Allelic loss of HLA class I facilitates evasion from immune surveillance in cervical intraepithelial neoplasia.

Loss of heterozygosity (LOH) has been reported to occur in HLA regions in cervical intraepithelial neoplasia (CIN) and cervical cancer. However, the details of how this is related to the progression of CIN have been unclear. In this study, we examined the human papillomavirus (HPV) antigen-presenting capacity of people with CIN and the significance of LOH of HLA class I in the progression of CIN. It was shown that differences in antigen-presenting capacity among each case depended on HLA types, not HPV genotypes. Focusing on the HLA type, there was a positive correlation between antigen-presenting capacity against HPV and the frequency of allelic loss. Furthermore, the lost HLA-B alleles had a higher HPV antigen-presenting capacity than intact alleles. In addition, frequency of LOH of HLA class I was significantly higher in advanced CIN (CIN2-3) than in cervicitis or early-stage CIN (CIN1): around half of CIN2-3 had LOH of any HLA class I. Moreover, the antigen-presenting capacity against E5, which is the HPV proteins that facilitate viral escape from this immune surveillance by suppressing HLA class I expression, had the most significant impact on the LOH in HLA-B. This study suggests that HPV evades immune surveillance mechanisms when host cells lose the capacity for antigen presentation by HLA class I molecules, resulting in long-term infection and progression to advanced lesions.

Late Recurrence of Ovarian Cancer after 18 Years of Disease-Free Survival: A Case Report and Review of the Literature.

We present a case of recurrent ovarian cancer at the age of 75, gravida 1 para 0, with 18 years of disease-free survival. Chemotherapy brought a 10-month partial response status; to further improve the overall survival, the patient was evaluated using the AGO score (DESKTOP III trial, 2020), which was originally intended for cases immediately after the diagnosis of recurrence; the score has indicated a significant outcome; the patient went through a hepatosplenic metastatic site resection; and complete resection was achieved. Subsequently, the PARP inhibitor was introduced, which has led to 14 months of disease-free survival. Fifteen cases of late recurrence of epithelial ovarian cancer have been reported and are summarized at the end of this paper.

Cancer of unknown primary histologically, genetically and spatially diagnosed as left ovary­derived cancer: A case report.

Cancer of unknown primary (CUP) is a heterogeneous syndrome of metastatic cancer in which the primary site cannot be determined even after a standard and comprehensive search. The present report describes a case in which the spatial distribution of the lymph node metastases contributed to the identification of the primary site. While the standard workup did not identify the primary tumor, genomic profiling analysis was useful in therapeutic management. A 68-year-old woman presented with a cancerous pleural effusion (adenocarcinoma). The primary site could not be identified, and the pleural effusion resolved spontaneously. After 11 months, the patient had elevated Krebs von den Lungen-6 and cancer antigen 125 levels, and multiple enlarged lymph nodes. Pathological diagnosis based on a biopsy sample of the para-aortic lymph nodes indicated that the tumor was a high-grade serous carcinoma of possible gynecological organ origin. The patient underwent surgery, including hysterectomy, bisalpingo-oophorectomy and lymph node dissection. Although there were no primary sites in the gynecological organs, marked lymphovascular invasion was found around the left ovary, suggesting a left ovary-derived tumor. Genetic testing revealed a high loss of heterozygosity score and high tumor mutational burden (TMB). The patient received paclitaxel and carboplatin therapy followed by a poly ADP-ribose polymerase inhibitor as regimens for ovarian cancer and achieved complete remission. The unique course of the disappearance of the effusion and the absence of tumor in the adnexa might be associated with the high immunogenicity of the tumor characterized by the high TMB. This case may provide insights into the pathogenesis of CUP.

Risk stratification of invasive cervical cancer diagnosed after cervical conization.

