Japan Society of Gynecologic Oncology 2022 guidelines for uterine cervical neoplasm treatment.

The Japan Society of Gynecologic Oncology (JSGO) Guidelines 2022 for the Treatment of Uterine Cervical Cancer are revised from the 2017 guideline. This guideline aimed to provide standard care for cervical cancer, indicate appropriate current treatment methods for cervical cancer, minimize variances in treatment methods among institutions, improve disease prognosis and treatment safety, reduce the economic and psychosomatic burden of patients by promoting the performance of appropriate treatment, and enhance mutual understanding between patients and healthcare professionals. The guidelines were prepared through the consensus of the JSGO Guideline Committee, based on a careful review of evidence gathered through the literature searches and the medical health insurance system and actual clinical practice situations in Japan. The guidelines comprise seven chapters and 5 algorithms. The main features of the 2022 revision are as follows: 1) added discussed points at the final consensus meeting; 2) revised the treatment methods based on the International Federation of Gynecology and Obstetrics 2018 staging system; 3) examined minimally invasive surgery based on Laparoscopic Approach to Cervical Cancer trial; 4) added clinical question (CQ) for treatments of rare histological types, gastric type, and small-cell neuroendocrine carcinoma; 5) added CQ for intensity-modulated radiation therapy; 6) added CQ for cancer genomic profiling test; and 7) added CQ for cancer survivorship. Each recommendation is accompanied by a classification of recommendation categories based on the consensus reached by the Guideline Committee members. Here, we present the English version of the JSGO Guidelines 2022 for the Treatment of Uterine Cervical Cancer.

Mechanism of Cell Death by Combined Treatment with an xCT Inhibitor and Paclitaxel: An Alternative Therapeutic Strategy for Patients with Ovarian Clear Cell Carcinoma.

Ovarian clear cell carcinoma (OCCC) is a rare subtype of epithelial ovarian carcinoma that responds poorly to chemotherapy. Glutathione (GSH) is a primary antioxidant, which protects cells against reactive oxygen species (ROS). High levels of GSH are related to chemotherapeutic resistance. The glutamine/cystine transporter xCT is essential for intracellular GSH synthesis. However, whether xCT inhibition can overcome the resistance to chemotherapeutic agents in OCCC remains unclear. This study demonstrated that combined treatment with paclitaxel (PTX) and the xCT inhibitor sulfasalazine (SAS) significantly enhanced cytotoxicity more than the individual drugs did in OCCC cells. Treatment with PTX and SAS induced apoptosis more effectively than did individual drug treatments in the cells with significant generation of ROS. Moreover, combined treatment with PTX and SAS induced ferroptosis in the cells with low expression of glutathione peroxidase (GPx4), high levels of intracellular iron and significant lipid ROS accumulation. Therefore, our findings provide valuable information that the xCT inhibitor might be a promising therapeutic target for drug-resistant OCCC. The strategy of combined administration of PTX and SAS can potentially be used to treat OCCC and help to develop novel therapeutic methods.

Impact of adjuvant chemotherapy on the overall survival of patients with resectable bulky small cell neuroendocrine cervical cancer: a JSGO-JSOG joint study.

OBJECTIVE: The aim of this study was to review the clinicopathological characteristics of small cell neuroendocrine cervical cancer (SCNEC) and to identify the optimal treatment. METHODS: The Japanese Society of Gynecologic Oncology conducted a retrospective cohort study of SCNECs enrolled in the Gynecological Tumor Registry of the Japan Society of Obstetrics and Gynecology between 2004 and 2015. All cases were modified and unified by International Federation of Gynecology and Obstetrics 2008 (Union for International Cancer Control 7th edition). RESULTS: There were 822 registered patients diagnosed with SCNEC from 2004 to 2015 which comprised 1.1% (822/73,698) of all uterine cervical cancer cases. Rates of lymph-node and distant metastasis were significantly higher in T1b2 (38.9% and 13.7%, respectively) than T1b1 (14.2% and 4.4%, respectively) (p<0.01). In IB2 and T1bN1M0 SCNEC, the 5-year survival rate with surgery followed by chemotherapy was significantly higher than that with surgery followed by radiation therapy/concurrent chemoradiation therapy (p<0.01). CONCLUSION: SNCEC tumors >4 cm in size had greater rates of lymph-node and distant metastasis when compared with tumors ≤4 cm. Adjuvant chemotherapy, rather than radiotherapy, may improve prognosis after surgery in T1bN1M0 SCNEC.

