Inhibition of protein arginine methyltransferase 6 activates interferon signaling and induces the apoptosis of endometrial cancer cells via histone modification

Histone modification, a major epigenetic mechanism regulating gene expression through chromatin remodeling, introduces dynamic changes in chromatin architecture. Protein arginine methyltransferase 6 (PRMT6) is overexpressed in various types of cancer, including prostate, lung and endometrial cancer (EC). Epigenome regulates the expression of endogenous retrovirus (ERV), which activates interferon signaling related to cancer. The antitumor effects of PRMT6 inhibition and the role of PRMT6 in EC were investigated, using epigenome multi‑omics analysis, including an assay for chromatin immunoprecipitation sequencing (ChIP‑seq) and RNA sequencing (RNA‑seq). The expression of PRMT6 in EC was analyzed using reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR) and immunohistochemistry (IHC). The prognostic impact of PRMT6 expression was evaluated using IHC. The effects of PRMT6‑knockdown (KD) were investigated using cell viability and apoptosis assays, as well as its effects on the epigenome, using ChIP‑seq of H3K27ac antibodies and RNA‑seq. Finally, the downstream targets identified by multi‑omics analysis were evaluated. PRMT6 was overexpressed in EC and associated with a poor prognosis. PRMT6‑KD induced histone hypomethylation, while suppressing cell growth and apoptosis. ChIP‑seq revealed that PRMT6 regulated genomic regions related to interferons and apoptosis through histone modifications. The RNA‑seq data demonstrated altered interferon‑related pathways and increased expression of tumor suppressor genes, including NK6 homeobox 1 and phosphoinositide‑3‑kinase regulatory subunit 1, following PRMT6‑KD. RT‑qPCR revealed that eight ERV genes which activated interferon signaling were upregulated by PRMT6‑KD. The data of the present study suggested that PRMT6 inhibition induced apoptosis through interferon signaling activated by ERV. PRMT6 regulated tumor suppressor genes and may be a novel therapeutic target, to the best of our knowledge, in EC.

Identification of target cells of human papillomavirus 18 using squamocolumnar junction organoids

Human papillomavirus 18 (HPV18) is a highly malignant HPV genotype among high-risk HPVs, characterized by the difficulty of detecting it in precancerous lesions and its high prevalence in adenocarcinomas. The cellular targets and molecular mechanisms underlying its infection remain unclear. In this study, we aimed to identify the cells targeted by HPV18 and elucidate the molecular mechanisms underlying HPV18 replication. Initially, we established a lentiviral vector (HPV18LCR-GFP vector) containing the HPV18 long control region promoter located upstream of EGFP. Subsequently, HPV18LCR-GFP vectors were transduced into patient-derived squamocolumnar junction organoids, and the presence of GFP-positive cells was evaluated. Single-cell RNA sequencing of GFP-positive and GFP-negative cells was conducted. Differentially expressed gene analysis revealed that 169 and 484 genes were significantly upregulated in GFP-positive and GFP-negative cells, respectively. Pathway analysis showed that pathways associated with cell cycle and viral carcinogenesis were upregulated in GFP-positive cells, whereas keratinization and mitophagy/autophagy-related pathways were upregulated in GFP-negative cells. siRNA-mediated luciferase reporter assay and HPV18 genome replication assay validated that, among the upregulated genes, ADNP, FHL2, and NPM3 were significantly associated with the activation of the HPV18 early promoter and maintenance of the HPV18 genome. Among them, NPM3 showed substantially higher expression in HPV-related cervical adenocarcinomas than in squamous cell carcinomas, and NPM3 knockdown of HPV18-infected cells downregulated stem cell-related genes. Our new experimental model allows us to identify novel genes involved in HPV18 early promoter activities. These molecules might serve as therapeutic targets in HPV18-infected cervical lesions.

Characterization of a fluorescence imaging probe that exploits metabolic dependency of ovarian clear cell carcinoma

The purpose of this study is to clarify the metabolic dependence of ovarian clear cell carcinoma (CCC) by comparing normal tissues and to examine the applicability of fluorescence imaging probe to exploit these metabolic differences. Enhanced glutathione synthesis was supported by the increased uptake of related metabolites and elevated expression levels of genes. Accumulation of intracellular iron and lipid peroxide, induction of cell death by inhibition of the glutathione synthesis pathway indicated that ferroptosis was induced. The activation of γ-glutamyl hydroxymethyl rhodamine green (gGlu-HMRG), a fluorescent imaging probe that recognizes γ-glutamyl transferase, which is essential for the synthesis of glutathione, was investigated in fresh-frozen surgical specimens. gGlu-HMRG detected extremely strong fluorescent signals in the tumor lesions of CCC patients, compared to normal ovaries or endometrium. These results revealed that CCC occurs in the stressful and unique environment of free radical-rich endometrioma, and that glutathione metabolism is enhanced as an adaptation to oxidative stress. Furthermore, a modality that exploits these metabolic differences would be useful for distinguishing between CCC and normal tissues.