BACKGROUND: Cervical intraepithelial neoplasia (CIN) diagnosis is based on colposcopy-aided histological examination. However, its accuracy in CIN diagnosis is limited. Some invasive cervical cancers (ICCs) are diagnosed after cervical conization. Therefore, risk stratification of undetected ICC is particularly important for the management of patients with CIN. This study aimed to identify the risk factors for undetected ICC. We especially focused on the association of human papillomavirus (HPV) genotypes. METHODS: We retrospectively reviewed the clinicopathological characteristics (including age, parity, and preoperative diagnosis) and HPV genotypes of 348 patients diagnosed with CIN or adenocarcinoma in situ (AIS) who underwent cervical conization at our hospital between 2008 and 2016. The relationship between preoperative factors, including HPV genotypes and post-conization ICC, was evaluated. RESULTS: Among the 348 patients, 322, 7, and 19 had preoperative CIN3, CIN2, and AIS, respectively; 181 were nulliparous. The median patient age was 41 (23-83) years. HPV genotyping was performed on 237 patients. Overall, post-conization ICC was detected in 16 patients (4.6%). Multivariate analysis showed that nulliparity and HPV16 positivity were the independent risk factors for post-conization ICC (OR: 6.01, P = 0.0302; OR: 5.26, P = 0.0347, respectively). The combination of HPV16 status and parity improved diagnostic accuracy. Seven of 53 HPV16-positive cases (13%) without childbirth history were diagnosed with post-conization ICC. In contrast, none of the HPV16-negative cases with childbirth history was diagnosed with post-conization ICC. CONCLUSION: HPV16 positivity and nulliparity were identified as risk factors for undetected ICC. Careful treatment selection and preoperative scrupulous examination are especially important in these cases.

Heterogeneous effects of cytotoxic chemotherapies for platinum-resistant ovarian cancer.

BACKGROUND: Single-agent chemotherapy with or without bevacizumab (Bev) is a standard therapy for platinum-resistant ovarian cancer (PR-OC). However, there is a lack of literature on chemotherapy agent selection in heterogenous PR-OC. Therefore, we aimed to clarify the heterogeneous treatment effects of each chemotherapy agent. METHODS: Patients who underwent single-drug chemotherapy agents or Bev combination therapy for PR-OC between January 2009 and June 2022 were included in this study. We assessed the impact of each chemotherapy agent on the time to treatment failure (TTF) according to histological type, platinum-free interval (PFI), and Bev usage. RESULTS: A total of 158 patients received 343 different chemotherapy regimens. In patients with clear cell carcinoma/mucinous carcinoma (CC/MC), gemcitabine (GEM) had the strongest effect with a median TTF of 5.3 months, whilst nedaplatin (NDP) had the lowest effect with a median TTF of 1.4 months. In contrast, in the non-CC/MC group, irinotecan (CPT-11) and NDP had a better TTF than GEM and pegylated liposomal doxorubicin (PLD). There were notable differences in the treatment efficacy of NDP according to PFI. Specifically, NDP prolonged the TTF in patients with a PFI ≥ 3 months. Compared with GEM alone, GEM + Bev tended to prolong the TTF more effectively; however, an additive effect was not observed with PLD + Bev. CONCLUSIONS: This study demonstrated that the effect of chemotherapy agents differed according to the tumor and background characteristics of the patient. Our findings will improve selection of effective therapies for patients with PR-OC by considering their background characteristics.

Prognosis of patients with endometrial cancer or atypical endometrial hyperplasia after complete remission with fertility-sparing therapy.

PURPOSE: Although many patients with endometrial cancer (EC) or atypical endometrial hyperplasia (AEH) achieve complete remission (CR) after high-dose medroxyprogesterone acetate (MPA) treatment, no consensus has been reached on management after CR. Currently, patients receive estrogen-progestin maintenance therapy, but no recommendations exist regarding the duration of maintenance therapy or whether hysterectomy should be considered. This study aimed to provide insights into the management of EC/AEH after achieving CR. METHODS: We retrospectively investigated the prognosis of 50 patients with EC or AEH who achieved CR after MPA therapy. We assessed the association between disease recurrence and clinicopathological features and the pre- and post-operative histological diagnoses of patients who underwent hysterectomy. RESULTS: The median follow-up duration was 34 months (range: 1-179 months). Recurrence was observed in 17 patients. Among the clinical characteristics investigated, only the primary disease was significantly associated with disease recurrence; patients with EC had a higher risk of recurrence than those with AEH (p = 0.037). During the observation period, 27 patients attempted pregnancy, and 14 pregnancies resulted in delivery. Patients who gave birth had significantly longer relapse-free survivals than those who did not (p = 0.031). Further, 16 patients underwent hysterectomies, and AEH was detected postoperatively in 4 of 11 patients (36.4%) with no preoperative abnormalities. CONCLUSIONS: We identified several clinical features of patients with EC and AEH after CR. Given the high probability of endometrial abnormalities detected postoperatively, hysterectomy may be considered for patients who no longer want children.