Comparison of treatment outcomes between first-line chemotherapy with or without bevacizumab for advanced ovarian, fallopian tube, and primary peritoneal cancer (Tohoku gynecologic cancer unit: TGCU-RS001 study).

BACKGROUND: Outcomes with and without bevacizumab as first-line chemotherapy in Japanese-only ovarian cancer patients have not been reported. In this study, we report a retrospective study conducted at the Tohoku Gynecologic Cancer Unit. PATIENTS AND METHODS: The study included 453 patients with stage III/IV ovarian, fallopian tube, and primary peritoneal cancer who received first-line platinum-based chemotherapy. The patients were divided into two groups: bevacizumab (168 patients) and without bevacizumab (285 patients). The primary endpoint was the rate of platinum-resistant recurrence and the secondary endpoints were the antitumor response, progression-free survival, overall survival, and adverse events. RESULTS: The objective response rates for patients with measurable diseases treated with and without bevacizumab were 84.5% and 73.0%, respectively (P = 0.0066). Platinum-resistant recurrence in the groups treated with and without bevacizumab was noted in 31 (18.4%) and 111 (38.6%) patients, respectively (P < 0.0001). The median progression-free survival for the bevacizumab and without bevacizumab groups was 23 and 15 months, respectively (P = 0.0002), and the median overall survival was not reached and 49 months, respectively (P = 0.0005). Hypertension of grade 3 or higher was observed in 21 patients (12.5%) in the bevacizumab group (P < 0.001), and proteinuria was observed in 18 patients (10.7%) and 1 patient (0.3%) in the bevacizumab and without bevacizumab groups, respectively (P < 0.001). Intestinal perforation was observed in only one patient (0.6%) in the bevacizumab group. CONCLUSION: Combination and maintenance with bevacizumab in primary chemotherapy for advanced ovarian, fallopian tube, and primary peritoneal cancer was effective in reducing platinum-resistant recurrence rates and prolonging progression-free and overall survival.

Early menopause and a low body mass index are associated with an increased risk of coronary heart disease in Japanese women.

OBJECTIVE: The primary objective was to investigate the association between early menopause and cardiovascular disease (CVD) prevalence in Japanese women. The secondary objective was to ascertain the association with CVD risk factors. METHODS: In this cross-sectional study, 7,239 naturally menopausal women from the Yamagata Cohort Study who completed an annual health visit and questionnaire between 2009 and 2015 were divided into three groups according to their age at menopause (women experiencing menopause at <45, 45-49 y, and ≥ 50 y). The diagnosis of coronary heart disease (CHD) and stroke were made by self-report, while hypertension, hyperlipidemia, and diabetes mellitus, were diagnosed by vital signs and laboratory parameters. Logistic regression analysis was used to estimate the associations between age at menopause and CVD prevalence and CVD risk factors. RESULTS: A total of 354 (4.9%) and 156 (2.2%) women reported a history of CHD and stroke, respectively. Women experiencing menopause at <45 years had a higher prevalence of CHD than those experiencing menopause at ≥50 years (OR 1.77, 95% CI 1.07-2.90; P = 0.023). Stroke, hypertension, diabetes mellitus, and hyperlipidemia were equally prevalent among the three groups. Significant interactions were observed between age at menopause and body mass index (BMI) (P = 0.025) and parity (P = 0.025). Among those with a BMI < 18.5 or parity ≥2, women experiencing menopause at <45 years had a significantly higher prevalence of CHD than those experiencing menopause at ≥50 years. CONCLUSION: Early menopause and low BMI were associated with CHD in Japanese women.