Heterogeneous treatment effects of adjuvant therapy for patients with cervical cancer in the intermediate-risk group

BACKGROUND

The efficacy of adjuvant therapy for patients with cervical cancer with intermediate risk (CC-IR) remains controversial. We examined the impact of adjuvant therapy on survival outcomes in patients with CC-IR and evaluated the heterogeneous treatment effects (HTEs) of adjuvant therapies based on clinicopathologic characteristics.

METHODS

We retrospectively analyzed a previous Japanese nationwide cohort of 6192 patients with stage IB-IIB cervical cancer who underwent radical hysterectomy. We created two pairs of propensity score-matched treatment/control groups to investigate the treatment effects of adjuvant therapies: (1) adjuvant therapy versus non-adjuvant therapy; (2) chemotherapy versus radiotherapy conditional on adjuvant therapy. Multivariate analyses with treatment interactions were performed to evaluate the HTEs.

RESULTS

Among the 1613 patients with CC-IR, 619 and 994 were in the non-treatment and treatment groups, respectively. Survival outcomes did not differ between the two groups: 3-year progression-free survival (PFS) rates were 88.1% and 90.3% in the non-treatment and treatment groups, respectively (p = 0.199). Of the patients in the treatment group, 654 and 340 received radiotherapy and chemotherapy, respectively. Patients who received chemotherapy had better PFS than those who received radiotherapy (3-year PFS, 90.9% vs. 82.9%, p = 0.010). Tumor size was a significant factor that affected the treatment effects of chemotherapy; patients with large tumors gained better therapeutic effects from chemotherapy than those with small tumors.

CONCLUSION

Adjuvant therapy is optional for some patients with CC-IR; however, chemotherapy can be recommended as adjuvant therapy, particularly for patients with large tumors.

Efficacy of regional cooling + oral dexamethasone for primary prevention of hand-foot syndrome associated with pegylated liposomal doxorubicin

PURPOSE

Pegylated liposomal doxorubicin (PLD)-induced hand-foot syndrome (HFS) frequently lowers the quality of life of ovarian cancer patients. Wrist and ankle cooling, having a limited preventive effect, has been the commonest supportive HFS care. In this study, we retrospectively assessed the primary preventive effect of a combination of regional cooling and oral dexamethasone therapy (cooling + oral Dex) on HFS.

METHODS

This study is a single-arm retrospective, observational study. Recurrent ovarian cancer patients were administered PLD ± bevacizumab. We retrospectively examined the efficacy of hands and feet cooling (from the start of PLD to the end) + oral Dex (day 1-5: 8 mg/day, day 6, 7: 4 mg/day) for primary HFS prevention.

RESULTS

This study included 74 patients. The initial dose of PLD was 50 mg/m² and 40 mg/m² for 32 (43.2%) and 42 (56.8%) patients, respectively. HFS of Grade ≥ 2 and Grade ≥ 3 developed in five (6.8%) and one (1.4%) patient(s), respectively. The incidence of ≥ Grade 2 and ≥ Grade 3 HFS was much lower than those reported in previous studies. Dose reduction was required in 13 patients (17.6%) mainly because of neutropenia or mucositis; there was no HFS-induced dose reduction. Meanwhile, PLD therapy was discontinued mainly because of interstitial pneumonia (4 patients) and HFS (one patient).

CONCLUSIONS

We demonstrated the efficacy of regional cooling and oral Dex for primary prevention of PLD-induced HFS. Although future prospective studies are needed to confirm its efficacy, this combination therapy can be considered for primary prevention of HFS in ovarian cancer patients on PLD.

Cells with stem-like properties are associated with the development of HPV18-positive cervical cancer

The cellular origins of cervical cancer and the histological differentiation of human papillomavirus (HPV)-infected cells remain unexplained. To gain new insights into the carcinogenesis and histological differentiation of HPV-associated cervical cancer, we focused on cervical cancer with mixed histological types. We conducted genomic and transcriptomic analyses of cervical cancers with mixed histological types. The commonality of the cellular origins of these cancers was inferred using phylogenetic analysis and by assessing the HPV integration sites. Carcinogenesis was estimated by analyzing human gene expression profiles in different histological types. Among 42 cervical cancers with known HPV types, mixed histological types were detected in four cases, and three of them were HPV18-positive. Phylogenetic analysis of these three cases revealed that the different histological types had a common cell of origin. Moreover, the HPV-derived transcriptome and HPV integration sites were common among different histological types, suggesting that HPV integration could occur before differentiation into each histological type. Human gene expression profiles indicated that HPV18-positive cancer retained immunologically cold components with stem cell properties. Mixed cervical cancer has a common cellular origin among different histological types, and progenitor cells with stem-like properties may be associated with the development of HPV18-positive cervical cancer.

