The study aims to present the effect of PIK3CA E542K and E545K mutations on glucose metabolism and proliferation and identify their underlying mechanisms in cervical cancer. The maximum standard uptake value (SUV_max) of tumors was detected by¹⁸F-FDG PET/CT scan. In vitro, glycolysis analysis, extracellular acidification rate analysis, and ATP production were used to evaluate the impact of PIK3CA E542K and E545K mutations on glucose metabolism. The expression level of key glycolytic enzymes was evaluated by western blotting and immunohistochemical staining in cervical cancer cells and tumor tissues, respectively. Immunofluorescence analysis was used to observe the nuclear translocation of β-catenin. The target gene of β-catenin was analyzed by using luciferase reporter system. The glucose metabolic ability of the xenograft models was assessed by SUV_max from microPET/CT scanning. Cervical cancer patients with mutant PIK3CA (E542K and E545K) exhibited a higher SUV_max value than those with wild-type PIK3CA (P = 0.037), which was confirmed in xenograft models. In vitro, enhanced glucose metabolism and proliferation was observed in SiHa and MS751 cells with mutant PIK3CA. The mRNA and protein expression of key glycolytic enzymes was increased. AKT/GSK3β/β-catenin signaling was highly activated in SiHa and MS751 cells with mutant PIK3CA. Knocking down β-catenin expression decreased glucose uptake and lactate production. In addition, the nuclear accumulation of β-catenin was found in SiHa cells and tumors with mutant PIK3CA. Furthermore, β-catenin downregulated the expression of SIRT3 via suppressing the activity of the SIRT3 promotor, and the reduced glucose uptake and lactate production due to the downregulation of β-catenin can be reversed by the transfection of SIRT3 siRNA in SiHa cells with mutant PIK3CA. The negative correlation between β-catenin and SIRT3 was further confirmed in cervical cancer tissues. These findings provide evidence that the PI3K E542K and E545K/β-catenin/SIRT3 signaling axis regulates glucose metabolism and proliferation in cervical cancers with PIK3CA mutations, suggesting therapeutic targets in the treatment of cervical cancers. FUSCC 050432–4-1212B. Registered 24 December 2012 (retrospectively registered).

Background: HPV-independent cervical cancers (HPV-ind CCs) are uncommon with worse prognosis and poorly understood. This study investigated the molecular characteristics of HPV-ind CCs, aiming to explore new strategies for HPV-ind CCs. Methods: HPV status of 1010 cervical cancer patients were detected by RT-PCR, PCR and RNA-sequencing (RNA-seq). Whole exome sequencing (WES) and RNA-seq were performed in identified HPV-ind CCs. The efficacy of PI3Kα inhibitor BYL719 in HPV-ind CCs was evaluated in cell lines, patient-derived organoids (PDOs) and patient-derived xenografts (PDXs). Results: Twenty-five CCs were identified as HPV-ind, which were more common seen in older, adenocarcinoma patients and exhibited poorer prognosis as well as higher tumor mutation burden compared to HPV-associated CCs. HPV-ind CCs were featured with highly activated PI3K/AKT signaling pathway, particularly, PIK3CA being the most predominant genomic alteration (36%). BYL719 demonstrated superior tumor suppression in vitro and in vivo. Furthermore, HPV-ind CCs were classified into two subtypes according to distinct prognosis by gene expression profiles, the metabolism subtype and immune subtype. Conclusions: This study reveals the prevalence, clinicopathology, and molecular features of HPV-ind CCs and emphasizes the importance of PIK3CA mutations and PI3K pathway activation in tumorigenesis, which suggests the potential significance of PI3Kα inhibitors in HPV-ind CC patients.

Ovarian clear cell carcinoma is a distinct histologic subtype with grave survival. The underlying molecular mechanism is not fully elucidated. However, we don’t have many cell lines, which are useful experimental tools for research. We describe the establishment and characterization of a new ovarian clear cell carcinoma cell line from a Chinese patient. FDOV1 has been subcultured for more than 80 generations. Monolayer cultured cells are polygonal in shape, showing a transparent cytoplasm full of vacuoles. The number of chromosomes ranges from 45 to 90. FDOV1 cells produces CA-125, but not CA-199. The cells could be transplanted and produced tumors mimicking the donor tumor morphologically and immunohistochemically. Whole exome sequence showed both FDOV1 and tissue block harbored PIK3CA H1047R mutation and ARID1A frameshift mutations (p.L2106 fs, p.N201 fs). More interestingly, we observed SPOP mutation (p.D82H) and ZNF217 (chromosome 20q13) amplification in FDOV1, which are quite novel. Only a few patient-derived ovarian clear cell carcinoma cell lines have been reported in the literature. FDOV1 is the very first one, to the best of our knowledge, from a Mainland Chinese patient. It showed infinite multiplication until now and tumorigenicity in vivo. FDOV1 has co-existing PIK3CA and ARID1A mutations. It also harbored SPOP mutation and ZNF217 amplification, which would probably be a good model for exploring the molecular mechanism of ovarian clear cell carcinoma.

Peritoneal implantation and lymph node metastasis have different driving mechanisms in ovarian cancer. Elucidating the underlying mechanism of lymph node metastasis is important for treatment outcomes. A new cell line, FDOVL, was established from a metastatic lymph node of a patient with primary platinum-resistant ovarian cancer and was then characterized. The effect of NOTCH1-p.C702fs mutation and NOTCH1 inhibitor on migration was evaluated in vitro and in vivo. Ten paired primary sites and metastatic lymph nodes were analyzed by RNA sequencing. The FDOVL cell line with serious karyotype abnormalities could be stably passaged and could be used to generated xenografts. NOTCH1-p.C702fs mutation was found exclusively in the FDOVL cell line and the metastatic lymph node. The mutation promoted migration and invasion in cell and animal models, and these effects were markedly repressed by the NOTCH inhibitor LY3039478. RNA sequencing confirmed CSF3 as the downstream effector of NOTCH1 mutation. Furthermore, the mutation was significantly more common in metastatic lymph nodes than in other peritoneal metastases in 10 paired samples (60% vs. 20%). The study revealed that NOTCH1 mutation is probably a driver of lymph node metastasis in ovarian cancer, which offers new ideas for the treatment of ovarian cancer lymph node metastasis with NOTCH inhibitors.

The pathogenesis of uterine carcinosarcoma (UCS) remains unclear due to a few mature cell lines. Herein, we established a new cell line, ESCA, from a Chinese woman. Especially, three sublines, named ESCA-2, ESCA-3, ESCA-5, were isolated based on the rate of cells’ different sedimentation. All ESCA cells have been subcultured for more than 60 generations. ESCA sublines display different cell morphology and growth characteristics, as well as have different sensitivity to chemotherapeutic drugs. ESCA was most sensitive to paclitaxel and carboplatin, while ESCA-2 was most sensitive to ifosfamide. Besides, ESCA showed severe chromosome karyotype abnormalities and abnormal number of chromosomes. Whole exome sequence showed ESCA and its sublines, as well as tissue block shared similar single nucleotide variants, such as TP53, TRRAP mutations, while relatively large differences in mutational signature abundance. When all ESCA cells were xenotransplanted subcutaneously into BALB/c-nu mice, they developed into tumors that resembled the original tumor with positive AE1/3 and Vimentin in immunohistochemical staining. Interestingly, the transplanted tumor from ESCA-5 proliferated fastest with a relatively low level of glucose uptake evaluated by micro-PET/CT scanning. Taken together, ESCA and its sublines may be valuable tools to explore the molecular mechanism of UCS.