Impact of the glutathione synthesis pathway on sulfasalazine-treated endometrial cancer.

Glutathione is an antioxidant that has an important role in chemotherapeutic drug resistance in cancer. Cysteine is synthesized from cystine and is transported into the cell via the xCT antiporter. Another pathway for synthesizing cysteine involves intracellular methionine. We determined whether targeting the xCT represents a promising strategy for the treatment of endometrial cancer and identified factors that predict efficacy of this treatment strategy. In uterine serous carcinoma (USC) cell lines, the combination of cisplatin and the xCT inhibitor, sulfasalazine, significantly inhibited cell growth compared with single-agent cisplatin or sulfasalazine. Sulfasalazine treatment significantly decreased intracellular glutathione levels and induced apoptosis when combined with cisplatin in USC cell lines. On the one hand, the effectiveness of combined cisplatin and sulfasalazine was not evident in endometrioid carcinoma. USC cell lines exhibited increased expression of xCT and decreased expression of cystathionine gamma lyase (CGL), which is an enzyme involved in the synthesis of cysteine from methionine. On the other hand, endometrioid carcinoma cell lines exhibited increased CGL expression or decreased xCT expression. These findings suggest that using a glutathione synthesis pathway-based approach for selecting subjects for sulfasalazine treatment may be an effective strategy for circumventing glutathione-related chemotherapeutic drug resistance in endometrial carcinoma.

Correction: Metabolomic analysis of uterine serous carcinoma with acquired resistance to paclitaxel.

[This corrects the article DOI: 10.18632/oncotarget.25868.].

Squamous cell carcinoma arising from a mature cystic teratoma of the ovary: Successful treatment with carboplatin, paclitaxel, and bevacizumab.

Ovarian mature cystic teratomas (MCT) are usually benign. However, squamous cell carcinoma (SCC) develops in 0.17-2% of MCT. Because of its low frequency, the optimal treatment for this disease is unclear. We present a case of SCC arising from MCT. Our patient was a 30-year-old nulliparous woman complaining of right lower abdominal pain, who was referred to our hospital for a pelvic solid mass with suspected malignant ovarian tumor. A diagnosis of SCC arising from MCT was suspected based on the elevation in SCC antigen and the imaging. After surgery to remove the tumor, the diagnosis was confirmed based on the pathology. Although the surgery by radical cytoreduction was optimal, the tumor showed early recurrence. Therefore, we administrated combination chemotherapy, consisting of carboplatin, paclitaxel, and bevacizumab, followed by maintenance therapy with bevacizumab. Response to the chemotherapy regimen was complete and the patient was alive with no evidence of recurrence for 45 months after starting the initial surgery. We discuss the clinical characteristics of the malignant transformation of MCT and the treatment of SCC arising from MCT.

xCT inhibitor sulfasalazine depletes paclitaxel-resistant tumor cells through ferroptosis in uterine serous carcinoma.