Metastasis of Ovarian Cancer to the Descending Colon.

Colonic metastasis from ovarian cancer is extremely rare, with only seven reported cases. A 77-year-old woman who had previously undergone surgery for ovarian cancer was admitted to a local hospital with anal bleeding. Histopathological analysis confirmed the presence of adenocarcinoma. Colonoscopy revealed a descending colon tumor. The patient was diagnosed with Union for International Cancer Control T3N0M0 descending colon cancer or colon metastasis of the ovarian cancer. Laparoscopic left colectomy was performed; intraoperative frozen section diagnosis confirmed metastasis from ovarian cancer, and the absence of invasion to the serosal surface suggested hematogenous metastasis. This is the first case of colonic metastasis from ovarian cancer that was diagnosed using an intraoperative frozen section and laparoscopically treated.

Effect of pelvic radiotherapy on patients with stage IB­IIA cervical cancer after radical hysterectomy: A single­center retrospective study.

The effects of post-operative adjuvant radiotherapy (RT) on intermediate-risk patients with cervical cancer have not been fully elucidated. Therefore, the present study aimed to investigate the impact of RT on intermediate-risk cervical cancer. The data of 112 patients with stage IB and IIA cervical cancer treated with radical hysterectomy between January 2009 and December 2018 were retrospectively reviewed. Overall survival (OS), progression-free survival (PFS), and the frequency of adverse events were compared between patients with and without adjuvant RT (RT+ and RT-, respectively). Subgroup analyses of PFS based on tumor size, cervical stromal invasion, lymphovascular space invasion and histology [squamous cell carcinoma (SCC) vs. non-SCC] were performed. Among the 112 patients, 41 received adjuvant RT. Although there were no significant differences in OS or PFS between the RT+ and RT- groups, the frequency of adverse events was much higher in the RT+ group. Patients in the RT+ group also had more recurrent risk factors than those in the RT- group. Based on the subgroup analyses, although no significant differences were observed between any of the groups, RT demonstrated a different impact on PFS between SCC and non-SCC: No difference was observed in the SCC group, whereas patients in the RT+ group tended to have poorer prognoses compared to those in the RT- group of the non-SCC group. These results suggest that the impact of post-operative RT on stage IB and IIA cervical cancer is limited and is accompanied by increased adverse events. The eligibility of patients for post-operative RT should be carefully determined based on the therapeutic effect of RT in each subgroup.

Suspicious Positive Peritoneal Cytology (Class III) in Endometrial Cancer Does Not Affect Prognosis.

Positive peritoneal cytology is a poor prognostic factor in patients with advanced endometrial cancer. Suspicious positive peritoneal cytology (class III) is commonly encountered in clinical practice. However, no standard treatment protocol exists for its management. Here, we investigated a possible relationship between suspicious positive peritoneal cytology, disease stage, risk factors, and endometrial cancer prognosis. We included patients diagnosed with endometrial cancer who underwent total hysterectomy and peritoneal cytology at the University of Tokyo Hospital between 2008 and 2022. Overall, 670 patients were included in the analyses; both demographic and clinical data of the patients were collected. The proportion of patients with lymph node metastasis was significantly different between peritoneal cytology groups, showing lymph node metastasis to be more extensive in patients with positive or suspicious positive peritoneal cytology than in patients with negative peritoneal cytology (p < 0.05). Thirty-nine patients had suspicious positive peritoneal cytology. Omental resection and biopsy were performed in 16 cases. No case of omental metastasis was found. Among patients with suspected ascites cytology, no patient experienced symptom recurrence or death. Therefore, monitoring lymph node metastasis in suspicious positive cases is essential. Moreover, a change of treatment method based on the finding of suspected positive peritoneal cytology is not necessary.