Effect of pelvic radiotherapy on patients with stage IB‑IIA cervical cancer after radical hysterectomy: A single‑center 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.

High-Throughput Functional Evaluation of MAP2K1 Variants in Cancer

Activating mutations in mitogen-activated protein kinase kinase 1 (MAP2K1) are involved in a variety of cancers and may be classified according to their RAF dependence. Sensitivity to combined BRAF and MEK treatments is associated with co-mutations of MAP2K1 and BRAF; however, the significance of less frequent MAP2K1 mutations is largely unknown. The transforming potential and drug sensitivity of 100 MAP2K1 variants were evaluated using individual assays and the mixed-all-nominated-in-one method. In addition, A375, a melanoma cell line harboring the BRAF V600E mutation, was used to evaluate the function of the MAP2K1 variants in combination with active RAF signaling. Among a total of 67 variants of unknown significance, 16 were evaluated as oncogenic or likely oncogenic. The drug sensitivity of the individual variants did not vary with respect to BRAF inhibitors, MEK inhibitors (MEKi), or their combination. Sensitivity to BRAF inhibitors was associated with the RAF dependency of the MAP2K1 variants, whereas resistance was higher in RAF-regulated or independent variants compared with RAF-dependent variants. Thus, the synergistic effect of BRAF and MEKis may be observed in RAF-regulated and RAF-dependent variants. MAP2K1 variants exhibit differential sensitivity to BRAF and MEKis, suggesting the importance of individual functional analysis for the selection of optimal treatments for each patient. This comprehensive evaluation reveals precise functional information and provides optimal combination treatment for individual MAP2K1 variants.

Application of organoid culture from HPV18-positive small cell carcinoma of the uterine cervix for precision medicine

BACKGROUND

Small cell carcinoma of the uterine cervix (SCCC) is a rare and highly malignant human papillomavirus (HPV)-associated cancer in which human genes related to the integration site can serve as a target for precision medicine. The aim of our study was to establish a workflow for precision medicine of HPV-associated cancer using patient-derived organoid.

METHODS

Organoid was established from the biopsy of a patient diagnosed with HPV18-positive SCCC. Therapeutic targets were identified by whole exome sequencing (WES) and RNA-seq analysis. Drug sensitivity testing was performed using organoids and organoid-derived mouse xenograft model.

RESULTS

WES revealed that both the original tumor and organoid had 19 somatic variants in common, including the KRAS p.G12D pathogenic variant. Meanwhile, RNA-seq revealed that HPV18 was integrated into chromosome 8 at 8q24.21 with increased expression of the proto-oncogene MYC. Drug sensitivity testing revealed that a KRAS pathway inhibitor exerted strong anti-cancer effects on the SCCC organoid compared to a MYC inhibitor, which were also confirmed in the xenograft model.

CONCLUSION

In this study, we confirmed two strategies for identifying therapeutic targets of HPV-derived SCCC, WES for identifying pathogenic variants and RNA sequencing for identifying HPV integration sites. Organoid culture is an effective tool for unveiling the oncogenic process of rare tumors and can be a breakthrough for the development of precision medicine for patients with HPV-positive SCCC.

A case of refractory pelvic squamous cell carcinoma of unknown primary that responded to nivolumab

Cancer of unknown primary (CUP) is a heterogeneous group of metastatic tumors with a usually unfavorable prognosis. A 33-year-old female was diagnosed with pelvic squamous cell carcinoma of unknown primary. The tumor was p16-positive, suggesting that it was human papillomavirus (HPV)-related. The tumor progressed for 4 months after concurrent chemoradiotherapy (initial treatment) and was refractory to paclitaxel plus carboplatin (second-line therapy). Liquid-based cancer genomic profiling identified five pathogenic variants, including Neurofibromin1 (NF1) (p.T1690Mfs*5); however, due to the lack of domestic clinical trials, the patient could not receive genome-based molecular-target therapies. Simultaneously, nivolumab was administered to the patient post its approval in Japan for CUP. The tumor responded to nivolumab, accompanied by decreased levels of tumor markers. NF1 mutations and HPV-related carcinogenesis may be associated with a favorable response to nivolumab treatment. It may therefore serve as a potential treatment against cancers of unknown primaries.