Glutathione (GSH) is a primary antioxidant that protects cells against reactive oxygen species (ROS), and high levels of GSH promote cancer cell survival and resistance to chemotherapy. The glutamine transporter xCT is essential for the intracellular synthesis of GSH, whereby xCT determines the intracellular redox balance. However, whether xCT inhibition can overcome GSH-mediated resistance to chemotherapeutic agents in uterine serous carcinoma (USC) remains unclear. Thus, the present study investigated the effect of the xCT inhibitor, sulfasalazine (SAS) on cytotoxicity in paclitaxel-sensitive and -resistant USC cell lines. The molecular mechanism by which SAS induces ferroptotic cell death in paclitaxel-resistant cells was assessed. The results of the cytotoxicity assay demonstrated that SAS was more cytotoxic in paclitaxel-resistant cells compared with in -sensitive cells; however, paclitaxel cytotoxicity was not enhanced in either of the USC cell lines. Immunoblotting analysis and the cell death assays performed using ferroptosis inhibitors indicated that SAS-mediated cell death was induced through ferroptosis, and not apoptosis, in paclitaxel-resistant cells. Furthermore, ROS production was increased in paclitaxel-resistant but not in -sensitive cells, even at low SAS concentration, and JNK was activated, which is a downstream target in the Ras signaling pathway. Knockdown of JNK reversed the inhibitory effect of SAS on cell proliferation and cell death. The synthetic lethal interaction between ROS accumulation and Ras effector JNK activation may be critical for enhancing the sensitivity to ferroptotic cell death mediated by xCT inhibitor, SAS. Taken together, the results of the present study suggest that xCT inhibition may be an effective treatment for patients with recurrent paclitaxel-resistant USC.

Clinical and image features: large-vessel vasculitis after granulocyte colony stimulating factor administration.

BACKGROUND: Granulocyte colony stimulating factor (G-CSF) is known to cause vasculitis, mainly in the small vessels. Several cases of large-vessel vasculitis (LVV) caused by G-CSF have recently been reported in the literature; we retrospectively suspect that some cases of LVV in our institution were associated with administration of G-CSF. PURPOSE: To evaluate the clinical and radiological findings in our cases and to compare them with those in previous reports. MATERIAL AND METHODS: We retrospectively evaluated clinical and radiological findings in four cases of LVV that occurred after administration of G-CSF in our institution. We also reviewed papers on G-CSF-related LVV and compared their findings to ours. RESULTS: G-CSF-related LVV occurred in patients aged > 50 years and more frequently in women. Most patients developed vasculitis within 15 days after the last administration. While 14/16 patients were symptomatic, the remaining two patients were asymptomatic and diagnosed incidentally. In all cases, laboratory inflammatory markers increased, but there were no autoantibodies that clearly indicated other autoimmune vasculitis. Computed tomography revealed elevated soft tissue density around the affected vessels. CONCLUSION: LVV is among the potential adverse events of G-CSF administration. We should keep this outcome in mind when we interpret medical images of patients with previous G-CSF treatment history even if they are asymptomatic.

Successful management of cutaneous lymphangitis carcinomatosa arising from cervical cancer with paclitaxel-cisplatin and bevacizumab combination therapy: a case report and review of the literature.

BACKGROUND: Globally, cervical cancer is the fourth most common cancer in women. Here, we report a case of cutaneous lymphangitis carcinomatosa arising from cervical cancer, an extremely rare and treatment-resistant condition. CASE PRESENTATION: A 64-year-old Japanese woman presented with genital bleeding. She was diagnosed as having stage IB1 squamous cell cervical cancer and subsequently treated with radiotherapy. Approximately 2 years after the curative radiotherapy, she developed itching, skin rash, and small nodules on her left femoral and pubic area. Slight 18F-fluorodeoxyglucose uptake was detected at her left femoral skin on positron emission tomography with computed tomography. A histopathological examination was performed on a biopsy sample from an erythematous macule on her left femoral skin and vulva. Consequently, she was diagnosed as having cutaneous lymphangitis carcinomatosa arising from cervical cancer. Paclitaxel (135 mg/m2), cisplatin (50 mg/m2), and bevacizumab (15 mg/kg) combination therapy was administered every 21 days. Both itching and rash improved after three treatment cycles. After the completion of six cycles, skin erythema in the femoral and vulval area disappeared completely. Our patient experienced a 25-month symptom-free interval after the last chemotherapy session. CONCLUSION: Our findings suggest that combination chemotherapy plus bevacizumab is an effective therapeutic option in patients with cutaneous lymphangitis carcinomatosa arising from cervical cancer.

Metabolomic analysis of uterine serous carcinoma with acquired resistance to paclitaxel.

