Yoshiki Ikeda

Expression of the chrXq27.3 miRNA cluster in recurrent ovarian clear cell carcinoma and its impact on cisplatin resistance

AbstractOvarian clear cell carcinoma (OCCC) is a histological subtype of epithelial ovarian cancer and exhibits dismal prognosis due to chemoresistance. Moreover, only few effective therapeutic options exist for patients with recurrent OCCC, and an understanding of its molecular characteristics is essential for the development of novel therapeutic approaches. In the present study, we investigated unique MicroRNAs (miRNA) profiles in recurrent/metastatic OCCC and the role of miRNAs in cisplatin resistance. Comprehensive miRNA sequencing revealed that expression of several miRNAs, including miR-508-3p, miR-509-3p, miR-509-3-5p, and miR-514a-3p was remarkably less in recurrent cancer tissues when compared with that in paired primary cancer tissues. These miRNAs are located in the chrXq27.3 region on the genome. Moreover, its expression was negative in omental metastases in two patients with advanced OCCC. In vitro analyses revealed that overexpression of miR-509-3p and miR-509-3-5p reversed cisplatin resistance and yes-associated protein 1 (YAP1) was partially responsible for the resistance. Immunohistochemistry revealed that YAP1 expression was inversely correlated with the chrXq27.3 miRNA cluster expression. In conclusion, these findings suggest that alteration of the chrXq27.3 miRNA cluster could play a critical role in chemoresistance and miRNAs in the cluster and their target genes can be potential therapeutic targets.

Niraparib as a therapeutic agent for the treatment of ovarian cancer meningeal dissemination with BRCA1 mutation

AbstractThis study analyzed a 63‐year‐old woman with hereditary BRCA1 mutation. She underwent interval debulking surgery after neoadjuvant chemotherapy for high‐grade serous ovarian carcinoma (HGSOC). After 2 years of postoperative chemotherapy, she developed headache and dizziness, and a suspected metastatic cerebellar mass in left ovary was detected. Pathological analysis of the mass revealed HGSOC, which was removed surgically. Eight months and another 6 months after the surgery, local recurrence was noted; hence, she underwent CyberKnife treatment. After 3 months, cervical spinal cord metastasis was found, evidenced by left shoulder pain. Moreover, meningeal dissemination was present around the cauda equina. Chemotherapy treatment, including bevacizumab, was ineffective and increased lesions were observed. After CyberKnife treatment for the cervical spinal cord metastasis, niraparib was initiated for the meningeal dissemination. The cerebellar lesions and meningeal dissemination improved within 8 months of niraparib treatment. Although meningeal dissemination is challenging to treat, niraparib may be useful in BRCA‐mutated HGSOC.

Peritoneal restoration by repurposing vitamin D inhibits ovarian cancer dissemination via blockade of the TGF-β1/thrombospondin-1 axis

Ovarian cancer (OvCa), a lethal gynecological malignancy, disseminates to the peritoneum. Mesothelial cells (MCs) act as barriers in the abdominal cavity, preventing the adhesion of cancer cells. However, in patients with OvCa, they are transformed into cancer-associated mesothelial cells (CAMs) via mesenchymal transition and form a favorable microenvironment for tumors to promote metastasis. However, attempts for restoring CAMs to their original state have been limited. Here, we investigated whether inhibition of mesenchymal transition and restoration of MCs by vitamin D suppressed the OvCa dissemination in vitro and in vivo. The effect of vitamin D on the mutual association of MCs and OvCa cells was evaluated using in vitro coculture models and in vivo using a xenograft model. Vitamin D restored the CAMs, and thrombospondin-1 (component of the extracellular matrix that is clinically associated with poor prognosis and is highly expressed in peritoneally metastasized OvCa) was found to promote OvCa cell adhesion and proliferation. Mechanistically, TGF-β1 secreted from OvCa cells enhanced thrombospondin-1 expression in CAMs via Smad-dependent TGF-β signaling. Vitamin D inhibited mesenchymal transition in MCs and suppressed thrombospondin-1 expression via vitamin D receptor/Smad3 competition, contributing to the marked reduction in peritoneal dissemination in vivo. Importantly, vitamin D restored CAMs from a stabilized mesenchymal state to the epithelial state and normalized thrombospondin-1 expression in preclinical models that mimic cancerous peritonitis in vivo. MCs are key players in OvCa dissemination and peritoneal restoration and normalization of thrombospondin-1 expression by vitamin D may be a novel strategy for preventing OvCa dissemination.