Clinical utility of Todai OncoPanel in the setting of approved comprehensive cancer genomic profiling tests in Japan

Comprehensive cancer genome profiling (CGP) has been nationally reimbursed in Japan since June 2019. Less than 10% of the patients have been reported to undergo recommended treatment. Todai OncoPanel (TOP) is a dual DNA-RNA panel as well as a paired tumor-normal matched test. Two hundred patients underwent TOP as part of Advanced Medical Care B with approval from the Ministry of Health, Labour and Welfare between September 2018 and December 2019. Tests were carried out in patients with cancers without standard treatment or when patients had already undergone standard treatment. Data from DNA and RNA panels were analyzed in 198 and 191 patients, respectively. The percentage of patients who were given therapeutic or diagnostic recommendations was 61% (120/198). One hundred and four samples (53%) harbored gene alterations that were detected with the DNA panel and had potential treatment implications, and 14 samples (7%) had a high tumor mutational burden. Twenty-two samples (11.1%) harbored 30 fusion transcripts or MET exon 14 skipping that were detected by the RNA panel. Of those 30 transcripts, 6 had treatment implications and 4 had diagnostic implications. Thirteen patients (7%) were found to have pathogenic or likely pathogenic germline variants and genetic counseling was recommended. Overall, 12 patients (6%) received recommended treatment. In summary, patients benefited from both TOP DNA and RNA panels while following the same indication as the approved CGP tests. (UMIN000033647).

The Histone Methyltransferase SETD8 Regulates the Expression of Tumor Suppressor Genes via H4K20 Methylation and the p53 Signaling Pathway in Endometrial Cancer Cells

The histone methyltransferase SET domain-containing protein 8 (SETD8), which methylates histone H4 lysine 20 (H4K20) and non-histone proteins such as p53, plays key roles in human carcinogenesis. Our aim was to determine the involvement of SETD8 in endometrial cancer and its therapeutic potential and identify the downstream genes regulated by SETD8 via H4K20 methylation and the p53 signaling pathway. We examined the expression profile of SETD8 and evaluated whether SETD8 plays a critical role in the proliferation of endometrial cancer cells using small interfering RNAs (siRNAs). We identified the prognostically important genes regulated by SETD8 via H4K20 methylation and p53 signaling using chromatin immunoprecipitation sequencing, RNA sequencing, and machine learning. We confirmed that SETD8 expression was elevated in endometrial cancer tissues. Our in vitro results suggest that the suppression of SETD8 using siRNA or a selective inhibitor attenuated cell proliferation and promoted the apoptosis of endometrial cancer cells. In these cells, SETD8 regulates genes via H4K20 methylation and the p53 signaling pathway. We also identified the prognostically important genes related to apoptosis, such as those encoding KIAA1324 and TP73, in endometrial cancer. SETD8 is an important gene for carcinogenesis and progression of endometrial cancer via H4K20 methylation.

Endometrial cancer with concomitant endometriosis is highly associated with ovarian endometrioid carcinoma: a retrospective cohort study

Background

Endometriosis is assumed to be involved in ovarian cancer development, which is called endometriosis-associated ovarian cancer (EAOC). Uterine endometrial cells may be the cell of origin of EAOC. Accumulated carcinogenic changes in the uterine endometrial cells may increase the risk of developing EAOC. To further understand the pathogenesis of EAOCs, we focused on the clinicopathological characteristics of EAOCs in endometrial cancer patients with concomitant endometriosis.

Methods

We retrospectively reviewed 376 patients who were surgically treated for stage I–III endometrial cancer. Clinicopathological characteristics were compared between patients with and without endometriosis. Furthermore, the incidence of simultaneous endometrial and ovarian cancer (SEOC) and the histological characteristics of SEOC were compared between the two groups.

Results

Among 376 patients with endometrial cancer, 51 had concomitant endometriosis. Patients with endometriosis were significantly younger and more frequently had endometrioid G1/G2 tumors than those without endometriosis. The incidence of SEOCs was significantly higher in endometrial cancer patients with endometriosis than those without it (p < 0.0001); notably, 12 of 51 endometrial cancer patients with endometriosis (24%) had SEOCs. All of the ovarian cancers in endometrial cancer patients with endometriosis were endometrioid carcinomas. Moreover, even in those without endometriosis, endometrioid carcinoma was the most common histological type of SEOC.

Conclusion

We revealed that endometrial cancer patients with endometriosis had a high probability of SEOC and that endometrioid carcinoma was the most common histological subtype of SEOC regardless of the presence of endometriosis. For patients with endometrial cancer and endometriosis, careful examination of ovarian endometriotic lesions may be important to detect EAOCs.

Performance of an artificial intelligence-based annotation algorithm for reporting cancer genomic profiling tests