INTRODUCTION: Uterine serous carcinoma (USC) is more aggressive than other subtypes of endometrial carcinoma and is associated with a poor prognosis. We analyzed the metabolomic profile of USC with acquired resistance to paclitaxel. RESULTS: Glutathione (GSH) concentration in PTX-1 cells was higher than in USPC-1 cells. In addition, GSH concentration in the USPC-1 cells increased after treatment with paclitaxel but was unchanged in PTX-1 cells. Glucose-6-phosphate (G6P) and ribose-5-phosphate (R5P) concentrations in PTX-1 cells were higher than those in USPC-1 cells. G6P concentration in the USPC-1 cells was unchanged after treatment with paclitaxel, while it decreased in PTX-1 cells. CONCLUSION: Our results indicate that increased GSH and glucose metabolism may be related to acquiring resistance to paclitaxel in USC and thus may be targets for anti-USC therapy. MATERIALS AND METHODS: We compared metabolic profiles and reactions to paclitaxel in both a wild type USC cell line (USPC-1) and PTX-1, a cell line derived from USPC-1 which acquired paclitaxel resistance, using a capillary electrophoresis CE-MS/MS system.

Tumor lysis syndrome associated with docetaxel and carboplatin in a case with recurrent endometrial cancer.

Tumor lysis syndrome (TLS) is an oncological life-threatening complication characterized by hyperuricemia, hyperphosphatemia, and hyperkalemia, which can lead to acute renal failure, cardiac arrhythmias, cardiac arrest and seizures. Although TLS is a rare complication in patients with non-hematological malignancy, the mortality rate of TLS in solid tumors is higher than that in hematological malignancies. Acute renal injury is the most common cause of mortality associated with TLS in solid tumors. We report a case of TLS following chemotherapy for a recurrent uterine serous carcinoma. In this case, we speculated that the cause of death might be a pulmonary tumor embolism caused by TLS.

Oxidative Stress in the Visceral Fat Is Elevated in Postmenopausal Women with Gynecologic Cancer.

OBJECTIVES: This study aimed to evaluate differences in oxidative stress of visceral fat between premenopausal and postmenopausal women and clarify the antioxidant effect of estrogen on adipocytes. MATERIALS AND METHODS: Abdominal subcutaneous and omental visceral adipose tissues were obtained from 38 patients who underwent gynecological surgery. We measured the sizes of the adipocytes and evaluated the lipid peroxidation levels in the adipose tissues. We investigated whether estrogen inhibited the intracellular reactive oxygen species (ROS) production that was induced by hydrogen peroxide (H2O2) in 3T3-L1 adipocytes. RESULTS: The visceral adipocytes were 1162.4 µm2 and 1881.9 µm2 in premenopausal and postmenopausal women, respectively; hence they were significantly larger in the latter (p < 0.05). The lipid peroxidation levels were 46.7 nmoL/mg protein in premenopausal women and 99.6 nmoL/mg protein in postmenopausal women; hence the lipid peroxidation levels were significantly higher in the latter (p < 0.05). Estradiol (E2) significantly reduced the intracellular ROS levels that were induced by H2O2 in 3T3-L1 adipocytes (p < 0.01). We determined that E2 significantly increased the expression of nuclear factor erythroid 2-related factor 2 (NRF2)-dependent antioxidant genes, heme oxygenase-1 (HO-1), NAD(P)H:quinone oxidoreductase 1 (NQO1), and the glutamate-cysteine ligase (GCL) modifier subunit genes, in 3T3-L1 adipocytes (p < 0.01). CONCLUSION: Oxidative stress in the visceral fat is higher in postmenopausal women. The expression of the antioxidant genes HO-1, NQO1, and GCL was upregulated by estrogen in 3T3-L1 adipocytes. Hence, estrogen may act as an antioxidant in the adipose tissues of premenopausal women.

Activation of estrogen receptor α by estradiol and cisplatin induces platinum-resistance in ovarian cancer cells.