Transiently elevated D-dimer levels post-concentrated ascites reinfusion therapy cannot be used to predict deep vein thrombosis-pulmonary embolism.

AIM: Cell-free and concentrated ascites reinfusion therapy (CART) is useful for treating malignant ascites. We have previously experienced cases with no DVT-PE despite a marked elevation in D-dimer post-CART. In this study, we assessed the changes in the D-dimer levels in patients who received CART and investigated the association between elevated D-dimer levels and occurrence of DVT-PE. METHODS: We performed an observational retrospective analysis of patients with gynecological malignancies treated with CART between March 2018 and April 2021. The selected patients had their D-dimer levels measured before and post-CART. The presence or absence of clinical DVT-PE findings was then examined, and contrast-enhanced computed tomography was performed using a DVT protocol in some cases. RESULTS: Eleven patients received 17 CART procedures in this study. Patients of 16 procedures (94.1%) showed a significant elevation in D-dimer levels on day 1 post-CART. Changes in D-dimer levels were monitored in these patients of 16 procedures. In all 16 cases, the D-dimer levels decreased after day 2 post-CART. Only one patient, who presented with respiratory failure, out of the patients of 16 procedures (6.2%) with elevated D-dimer levels on day 1 had PE. CONCLUSIONS: D-dimer elevation after CART is likely to be transient and a false-positive. None of the patients in this study had PE if they were asymptomatic after CART, there is no need to strongly suspect PE only by D-dimer elevation. In conclusion, D-dimer measurement immediately post-CART is not helpful in predicting the diagnosis of DVT-PE.

Occurrence of seromucinous borderline tumours in the peritoneal lesions after bilateral salpingo-oophorectomy.

A 65-year-old woman with a previous history of bilateral salpingo-oophorectomy had peritoneal cysts, increasing in size over 15 years and an increasing cancer antigen 19-9 (CA 19-9) level. The size of the cysts eventually reached 86 mm and 70 mm. As malignant transformation of endometriosis was suspected, we performed peritoneal cystectomy and hysterectomy. Histopathology revealed seromucinous borderline tumours (SMBTs) derived from endometriosis. One month after surgery, her CA 19-9 level had decreased. It is rare for SMBT to occur after bilateral salpingo-oophorectomy; surgical management is the best treatment at present.

Usefulness of biopsy by office hysteroscopy for endometrial cancer: A case report.

A diagnostic biopsy for endometrial cancer is performed via dilation and curettage (D&C). However, D&C may miss endometrial cancer lesions due to of its 'blind' approach. Hysteroscopy is a useful method that can be used to detect endometrial cancer lesions. In addition, office hysteroscopy is easy to be scheduled and does not require anesthesia. The patient was a 40-year-old woman with suspected endometrial cancer; however, it could not be diagnosed by D&C and biopsy using hysteroscopy during hospitalization. Office hysteroscopy during the proliferative phase indicated that the suspicious endometrial cancerous lesion was minimal at the isthmus of the uterus with atypical vessels and a white spot, for which biopsy was performed. Pathological diagnosis was endometrioid carcinoma with squamous differentiation, G1. Therefore, total laparoscopic hysterectomy, bilateral salpingo-oophorectomy and pelvic lymphadenectomy were performed. In this case, it was difficult to detect minimal lesion in the secretory phase because the endometrial thickness hid the endometrial cancer. It is easy to perform office hysteroscopy in the proliferative phase. This case indicated that office hysteroscopy is a useful method to diagnose and perform biopsy for minimal lesions.

Differential expression of human papillomavirus 16-, 18-, 52-, and 58-derived transcripts in cervical intraepithelial neoplasia.