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Background: Cancer genomic profiling (CGP) tests have been approved in Japan since June 2019, with the requisite that all test results be discussed by molecular tumor boards (MTBs). More than 20,000 patients in over 200 designated hospitals have taken CGP tests by December 2021. As CGP tests have entered clinical practice, streamlining decision making by MTBs and standardizing interpretation of test results and treatment recommendations have become urgent issues. Here, we evaluated the utility of Chrovis, an annotation algorithm for reporting CGP tests to support MTBs make their recommendations. Methods: We retrospectively reviewed the reporting process of all approved CGP tests done at The University of Tokyo Hospital between December 2019 and November 2021. Chrovis provided annotation for each genetic variant by incorporating biologic, clinical, and therapeutic information by referencing several public knowledge databases and using natural language processing, and generated reports using the automated program. The MTB reviewed and made any necessary changes before finalizing the report. Changes in disclosure of germline findings were made according to the recommendations of a national guideline with consideration of past and family history. Results: Of the 243 tests, 91 changes in 81 Chrovis reports (33% of all reports) were made by the MTB. The most common type of change was germline disclosure with 26 changes (29%), followed by clinical trial information in Japan (18 changes, 20%) and recommendation of the patient-proposed national basket trial with multiple targeted agents (17 changes, 19%). Changes in germline disclosure increased from June 2021, when an update to a national guideline was released, while the proportion of changes in the latter two types remained unchanged. Gene alterations that led to the highest number of changes was TP53, with 13 changes. Changes in therapeutic recommendations were frequently observed in the RAS/MAPK pathway ( BRAF, KRAS, NF1, NRAS) with 12 changes. More changes were required with a tumor-only tissue CGP panel (57 of 149) compared with a matched tumor/normal tissue CGP panel (24 of 94, p = 0.04), mostly due to germline disclosure (24 vs. 2 changes). Conclusions: We observed that automated algorithm-based reporting was sufficient in 67% of reports. Recommendation for germline disclosure still requires manual supervision, particularly with tumor-only tissue CGP panels if algorithms do not incorporate medical history. The process of recommending clinical trials needs improvement, e.g., standardizing database formats for inclusion and exclusion criteria.

Effect of primary prophylaxis with pegfilgrastim in endometrial cancer patients treated with doxorubicin and cisplatin

OBJECTIVE

Although the incidence of febrile neutropenia (FN) is relatively higher for doxorubicin and cisplatin combination regimen than for other regimens in endometrial cancer, evidence regarding the efficacy of pegfilgrastim in this regimen is lacking.

MATERIALS AND METHODS

We retrospectively reviewed the data of 58 patients with endometrial cancer who were treated with doxorubicin plus cisplatin. The patients were divided into primary prophylaxis and non-prophylaxis groups. We compared the incidence of FN and neutropenia as well as the chemotherapy relative dose intensity (RDI) and usage of antibiotics between the groups.

RESULTS

The rates of FN (8.0% vs. 34.8%) and grade 4 neutropenia (12.0% vs. 87.0%) were significantly lower in the primary prophylaxis group. Although there was no difference in the RDI between the groups, the primary prophylaxis group had a lower rate of antibiotic prescriptions.

CONCLUSION

Prophylaxis with pegfilgrastim efficiently prevented FN in patients treated with doxorubicin and cisplatin.

Discrepancies in pathological diagnosis of endometrial stromal sarcoma: a multi-institutional retrospective study from the Japanese Clinical Oncology Group

Endometrial stromal sarcoma (ESS) is a rare uterine malignancy that requires accurate pathological diagnosis for proper treatment. This study aimed to clarify the discrepancies in the pathological diagnosis of ESS and obtain practical clues to improve diagnostic accuracy. Between 2002 and 2015, 148 patients with low-grade ESS (LGESS), high-grade ESS (HGESS), undifferentiated endometrial sarcoma (UES), or undifferentiated uterine sarcoma (UUS) diagnosed at 31 institutions were included. We performed immunohistochemistry, real-time polymerase chain reaction for JAZF1-SUZ12 and YWHAE-NUTM2A/B, and break-apart fluorescent in situ hybridization for JAZF1, PHF1, and YWHAE. Central pathology review (CPR) was performed by six pathologists. After CPR, LGESS, HGESS, UES/UUS, and other diagnoses were confirmed in 72, 25, 16, and 31 cases, respectively. Diagnostic discrepancies were observed in 19.6% (18/92) of LGESS and 34% (18/53) of HGESS or UUS/UES. Adenosarcomas, endometrial carcinomas, carcinosarcomas, and leiomyosarcomas were common diagnostic pitfalls. JAZF1-SUZ12 transcript, PHF1 split signal, and YWHAE-NUTM2A/B transcript were mutually exclusively detected in 23 LGESS, 3 LGESS, and 1 LGESS plus 3 HGESS, respectively. JAZF1-SUZ12 and YWHAE-NUTM2A/B transcripts were detected only in cases with CPR diagnosis of LGESS or HGESS. The CPR diagnosis of LGESS, HGESS, and UUS was a significant prognosticator, and patients with LGESS depicted a favorable prognosis, while those with UUS showed the worst prognosis. Pathological diagnosis of ESS is often challenging and certain tumors should be carefully considered. The accurate pathological diagnosis with the aid of molecular testing is essential for prognostic prediction and treatment selection.