Survival benefits of retroperitoneal lymphadenectomy for optimally-resected advanced ovarian high-grade serous carcinoma: a multi-institutional retrospective study

The survival benefits of retroperitoneal lymphadenectomy (RLNA) for epithelial ovarian cancer (EOC) remain controversial because clinical behaviors differ among subtypes. The purpose of the present study was to clarify whether RLNA increases the survival rate of advanced high-grade serous carcinoma (HGSC). This was a retrospective cohort analysis of 3,227 patients with EOC treated between 1986 and 2017 at 14 institutions. Among them, 335 patients with stage IIB-IV HGSC who underwent optimal cytoreduction (residual tumor of <1 cm) were included. Patients were divided into the RLNA group (n=170) and non-RLNA group (n=165). All pathological slides were assessed based on a central pathological review. Oncologic outcomes were compared between the two groups in the original and weighted cohorts adjusted with the inverse probability of treatment weighting. The median observation period was 49.8 (0.5-241.5) months. Overall, 219 (65%) out of 335 patients had recurrence or progression, while 146 (44%) died of the disease. In the original cohort, RLNA was a significant prognostic factor for longer progression-free survival (PFS) (hazard ratio [HR]=0.741; 95% confidence interval [CI]=0.558-0.985) and overall survival (OS) (HR=0.652; 95% CI=0.459-0.927). In the weighted cohort in which all variables were well balanced as standardized differences decreased, RLNA was also a significant prognostic factor for more favorable oncologic outcomes (PFS, adjusted HR=0.742; 95% CI=0.613-0.899) and OS, adjusted HR=0.620; 95% CI=0.488-0.787). The present study demonstrated that RLNA for stage III-IV HGSC with no residual tumor after primary debulking surgery contributed to better oncologic outcomes.

Significance of Concurrent Chemoradiotherapy as Primary Treatment in Patients with Metastatic Cervical Cancer

(1) This study investigated the prognostic impact of tumor size in patients with metastatic cervical cancer. (2) Methods: Seventy-three cervical cancer patients in our institute were stratified into two groups based on distant metastasis: para-aortic lymph node metastasis alone (IIIC2) or spread to distant visceral organs with or without para-aortic lymph node metastasis (IVB) to identify primary tumor size and concurrent chemoradiotherapy. (3) Results: The overall survival (OS) for patients with a tumor &gt;6.9 cm in size was significantly poorer than that for patients with a tumor ≤6.9 cm in the IVB group (p = 0.0028); the corresponding five-year OS rates in patients with a tumor ≤6.9 and &gt;6.9 cm were 53.3% and 13.4%, respectively. In the multivariate analysis, tumor size and primary treatment were significantly associated with survival in metastatic cervical cancer. (4) Conclusions: Tumor size ≤6.9 cm and concurrent chemoradiotherapy as the primary treatment were favorable prognostic factors for patients with metastatic cervical cancer.

An update of oncologic and obstetric outcomes of radical trachelectomy for early‐stage cervical cancer: The need for further minimally invasive treatment

AbstractAimsTo investigate the oncologic and obstetric outcomes of radical trachelectomy (RT) in patients with early‐stage cervical cancer and to evaluate the potential role of fertility‐preserving treatments in improving pregnancy outcomes while oncologic status is stable.MethodsIn this single‐institution study, we analyzed the oncologic and obstetric outcomes of 67 patients with early‐stage cervical cancer who underwent RT at Nagoya University Hospital.ResultsThe cancer recurrence rate (6.0%) and the mortality rate (1.5%) were comparable with those of previous studies. Of the 46 patients who attempted to conceive after RT, 19 (41.3%) became pregnant, and 16 gave birth. Of these 37.5% delivered at term, and delivery at less than 28 weeks of gestation occurred in 31.3% of pregnancies.ConclusionsRT is a viable treatment option for selected patients with early‐stage cervical cancer. However, the use of less invasive techniques, such as conization/simple trachelectomy and pelvic lymph node dissection, may improve pregnancy outcomes while oncologic status is stable.

Small Extracellular Vesicles from adipose-derived stem cells suppress cell proliferation by delivering the let-7 family of microRNAs in ovarian cancer

Ovarian cancer is the leading cause of death among women with gynecological cancer, and novel treatment options are urgently needed. Extracellular vesicles (EVs), including exosomes, may be one of the most promising therapeutic tools for various diseases. In this study, we aimed to investigate the therapeutic effects of adipose-derived stem cell-derived EVs (ADSC-EVs) on ovarian cancer cell lines. ADSCs and the ovarian cancer cell lines SKOV3 and OV90 were used for analysis. ADSC-EVs were isolated through ultracentrifugation and validated using a cryotransmission electron microscope, nanoparticle tracking analysis, and western blotting. Then, the effect of ADSC-EVs on ovarian cancer cells was investigated using IncuCyte and microRNA sequencing. Moreover, the potential functions of miRNAs were evaluated by gain-of function analysis and in silico analysis. ADSC-EVs suppressed SKOV3 and OV90 cell proliferation. In particular, small EVs (sEVs) from ADSCs exhibited a stronger antitumor effect than ADSC-medium/large EVs (m/lEVs). Comparison of the miRNA profiles between ADSC-sEVs and ADSC-m/lEVs, along with downstream pathway analysis, suggested the involvement of the let-7 family. Overexpression of hsa-let-7b-5p and hsa-let-7e-5p significantly suppressed the proliferation of SKOV3 cells. In silico analysis revealed that four potential target genes of hsa-let-7b-5p and hsa-let-7e-5p were significantly associated with the prognoses of the patients. ADSC-sEVs had a stronger antitumor effect than ADSC-m/lEVs. Hsa-let-7b-5p and hsa-let-7e-5p, which are highly abundant in ADSC-sEVs, suppressed cell proliferation. These findings may open up new possibilities for therapeutic approaches using ADSC-sEVs.