Are platinum agents, paclitaxel and irinotecan effective for clear cell carcinoma of the ovary? DNA damage detected with γH2AX induced by anticancer agents

<p>Abstract</p> <p>Objectives</p> <p>Differences in the incidences and types of DNA damage induced by antitumor agents for clear cell carcinoma (CCC) were determined in 2 ovarian CCC cell lines using γH2AX.</p> <p>Material and methods</p> <p>The antitumor activity of anticancer agents, CDDP, CBDCA, PTX and SN-38, was examined using ovarian clear cell carcinoma cultured cell lines (OVISE and RMG-I). After culture, each cell line was treated with each anticancer agent, the cells were collected, fixed, and then reacted with the anti-γH2AX antibody. γH2AX and nuclear DNA were then simultaneously detected by flow cytometry using FITC and propidium iodide, respectively, to determine γH2AX in each cell cycle phase.</p> <p>Results</p> <p>After administration of CDDP, DNA damage was frequent in S-phase cells, while cell-cycle arrest occurred in the G1 and G2/M phases and γH2AX did not increase in CDDP-resistant cells. Sensitivities to CDDP and CBDCA differed between the two cell lines. The antitumor effect of PTX is induced by G2/M arrest, and combination treatment with CBDCA, inducing DNA damage in G2/M-phase cells, might be effective.</p> <p>Conclusions</p> <p>This is the first study in Japan to evaluate the antitumor activity of anticancer agents by focusing on the relationship between the cell cycle and DNA damage using γH2AX as an indicator. The immunocytochemical method used in this study detects γH2AX, which indicates DNA damage even at very low concentrations and with high sensitivity. Therefore, a promising method of easily and rapidly identifying agents potentially effective against CCC.</p

Cartilage repair and inhibition of the progression of cartilage degeneration after transplantation of allogeneic chondrocyte sheets in a nontraumatic early arthritis model

Introduction: Using a rat model of nontraumatic early arthritis induced by intra-articular administration of low-dose monoiodoacetic acid (MIA), we transplanted allogeneic chondrocyte sheets and examined the effects on tissue repair. Methods: MIA (0.2 mg/50 μl) was injected into the right knee of 20 male Wistar rats. Four weeks later, rats were randomly allocated into three groups: Group A was examined 4 weeks after administration of MIA; Group B, 8 weeks after MIA injection and chondrocyte sheet transplantation, and Group C, 8 weeks after MIA injection but without chondrocyte sheet transplantation. Allogeneic chondrocyte sheets were transplanted into the right knee of Group B rats. Pain was assessed as the weight distribution ratio of the damaged to undamaged limb. The OARSI score was used for histological scoring. Results: The limb weight distribution ratio indicated significantly less pain in Group B. Histological scoring showed significant differences in cartilage repair and inhibition of the progression of cartilage degeneration between Groups B and C, but not between Groups A and B, or Groups A and C. Conclusions: These findings suggest that, in this rat model of nontraumatic early arthritis induced by low-dose MIA injection, allogeneic chondrocyte sheet transplantation induces cartilage repair and suppresses cartilage degeneration. Keywords: Osteoarthritis, Chondrocyte sheet, Transplantation, Monoiodoacetic acid (MIA), OARSI scor

Expectations and Challenges of First-Line Maintenance Therapy for Advanced Ovarian Cancer

The incidence of ovarian cancer, which has had a poor prognosis, is increasing annually. Currently, the prognosis is expected to improve with the use of molecular-targeted drugs and immune checkpoint inhibitors as maintenance therapies after the first-line chemotherapy. The GOG218 and ICON7 studies reported the usefulness of bevacizumab and the SOLO-1 and PRIMA (A Phase 3, Randomized, Double-Blind, Placebo-Controlled, Multicenter Study of Niraparib Maintenance Treatment in Patients With Advanced Ovarian Cancer Following Response on Front-Line Platinum-Based Chemotherapy) studies have reported the usefulness of olaparib and niraparib, respectively. The ATHENA study investigating the usefulness of rucaparib is currently ongoing. Although clinical studies of immune checkpoint inhibitors are lagging in the field of gynecology, many clinical studies using programmed death cell-1 (PD-1) and PD-1 ligand 1 (PD-L1) antibodies are currently ongoing. Some biomarkers have been identified for molecular-targeted drugs, but none have been identified for immune checkpoint inhibitors, which is a challenge that should be addressed in the future