Genetic diagnosis of pseudomyxoma peritonei originating from mucinous borderline tumor inside an ovarian teratoma

Background

Pseudomyxoma peritonei is a rare disease condition mainly caused by primary mucinous tumors from the appendix and rarely from the ovary, such as when mucinous ovarian tumors arise from within a teratoma. Molecular analyses of pseudomyxoma from the appendix showed that KRAS and GNAS pathogenic variants are common genetic features of pseudomyxoma peritonei. However, the origin of the tumors is difficult to be identified via genetic variants alone. This study presents a case of pseudomyxoma peritonei of ovarian origin, which was diagnosed by comprehensive genomic profiling with ploidy analysis in a series of primary, recurrent, and autopsy tumor specimens.

Case presentation

A 40-year-old woman was diagnosed with Stage IC2 mucinous ovarian tumor of borderline malignancy with mature cystic teratoma, upon clinical pathology. Immunohistochemical analysis suggested that the mucinous tumor was derived from the intestinal component of an ovarian teratoma. Three years later, intraperitoneal recurrence was detected, which subsequently progressed to pseudomyxoma peritonei. Genomic analysis detected KRAS (G12D), GNAS (R201C), and FBXW7 (R367*) variants in the primary tumor. In addition, the tumor showed aneuploidy with loss of heterozygosity (LOH) in all its chromosomes, which suggested that the primary ovarian tumor was derived from germ cells. Existence of one Barr body suggested the existence of uniparental disomy of the tumors throughout the genome, instead of a haploid genotype. All three pathogenic variants remained positive in the initial recurrent tumor, as well as in the paired DNA from the whole blood in pseudomyxoma peritonei. The pathogenic variant of KRAS (G12D) was also identified in the autopsy specimen of the appendix by droplet digital polymerase chain reaction.

Conclusions

This study pathologically and genetically confirmed that the primary ovarian borderline tumor was derived from the intestinal component of an ovarian teratoma, and that the subsequent pseudomyxoma peritonei progressed from the primary ovarian tumor. Integrative genomic analysis was useful to identify cellular origin of tumors, as well as to precisely interpret the process of disease progression.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12920-022-01188-x.

Histone arginine methyltransferase CARM1 selective inhibitor TP-064 induces apoptosis in endometrial cancer

Histone modification is the key epigenetic mechanism that regulates gene expression. Coactivator-associated arginine methyltransferase 1 (CARM1) is an arginine methyltransferase that catalyzes dimethylation of histone H3 (H3R17) at arginine 17. Lately, it has been suggested that CARM1 is associated with human carcinogenesis, and the CARM1-selective inhibitor, TP-064, has been shown to be a potential therapeutic agent for multiple myeloma. However, the physiological significance of CARM1 in endometrial cancer remains unclear. Therefore, we aimed to explore the role of CARM1 and the effect of TP-064 in endometrial cancer. To this end, we analyzed CARM1 expression in endometrial cancer using quantitative real-time polymerase chain reaction and examined the antitumor mechanism with CARM1 knockdown endometrial cancer cells. Moreover, we evaluated the therapeutic capability of TP-064 in endometrial cancer cells. CARM1 was remarkably overexpressed in 52 endometrial cancer tissues compared to normal endometrial tissues. The growth of CARM1 knockdown endometrial cancer cells was suppressed and CARM1 knockdown induced apoptosis. TP-064 also inhibited endometrial cancer cell growth and declined the number of endometrial cancer cell colonies. These data suggest that CARM1 may be a powerful therapeutic target for endometrial cancer.

Recurrent malignant melanoma of the uterine cervix treated with anti-PD-1 antibodies and anti-CTLA-4 antibodies: A case report

In 5% of female patients with malignant melanoma (MM), MM develops from the genital tract. MM of the cervix is particularly rare. In the present case report, a 73-year-old woman with stage ⅢC cervical MM underwent modified radical hysterectomy, bilateral salpingo-oophorectomy and pelvic lymph node dissection. A total of 4 months after surgery, multiple metastases were found in the brain, lung, liver, lymph nodes and bone. The patient underwent γ-knife surgery of the brain and received treatment with anti PD-1 antibodies (nivolumab) and anti-CTLA4 antibodies (ipilimumab); however, they were ineffective and the patient subsequently died. To the best of our knowledge, this is the first report of treatment using two types of immune checkpoint inhibitors administered to a patient with cervical MM. Taken together with previous reports, this case suggests that immune checkpoint inhibitors may be less effective in cervical MM than in cutaneous MM; however, the number of cases is small. Further development of biomarkers to stratify efficacy is required.

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.

History of whole pelvis plus para-aortic radiation is a risk factor associated with febrile neutropenia during chemotherapy for recurrent cervical cancer

BACKGROUND

Radiation-based therapy is widely used for advanced cervical cancer. Prior radiation-based therapy is a potential risk factor for febrile neutropenia (FN). However, the effect of irradiation field size on the incidence of FN during recurrent cervical cancer treatment is unclear. This study aimed to investigate the relationship between prior irradiation field size and FN development during recurrent chemotherapy.