Activation of Estrogen receptor (ER) α (α) promotes cell growth and influences the response of cancer cell to chemotherapeutic agents. However, the mechanism by which ERα activation antagonizes cells to chemotherapy-induced cytotoxicity remains unclear. Here, we investigated the effect of cisplatin on ERα activation. In addition, we examined whether down-regulation of ERα modulate cisplatin-mediated cytotoxicity using 2 human ovarian cancer cells (Caov-3 and Ovcar-3) transduced with ERα short hairpin RNA (shRNA). The proliferation assay showed that 17ß-estradiol (E2) induced cell proliferation via activation of Akt and extracellular signal-regulated kinase (ERK) cascades, while shRNA mediated downregulation of ERα inhibited the cell proliferation. Immunoblot analysis revealed that cisplatin induced the phosphorylation of ERα at serine 118 via ERK cascade. Luciferase assay showed that cisplatin increases transcriptional activity of estrogen-responsive element (ERE). The E2-stimulated ERα activation attenuated cisplatin-induced cytotoxicity. Meanwhile, down-regulation of ERα inhibited E2-induced protective effect on cisplatin toxicity as determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays. Moreover, Pretreatment with E2 followed by cisplatin decreased the expression of cleaved PARP, and increased the expression of anti-apoptotic protein Bcl-2. Collectively, our findings suggest that activation of ERα by E2 and cisplatin can induce platinum-resistance by increasing the expression of anti-apoptotic protein in ovarian cancer cells. Therefore, our findings provide valuable information that ERα might be a promising therapeutic target for platinum-resistant ovarian cancer.

The novel JNK inhibitor AS602801 inhibits cancer stem cells in vitro and in vivo.

A phase 2 clinical trial investigating the efficacy and safety of AS602801, a newly developed JNK inhibitor, in the treatment of inflammatory endometriosis is complete. We are now examining whether AS602801 acts against human cancer cells in vitro and in vivo. In vitro, AS602801 exhibited cytotoxicity against both serum-cultured non-stem cancer cells and cancer stem cells derived from human pancreatic cancer, non-small cell lung cancer, ovarian cancer and glioblastoma at concentrations that did not decrease the viability of normal human fibroblasts. AS602801 also inhibited the self-renewal and tumor-initiating capacity of cancer stem cells surviving AS602801 treatment. Cancer stem cells in established xenograft tumors were reduced by systemic administration of AS602801 at a dose and schedule that did not adversely affect the health of the tumor-bearing mice. These findings suggest AS602801 is a promising anti-cancer stem cell agent, and further investigation of the utility of AS602801 in the treatment of cancer seems warranted.

Time-staggered inhibition of JNK effectively sensitizes chemoresistant ovarian cancer cells to cisplatin and paclitaxel.

Ovarian cancer is the most lethal gynecological malignancy, for which platinum- and taxane-based chemotherapy plays a major role. Chemoresistance of ovarian cancer poses a major obstacle to the successful management of this devastating disease; however, effective measures to overcome platinum and taxane resistance are yet to be established. In the present study, while investigating the mechanism underlying the chemoresistance of ovarian cancer, we found that JNK may have a key role in the resistance of ovarian cancer cells to cisplatin and paclitaxel. Importantly, whereas simultaneous application of a JNK inhibitor and either of the chemotherapeutic agents had contrasting effects for cisplatin (enhanced cytotoxicity) and paclitaxel (decreased cytotoxicity), JNK inhibitor treatment prior to chemotherapeutic agent application invariably enhanced the cytotoxicity of both drugs, suggesting that the basal JNK activity is commonly involved in the chemoresistance of ovarian cancer cells to cisplatin and paclitaxel in contrast to drug­induced JNK activity which may have different roles for these two drugs. Furthermore, we confirmed using non-transformed human and rodent fibroblasts that sequential application of the JNK inhibitor and the chemotherapeutic agents did not augment their toxicity. Thus, our findings highlight for the first time the possible differential roles of the basal and induced JNK activities in the chemoresistance of ovarian cancer cells and also suggest that time­staggered JNK inhibition may be a rational and promising strategy to overcome the resistance of ovarian cancer to platinum- and taxane-based chemotherapy.

