority associated occur in the vulva and vagina. Primary MM of the uterine cervix is extremely rare and its prognosis is very poor. We report a case of primary MM of the cervix with dissemination throughout the vaginal wall. A 66-year-old woman presented with postmenopausal bleeding. Gynecologic examination demonstrated a 2 cm polypoid blackish-pigmented tumor on the cervix with multiple small blackish-pigmented lesions throughout the vaginal wall. Cervical Pap smear cytology showed malignant melanoma. MRI and PET/CT did not detect any distant or lymph node metastases. She underwent radical hysterectomy, pelvic lymphadenectomy, and total vaginectomy. The pathological diagnosis was FIGO stage IIIA primary cervical MM. She received adjuvant chemotherapy with 6 courses of dacarbazine, but 6 months later, multiple lung metastases were detected. Despite 4 courses of anti-PD-1 antibody (nivolumab) treatment, she died of the disease 13 months after surgery.

Liquid biopsies of circulating tumor DNA (ctDNA) have recently been used as a non-invasive diagnostic tool for detecting tumor-specific mutations. We present a study of ctDNA liquid biopsies in gynecological cancer using an ultrasensitive next-generation sequencing-based method for ctDNA detection named CAncer Personalized Profiling by deep Sequencing (CAPP-Seq). We performed CAPP-Seq with plasma-ctDNA obtained from 16 patients with gynecological cancer. In all cases, at least one non-synonymous somatic mutation was detected in the ctDNA. In the pre-treatment ctDNA, 4 of 16, 4/16, 5/16, 2/16, 2/16, and 2/16 patients had TP53 , KRAS , APC , PIK3CA , BRCA1 , and EGFR mutations, respectively. MET gene copy-number gains were detected in the ctDNA of 2 of 16 patients, and FISH analysis of the paired tumor samples confirmed these results. In 2 neoadjuvant chemotherapy-treated ovarian cancer patients, the changes in gene mutation patterns were associated with the treatment response. These findings suggest that CAPP-Seq-based liquid biopsies can be used for the genetic characterization of independent gynecological cancers with high frequency, and might be clinically useful for non-invasive tumor genotyping and therapeutic response monitoring.

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Liquid biopsies from circulating tumor DNA (ctDNA) have been employed recently as a non-invasive diagnostic tool for detecting cancer-specific gene mutations. Here, we show the comprehensive gene mutation profiles of ctDNA in 51 patients with different histological subtypes of stage I–IV ovarian cancer, and their association with clinical outcomes. The ctDNA extracted from pre-treatment patients’ plasma were analyzed using Cancer Personalized Profiling by Deep Sequencing targeting 197 genes. Of 51 patients, 48 (94%) showed one or more non-synonymous somatic mutations, including TP53 (37.3%), APC (17.6%), KRAS (15.7%), EGFR (13.7%), MET (11.8%), PIK3CA (11.8%), NPAP1 (11.8%), and ALK (9.8%). The most frequently mutated genes were as follows: TP53 in high-grade serous carcinoma (66.7%), APC in clear cell carcinoma (30.8%), PIK3CA in endometrioid carcinoma (40%), and KRAS in mucinous carcinoma (66.7%). Higher cell-free (cf)DNA concentration significantly correlated with worse progression-free survival (PFS) in all patients as well as stage III–IV patients (p = 0.01 and 0.005, respectively). Further, patients with any pathogenic mutations showed significantly worse PFS (p = 0.048). Blood tumor mutational burden detected from ctDNA did not significantly correlate with the histological subtypes or survival. Collectively, clinico-genomic profiles of individual ovarian cancer patients could be identified using ctDNA and may serve as a useful prognostic indicator. These findings suggest that ctDNA-based gene profiling might help in establishing personalized therapeutic strategies.