METHODS

This retrospective, observational study included cervical cancer patients who received recurrent chemotherapy between November 2006 and June 2020. The patients were classified into two groups based on the area of irradiation fields. The first group included patients with a history of whole pelvis (WP) irradiation (WP group). The second group had patients who underwent WP plus para-aortic lymph node (PAN) irradiation (WP + PAN group). The incidences of hematological toxicities and FN during the recurrent chemoradiotherapy were compared between the two groups.

RESULTS

The FN incidence was significantly higher in the WP + PAN group than in the WP group (32.1% vs. 0%, P < 0.001). The incidence of Grade 4 neutropenia was not significantly different between the WP + PAN and WP groups. The nadir absolute neutrophil counts were significantly lower and the dose reduction or discontinuation rate of chemotherapy was significantly higher in the WP + PAN group than in the WP group.

CONCLUSION

History of WP plus PAN radiation is a risk factor for developing FN during recurrent cervical cancer chemotherapy.

A randomized phase II/III trial of conventional paclitaxel and carboplatin with or without bevacizumab versus dose-dense paclitaxel and carboplatin with or without bevacizumab, in stage IVB, recurrent, or persistent cervical carcinoma (JCOG1311): Primary analysis

OBJECTIVE

To assess the efficacy and safety of dose-dense weekly paclitaxel plus carboplatin (ddTC) with or without bevacizumab compared to conventional, tri-weekly paclitaxel plus carboplatin (cTC) with or without bevacizumab, in metastatic or recurrent cervical carcinoma not amenable to curative local therapy.

METHODS

Patients were randomly assigned to either the cTC or ddTC arm. The cTC regimen was paclitaxel 175 mg/m² and carboplatin at an area under the curve (AUC) of 5 on day 1. The ddTC regimen was paclitaxel 80 mg/m² on day 1, 8, 15 and carboplatin at AUC of 5 on day 1. Both cTC and ddTC treatments were repeated every 3 weeks for up to 9 cycles. After bevacizumab was approved in Japan, patients in both arms received bevacizumab 15 mg/kg if not contraindicated. The primary endpoint of phase II part was response rate (RR). If the RR of ddTC+bevacizumab was found to be at least 5% better than to cTC + bevacizumab, the study would proceed to phase III part, which had overall survival as its primary endpoint.

CLINICAL TRIAL INFORMATION

jRCTs031180007.

RESULTS

In total, 122 patients were randomly assigned to either the cTC arm (cTC + bevacizumab: 32; cTC:29) or the ddTC arm (ddTC+bevacizumab: 30; ddTC:31). The RR for patients on cTC + bevacizumab was 67.9%, and for patients on ddTC+bevacizumab 60.7%, cTC: 55.2%, and ddTC: 50.0%.

CONCLUSIONS

The study did not meet the primary endpoint of phase II portion. Dose-dense, weekly paclitaxel plus carboplatin is not promising for metastatic or recurrent cervical carcinoma.

Application of artificial intelligence in gynecologic malignancies: A review

With the development of machine learning and deep learning models, artificial intelligence is now being applied to the field of medicine. In oncology, the use of artificial intelligence for the diagnostic evaluation of medical images such as radiographic images, omics analysis using genome data, and clinical information has been increasing in recent years. There have been increasing numbers of reports on the use of artificial intelligence in the field of gynecologic malignancies, and we introduce and review these studies. For cervical and endometrial cancers, the evaluation of medical images, such as colposcopy, hysteroscopy, and magnetic resonance images, using artificial intelligence is frequently reported. In ovarian cancer, many reports combine the assessment of medical images with the multi-omics analysis of clinical and genomic data using artificial intelligence. However, few study results can be implemented in clinical practice, and further research is needed in the future.

Enhanced antitumor activity of combined lipid bubble ultrasound and anticancer drugs in gynecological cervical cancers

Chemotherapy plays an important role in the treatment of patients with gynecological cancers. Delivering anticancer drugs effectively to tumor cells with just few side effects is key in cancer treatment. Lipid bubbles (LB) are compounds that increase the vascular permeability of the tumor under diagnostic ultrasound (US) exposure and enable the effective transport of drugs to tumor cells. The aim of our study was to establish a novel drug delivery technique for chemotherapy and to identify the most effective anticancer drugs for the bubble US‐mediated drug delivery system (BUS‐DDS) in gynecological cancer treatments. We constructed xenograft models using cervical cancer (HeLa) and uterine endometrial cancer (HEC1B) cell lines. Lipid bubbles were injected i.v., combined with either cisplatin (CDDP), pegylated liposomal doxorubicin (PLD), or bevacizumab, and US was applied to the tumor. We compared the enhanced chemotherapeutic effects of these drugs and determined the optimal drugs for BUS‐DDS. Tumor volume reduction of HeLa and HEC1B xenografts following cisplatin treatment was significantly enhanced by BUS‐DDS. Both CDDP and PLD significantly enhanced the antitumor effects of BUS‐DDS in HeLa tumors; however, volume reduction by BUS‐DDS was insignificant when combined with bevacizumab, a humanized anti‐vascular endothelial growth factor mAb. The BUS‐DDS did not cause any severe adverse events and significantly enhanced the antitumor effects of cytotoxic drugs. The effects of bevacizumab, which were not as dose‐dependent as those of the two drugs used prior, were minimal. Our data suggest that BUS‐DDS technology might help achieve “reinforced targeting” in the treatment of gynecological cancers.