GSKJ4, A Selective Jumonji H3K27 Demethylase Inhibitor, Effectively Targets Ovarian Cancer Stem Cells.

BACKGROUND/AIM: Global increase in the trimethylation of histone H3 at lysine 27 (H3K27me3) has been associated with the differentiation of normal stem cells and cancer cells, however, the role of H3K27me3 in the control of cancer stem cells (CSCs) remains poorly understood. We investigated the impact of increased H3K27me3 on CSCs using a selective H3K27 demethylase inhibitor GSKJ4. MATERIALS AND METHODS: The effect of GSKJ4 on the viability as well as on the self-renewal and tumor-initiating capacity of CSCs derived from the A2780 human ovarian cancer cell line was examined. RESULTS: GSKJ4 induced cell death in A2780 CSCs at a concentration non-toxic to normal human fibroblasts. GSKJ4 also caused loss of self-renewal and tumor-initiating capacity of A2780 CSCs surviving GSKJ4 treatment. CONCLUSION: Our findings suggest that H3K27 methylation may have an inhibitory role in the maintenance of CSCs and that GSKJ4 may represent a novel class of CSC-targeting agents.

Differential contribution of ROS to resveratrol-induced cell death and loss of self-renewal capacity of ovarian cancer stem cells.

BACKGROUND/AIM: Cancer stem cells (CSCs) are considered to contribute to the poor prognosis of ovarian cancer as a major cause of fatal recurrence. Identification of effective measures to eliminate ovarian CSCs through induction of cell death and/or loss of self-renewal capacity would, therefore, be key to successful management of ovarian cancer. MATERIALS AND METHODS: The effects of resveratrol on the viability and self-renewal capacity of CSCs derived from A2780 human ovarian cancer cells were examined. The involvement of reactive oxygen species (ROS) was also investigated. RESULTS: At a non-toxic to normal human fibroblasts concentration, resveratrol effectively killed ovarian CSCs independently of ROS, while ROS-dependently impaired the self-renewal capacity of ovarian CSCs that survived resveratrol treatment. CONCLUSION: Our findings not only shed light on a novel mechanism of action for resveratrol but also suggest that resveratrol, or its analogs, may be useful for CSC-directed therapy against ovarian cancer.

JNK suppression of chemotherapeutic agents-induced ROS confers chemoresistance on pancreatic cancer stem cells.

Chemoresistance associated with cancer stem cells (CSCs), which is now being held responsible for the pervasive therapy resistance of pancreatic cancer, poses a major challenge to the successful management of this devastating malignancy. However, the molecular mechanism underlying the marked chemoresistance of pancreatic CSCs remains largely unknown. Here we show that JNK, which is upregulated in pancreatic CSCs and contributes to their maintenance, is critically involved in the resistance of pancreatic CSCs to 5-fluorouracil (5-FU) and gemcitabine (GEM). We found that JNK inhibition effectively sensitizes otherwise chemoresistant pancreatic CSCs to 5-FU and GEM. Significantly, JNK inhibition promoted 5-FU- and GEM-induced increase in intracellular reactive oxygen species (ROS), and scavenging intracellular ROS by use of N-acetylcysteine impaired JNK inhibition-mediated promotion of the cytotoxicity of 5-FU and GEM. Our findings thus suggest that JNK may contribute to the chemoresistance of pancreatic CSCs through prevention of chemotherapeutic agents-induced increase in intracellular ROS. Our findings also suggest that JNK inhibition combined with 5-FU- and/or GEM-based regimens may be a rational therapeutic approach to effectively eliminate pancreatic CSCs.