BACKGROUND: Human papillomavirus (HPV) infection is a primary cause of cervical cancer. Although epidemiologic study revealed that carcinogenic risk differs according to HPV genotypes, the expression patterns of HPV-derived transcripts and their dependence on HPV genotypes have not yet been fully elucidated. METHODS: In this study, 382 patients with abnormal cervical cytology were enrolled to assess the associations between HPV-derived transcripts and cervical intraepithelial neoplasia (CIN) grades and/or HPV genotypes. Specifically, four HPV-derived transcripts, namely, oncogenes E6 and E6*, E1^E4, and viral capsid protein L1 in four major HPV genotypes-HPV 16, 18, 52, and 58-were investigated. RESULTS: The detection rate of E6/E6* increased with CIN progression, whereas there was no significant change in the detection rate of E1^E4 or L1 among CIN grades. In addition, we found that L1 gene expression was HPV type-dependent. Almost all HPV 52-positive specimens, approximately 50% of HPV 58-positive specimens, around 33% of HPV 16-positive specimens, and only one HPV18-positive specimen expressed L1. CONCLUSIONS: We demonstrated that HPV-derived transcripts are HPV genotype-dependent. Especially, expression patterns of L1 gene expression might reflect HPV genotype-dependent patterns of carcinogenesis.

Multistate Markov Model to Predict the Prognosis of High-Risk Human Papillomavirus-Related Cervical Lesions.

Cervical intraepithelial neoplasia (CIN) has a natural history of bidirectional transition between different states. Therefore, conventional statistical models assuming a unidirectional disease progression may oversimplify CIN fate. We applied a continuous-time multistate Markov model to predict this CIN fate by addressing the probability of transitions between multiple states according to the genotypes of high-risk human papillomavirus (HPV). This retrospective cohort comprised 6022 observations in 737 patients (195 normal, 259 CIN1, and 283 CIN2 patients at the time of entry in the cohort). Patients were followed up or treated at the University of Tokyo Hospital between 2008 and 2015. Our model captured the prevalence trend satisfactory, particularly for up to two years. The estimated probabilities for 2-year transition to CIN3 or more were the highest in HPV 16-positive patients (13%, 30%, and 42% from normal, CIN1, and CIN2, respectively) compared with those in the other genotype-positive patients (3.1%-9.6%, 7.6%-16%, and 21%-32% from normal, CIN1, and CIN2, respectively). Approximately 40% of HPV 52- or 58-related CINs remained at CIN1 and CIN2. The Markov model highlights the differences in transition and progression patterns between high-risk HPV-related CINs. HPV genotype-based management may be desirable for patients with cervical lesions.

Blood Vessel Invasion Is a Strong Predictor of Postoperative Recurrence in Endometrial Cancer.

OBJECTIVES: Although lymphovascular space invasion is a prognostic factor for the recurrence of resectable endometrial cancer, the differential impacts of lymphatic vessel invasion (LVI) and blood vessel invasion (BVI) on the recurrence of endometrial cancer are poorly described. We investigated the prognostic significance of LVI and BVI on the recurrence of endometrial cancer and their association with patterns of recurrence. METHODS: We retrospectively reviewed 376 patients with stage I to III endometrial cancer who underwent surgery with curative intent at our institution between 2007 and 2015. The associations of the presence of lymphovascular space invasion or LVI and BVI with recurrence-free survival and patterns of recurrence were evaluated. RESULTS: Lymphovascular space invasion positivity was an independent prognostic factor for recurrence-free survival (hazards ratio [HR], 3.070; 95% confidence interval [CI], 1.404-6.824; P = 0.0048). However, when categorized by LVI versus BVI, the latter was a strong independent prognostic factor (HR, 2.697; CI, 1.288-5.798; P = 0.0081), whereas the former was not (HR, 1.740; CI, 0.795-3.721; P = 0.1637). Hematogenous metastasis was the most prevalent form of recurrence in endometrial cancer (24 [50%] of all 48 recurrent cases). Notably, 17 (19.5%) of 87 patients with BVI developed hematogenous metastases, compared with 7 (2.4%) of 289 without BVI (χ test, P < 0.0001). CONCLUSIONS: Blood vessel invasion rather than LVI was a strong predictor of postoperative recurrence in stage I to III endometrial cancer, probably due to its predisposition to hematogenous metastases.

