Naoki Kawahara

Inhibition of glycolysis and stimulation of mitochondrial biogenesis lead to increased ROS levels and cell death in HNF-1ß positive clear cell carcinoma

Abstract Ovarian clear cell carcinoma is characterized by HNF-1ß overexpression and is known to be resistant to chemotherapy. An inhibitor screening that specifically targets HNF-1ß led us to identify Actinonin as a candidate for cancer treatment. Actinonin, which is known to inhibit aminopeptidase M, has also been recognized for its antibacterial properties. We confirmed that GSK-3ß interference/inhibition, as a component of the HNF-1ß pathway, combined with Actinonin, has a highly potent antitumor effect compared to monotherapy. The same effect was observed in renal clear cell carcinoma lines expressing HNF-1ß. Actinonin promoted mitochondrial production by suppressing aerobic respiration, which decreased AMPK levels and increased ROS production. However, it also elevated GADD45α expression and induced mitophagy. GSK-3ß inhibition suppressed glycolysis and shifted energy production to OXPHOS, leading to increased ROS production. Furthermore, this combination produced excess ROS beyond metabolic capacity, which accumulated in lipid bilayers, leading to a further increase in CHOP gene expression and suppression of mitochondrial turnover. The GSK-3ß inhibitor and Actinonin combination demonstrated a powerful tumor-suppressive effect in vivo without severe side effects. Combining GSK-3ß inhibition with Actinonin can effectively eliminate cancer cells with HNF-1ß overexpression by inhibiting glycolysis and promoting mitochondrial turnover, highlighting new options for cancer therapy.

CCNE1 Is a Putative Therapeutic Target for ARID1A-Mutated Ovarian Clear Cell Carcinoma

Background: Ovarian clear cell carcinoma (OCCC) is resistant to platinum chemotherapy and is characterized by poor prognosis. Today, the use of poly (ADP-ribose) polymerase (PARP) inhibitor, which is based on synthetic lethality strategy and characterized by cancer selectivity, is widely used for new types of molecular-targeted treatment of relapsed platinum-sensitive ovarian cancer. However, it is less effective against OCCC. Methods: We conducted siRNA screening to identify synthetic lethal candidates for the ARID1A mutation; as a result, we identified Cyclin-E1 (CCNE1) as a potential target that affects cell viability. To further clarify the effects of CCNE1, human OCCC cell lines, namely TOV-21G and KOC7c (ARID1A mutant lines), and RMG-I and ES2 (ARID1A wild type lines) were transfected with siRNA targeting CCNE1 or a control vector. Results: Loss of CCNE1 reduced proliferation of the TOV-21G and KOC7c cells but not of the RMG-I and ES2 cells. Furthermore, in vivo interference of CCNE1 effectively inhibited tumor cell proliferation in a xenograft mouse model. Conclusion: This study showed for the first time that CCNE1 is a synthetic lethal target gene to ARID1A-mutated OCCC. Targeting this gene may represent a putative, novel, anticancer strategy in OCCC treatment.

The clinical trial of alternative relugolix administration for uterine leiomyoma prior to surgically treatment: a study protocol for Non-Adverse Relugolix Administration (NARA) trial

Abstract Background Uterine leiomyomas are common for reproductive-aged women and affect women’s quality of life due to heavy menstrual bleeding or dysmenorrhea. Leiomyomas grow according to estradiol exposure and decrease after post-menopause. In case serious symptoms are caused by leiomyomas, pharmacotherapy or surgical treatment is proposed. Prior to surgical treatment, pharmacotherapies aimed at the reduction of leiomyoma and uterine volume or improvement of anemia are introduced to conduct minimum invasive surgery (i.e., to reduce blood loss or surgical duration). Recently, relugolix (40 mg orally once daily) as a gonadotropin-releasing hormone (GnRH) receptor antagonist has proved its sufficient efficacy in suppressing estradiol levels without the transient estradiol flare-up compared with GnRH agonist. However, long-term administration should not be permitted liable to for climacteric disorder or osteoporosis, and evidence is lacking on the actual efficacy and extent of adverse effects of the every-other-day dosing regimen. This trial aimed to prove non-inferiority in volume reduction effect on leiomyoma and safety (i.e., reduction of adverse effects) by every-other-day administration after 2 months of everyday administration compared to daily administration throughout the duration. Methods A minimization adaptive randomized control trial (RCT) will be conducted. Patients (over 20 years old) harboring leiomyoma who will be undergoing surgical treatment will be invited to participate. Patients who are enrolled in the intervention group will receive every-other-day administration for 16 weeks after 8 weeks of daily administration. Patients who are enrolled in the control group will receive daily throughout the 24 weeks. The primary outcome is the leiomyoma volume reduction, and the secondary endpoints are the reduction of uterine volume, the occurrence of the climacteric disorder, genital bleeding days, change rate of serum hormone or bone turnover markers, and bone mineral density after 24 weeks compared to before administration. Discussion This study aims to prove both the non-inferiority in leiomyoma volume reduction and superiority in adverse effects occurrence reduction, which will provide a novel method to escape adverse effects while maintaining the effect of leiomyoma reduction. Trial registration Japan Registry of Clinical Trials jRCTs051230078. Registered on 26 July 2023.