Comparison of Postoperative Adjuvant Chemotherapy and Concurrent Chemoradiotherapy for FIGO2018 Stage IIIC1 Cervical Cancer: A Retrospective Study

Background and Objectives: In October 2018, the International Federation of Gynecology and Obstetrics (FIGO) revised its classification of advanced stages of cervical cancer. The main points of the classification are as follows: stage IIIC is newly established; pelvic lymph node metastasis is stage IIIC1; and para-aortic lymph node metastasis is stage IIIC2. Currently, in Japan, radical hysterectomy is performed in advanced stages IA2 to IIB of FIGO2014, and concurrent chemoradiotherapy (CCRT) is recommended for patients with positive lymph nodes. However, the efficacy of CCRT is not always satisfactory. The aim of this study was to compare postoperative adjuvant chemotherapy (CT) and postoperative CCRT in stage IIIC1 patients. Materials and Methods: Of the 40 patients who had undergone a radical hysterectomy at Iwate Medical University between January 2011 and December 2016 and were pathologically diagnosed as having positive pelvic lymph nodes, 21 patients in the adjuvant CT group and 19 patients in the postoperative CCRT group were compared. Results: The 5 year survival rates were 77.9% in the CT group and 74.7% in the CCRT group, with no significant difference. There was no significant difference in overall survival or progression-free survival between the two groups. There was no significant difference between CT and CCRT in postoperative adjuvant therapy in the new classification IIIC1 stage. Conclusions: The results of the prospective Japanese Gynecologic Oncology Group (JGOG) 1082 study are pending, but the present results suggest that CT may be a treatment option in rural areas where radiotherapy facilities are limited

Novel Therapeutic Strategies for Refractory Ovarian Cancers: Clear Cell and Mucinous Carcinomas

Ovarian cancer has the worst prognosis among gynecological cancers. In particular, clear cell and mucinous carcinomas are less sensitive to chemotherapy. The establishment of new therapies is necessary to improve the treatment outcomes for these carcinomas. In previous clinical studies, chemotherapy with cytotoxic anticancer drugs has failed to demonstrate better treatment outcomes than paclitaxel + carboplatin therapy. In recent years, attention has been focused on treatment with molecular target drugs and immune checkpoint inhibitors that target newly identified biomarkers. The issues that need to be addressed include the most appropriate combination of therapies, identifying patients who may benefit from each therapy, and how results should be incorporated into the standard of care for ovarian clear cell and mucinous carcinomas. In this article, we have reviewed the most promising therapies for ovarian clear cell and mucinous carcinomas, which are regarded as intractable, with an emphasis on therapies currently being investigated in clinical studies

A New Therapeutic Strategy for Recurrent Ovarian Cancer―Bevacizumab beyond Progressive Disease

Treatment beyond progressive disease (PD) is a concept that even after drugs become ineffective, their continued use is more beneficial for patients than their discontinuation. In recent years, a concept of bevacizumab beyond PD (BBP) has attracted attention in the treatment of various cancers, and the usefulness of this concept has been evaluated. BBP has been proven to prolong overall survival (OS) in recurrent colorectal cancer and progression-free survival (PFS) in recurrent breast and lung cancers. With regard to the treatment of ovarian cancer, the MITO16/MaNGO-OV2B study (the Multicenter Phase III Randomized Study with Second Line Chemotherapy Plus or Minus Bevacizumab in Patients with Platinum Sensitive Epithelial Ovarian Cancer Recurrence After a Bevacizumab/Chemotherapy First Line) was conducted in patients with platinum-sensitive recurrence and the JGOG3023 study (the Open-Label, Randomized, Phase II Trial Evaluating the Efficacy and Safety of Standard of Care with or Without Bevacizumab in Platinum-Resistant Ovarian Cancer Patients Previously Treated with Bevacizumab for Front-Line or Platinum-Sensitive Ovarian Cancer) was conducted in patients with platinum-resistant recurrence. The MITO16/MaNGO-OV2B study, reported in the 2018 annual meeting of the American Society of Clinical Oncology, showed that BBP achieved prolonged PFS. In the JGOG3023 study, enrollment of patients was completed in December 2018, and the follow-up period has been initiated. Proving the effectiveness of BBP in the treatment of ovarian cancer may provide a new therapeutic strategy and contribute to improved treatment outcomes in patients with poor prognosis and limited therapeutic options