Therapeutic significance of targeting survivin in cervical cancer and possibility of combination therapy with TRAIL.

Loss of p53 function due to human papillomavirus (HPV) infection induces resistance to apoptosis in cervical cancer cells. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), which induces apoptosis in a p53-independent manner, may provide an alternative strategy for treating cervical cancer. Survivin, an antiapoptotic protein that is highly expressed in cancer cells, regulates apoptosis and the cell cycle. Here, we investigated the therapeutic potential of targeting survivin, while focusing on the TRAIL-induced apoptosis pathway. The viability and cell cycle of HPV16-positive CaSki and SiHa cells were assessed after survivin knockdown by small interfering RNA (si-survivin). E-cadherin expression was also assessed after si-survivin treatment, using western blotting. SiHa (a TRAIL-resistant cell line) was used for further studies. The small molecule YM155 and resveratrol (RVT; a polyphenol with the potential to suppress survivin expression) were used as survivin inhibitors. The effects of si-survivin and survivin inhibitors on TRAIL- or cisplatin (CDDP)-induced apoptosis were analyzed by annexin-V staining. si-survivin treatment decreased cell viability and led to G2/M arrest, accompanied by morphological changes and E-cadherin upregulation in both CaSki and SiHa cells. si-survivin and YM155 synergistically sensitized TRAIL-resistant SiHa cells to TRAIL-induced apoptosis (p < 0.05). However, si-survivin and YM155 only slightly increased CDDP-induced apoptosis. RVT markedly enhanced TRAIL-induced apoptosis by suppressing survivin expression. Targeting of survivin expression might be an ideal strategy for cervical cancer treatment as it would decrease viable cell number and enhance apoptosis sensitivity. Further, combination therapy with TRAIL, rather than CDDP, may be compatible with the proposed survivin-targeting strategy.

Detachment from the primary site and suspension in ascites as the initial step in metabolic reprogramming and metastasis to the omentum in ovarian cancer.

Cancer cell metabolism is currently considered to be context dependent, and metabolic reprogramming is being widely investigated. It is known that ovarian cancer often metastasizes to the omentum. Given that the omentum itself contains a high concentration of adipocytes, ovarian cancer is thought to be a good model for research into metabolic reprogramming (particularly the shift to lipid metabolism). The present study investigated the switch to lipid metabolism in the metabolic reprogramming of ovarian cancer cells. The present study first considered the possibility of epigenetic involvement. Using an open database (GSE 85293 and GSE2109), the methylation status and gene expression patterns of the primary tumor site (ovary) and the metastatic tumor site (omentum) were compared. However, no evidence was obtained regarding the involvement of epigenetics (at least in terms of DNA methylation). The influence of suspension in ascites on metabolism was then considered, and a suspension culture was used as an in vitro model. It was demonstrated that ovarian cancer cells that are detached from the primary site and suspended in ascites have enhanced lipid metabolism. Additionally, it was demonstrated that these cells express high levels of the cancer stem cell (CSC) marker cluster of differentiation 44 and c-kit in a balanced manner as they approach the omentum. Accordingly, these cells activate the mammalian target of rapamycin pathway, which is thought to be advantageous for cancer cell metastasis. In conclusion, the present study proposed one explanation for why ovarian cancer cells are likely to disseminate to the peritoneal cavity, and in particular to the omentum.

Intracellular signaling entropy can be a biomarker for predicting the development of cervical intraepithelial neoplasia.

While the mortality rates for cervical cancer have been drastically reduced after the introduction of the Pap smear test, it still is one of the leading causes of death in women worldwide. Additionally, studies that appropriately evaluate the risk of developing cervical lesions are needed. Therefore, we investigated whether intracellular signaling entropy, which is measured with microarray data, could be useful for predicting the risks of developing cervical lesions. We used three datasets, GSE63514 (histology), GSE27678 (cytology) and GSE75132 (cytology, a prospective study). From the data in GSE63514, the entropy rate was significantly increased with disease progression (normal < cervical intraepithelial neoplasia, CIN < cancer) (Kruskal-Wallis test, p < 0.0001). From the data in GSE27678, similar results (normal < low-grade squamous intraepithelial lesions, LSILs < high-grade squamous intraepithelial lesions, HSILs ≤ cancer) were obtained (Kruskal-Wallis test, p < 0.001). From the data in GSE75132, the entropy rate tended to be higher in the HPV-persistent groups than the HPV-negative group. The group that was destined to progress to CIN 3 or higher had a tendency to have a higher entropy rate than the HPV16-positive without progression group. In conclusion, signaling entropy was suggested to be different for different lesion statuses and could be a useful biomarker for predicting the development of cervical intraepithelial neoplasia.

Regeneration of cervical reserve cell-like cells from human induced pluripotent stem cells (iPSCs): A new approach to finding targets for cervical cancer stem cell treatment.

Cervical reserve cells are epithelial progenitor cells that are pathologically evident as the origin of cervical cancer. Thus, investigating the characteristics of cervical reserve cells could yield insight into the features of cervical cancer stem cells (CSCs). In this study, we established a method for the regeneration of cervical reserve cell-like properties from human induced pluripotent stem cells (iPSCs) and named these cells induced reserve cell-like cells (iRCs). Approximately 70% of iRCs were positive for the reserve cell markers p63, CK5 and CK8. iRCs also expressed the SC junction markers CK7, AGR2, CD63, MMP7 and GDA. While iRCs expressed neither ERα nor ERß, they expressed CA125. These data indicated that iRCs possessed characteristics of cervical epithelial progenitor cells. iRCs secreted higher levels of several inflammatory cytokines such as macrophage migration inhibitory factor (MIF), soluble intercellular adhesion molecule 1 (sICAM-1) and C-X-C motif ligand 10 (CXCL-10) compared with normal cervical epithelial cells. iRCs also expressed human leukocyte antigen-G (HLA-G), which is an important cell-surface antigen for immune tolerance and carcinogenesis. Together with the fact that cervical CSCs can originate from reserve cells, our data suggested that iRCs were potent immune modulators that might favor cervical cancer cell survival. In conclusion, by generating reserve cell-like properties from iPSCs, we provide a new approach that may yield new insight into cervical cancer stem cells and help find new oncogenic targets.

Targeting glutamine metabolism and the focal adhesion kinase additively inhibits the mammalian target of the rapamycin pathway in spheroid cancer stem-like properties of ovarian clear cell carcinoma in vitro.

Ovarian cancer is one of the leading causes of death in the world, which is linked to its resistance to chemotherapy. Strategies to overcome chemoresistance have been keenly investigated. Culturing cancer cells in suspension, which results in formation of spheroids, is a more accurate reflection of clinical cancer behavior in vitro than conventional adherent cultures. By performing RNA-seq analysis, we found that the focal adhesion pathway was essential in spheroids. The phosphorylation of focal adhesion kinase (FAK) was increased in spheroids compared to adherent cells, and inhibition of FAK in spheroids resulted in inhibition of the downstream mammalian target of the rapamycin (mTOR) pathway in ovarian clear cell carcinomas. This result also suggested that only using a FAK inhibitor might have limitations because the phosphorylation level of FAK could not be reduced to the level in adherent cells, and it appeared that some combination therapies might be necessary. We previously reported that glutamine and glutamate concentrations were higher in spheroids than adherent cells, and we investigated a synergistic effect targeting glutamine metabolism with FAK inhibition on the mTOR pathway. The combination of AOA, a pan-transaminase inhibitor, and PF 573228, a FAK inhibitor, additively inhibited the mTOR pathway in spheroids from ovarian clear cell carcinomas. Our in vitro study proposed a rationale for the positive and negative effects of using FAK inhibitors in ovarian clear cell carcinomas and suggested that targeting glutamine metabolism could overcome the limitation of FAK inhibitors by additively inhibiting the mTOR pathway.