Automated system for diagnosing endometrial cancer by adopting deep-learning technology in hysteroscopy

Endometrial cancer is a ubiquitous gynecological disease with increasing global incidence. Therefore, despite the lack of an established screening technique to date, early diagnosis of endometrial cancer assumes critical importance. This paper presents an artificial-intelligence-based system to detect the regions affected by endometrial cancer automatically from hysteroscopic images. In this study, 177 patients (60 with normal endometrium, 21 with uterine myoma, 60 with endometrial polyp, 15 with atypical endometrial hyperplasia, and 21 with endometrial cancer) with a history of hysteroscopy were recruited. Machine-learning techniques based on three popular deep neural network models were employed, and a continuity-analysis method was developed to enhance the accuracy of cancer diagnosis. Finally, we investigated if the accuracy could be improved by combining all the trained models. The results reveal that the diagnosis accuracy was approximately 80% (78.91–80.93%) when using the standard method, and it increased to 89% (83.94–89.13%) and exceeded 90% (i.e., 90.29%) when employing the proposed continuity analysis and combining the three neural networks, respectively. The corresponding sensitivity and specificity equaled 91.66% and 89.36%, respectively. These findings demonstrate the proposed method to be sufficient to facilitate timely diagnosis of endometrial cancer in the near future.

Targeting Epigenetic Regulators for Endometrial Cancer Therapy: Its Molecular Biology and Potential Clinical Applications

Endometrial cancer is one of the most frequently diagnosed gynecological malignancies worldwide. However, its prognosis in advanced stages is poor, and there are only few available treatment options when it recurs. Epigenetic changes in gene function, such as DNA methylation, histone modification, and non-coding RNA, have been studied for the last two decades. Epigenetic dysregulation is often reported in the development and progression of various cancers. Recently, epigenetic changes in endometrial cancer have also been discussed. In this review, we give the main points of the role of DNA methylation and histone modification in endometrial cancer, the diagnostic tools to determine these modifications, and inhibitors targeting epigenetic regulators that are currently in preclinical studies and clinical trials.

A low preoperative albumin-to-globulin ratio is a negative prognostic factor in patients with surgically treated cervical cancer

BACKGROUND

The albumin-to-globulin ratio reflects both the nutrition and inflammation and predicts prognosis in patients with various malignancies. However, in cervical cancer patients who undergo surgery, its significance has yet to be established.

METHODS

A total of 247 cervical cancer patients who received surgical treatment at our institution between 2005 and 2017 were enrolled in this study. Preoperative data, such as the levels of serum albumin and serum globulin as well as the albumin-to-globulin ratio along with the other clinicopathological characteristics were retrospectively assessed, and their association with the overall survival was analyzed.

RESULTS

Overall, 49 cases of recurrence and 26 deaths were observed during the median follow-up time of 58.6 months. A low albumin-to-globulin ratio (< 1.345) as well as low albumin (< 3.25 g/dL) and high globulin levels (≥ 3.25 g/dL) were significantly associated with poor prognosis. According to the multivariate analysis, a low albumin-to-globulin ratio was an independent prognostic factor for overall survival (HR = 2.59, 95% CI 1.12-5.96, P = 0.026); however, low albumin or high globulin levels was not associated with the overall survival. Among the clinicopathological characteristics, older age, diabetes mellitus, hypertension, larger tumor size, and parametrial invasion were associated with a low albumin-to-globulin ratio.

CONCLUSION

A low albumin-to-globulin ratio was associated with a poor prognosis in patients with surgically treated invasive cervical cancer. Therefore, the albumin-to-globulin ratio may serve as a prognostic marker, which predicts a worse prognosis.

Lymphadenectomy issues in endometrial cancer

Objectives

This review aims to introduce preoperative scoring systems to predict lymph node metastasis (LNM) and ongoing clinical trials to investigate the therapeutic role of lymphadenectomy for endometrial cancer.

Methods

We summarized previous reports on the preoperative prediction models for LNM and evaluated their validity to omit lymphadenectomy in our recent cohorts. Next, we compared characteristics of two ongoing lymphadenectomy trials (JCOG1412, ECLAT) to examine the survival benefit of lymphadenectomy in endometrial cancer, and described the details of JCOG1412.

Results

Lymphadenectomy has been omitted for 64 endometrial cancer patients who met low-risk criteria to omit lymphadenectomy using our scoring system (LNM score) and no lymphatic failure has been observed. Other two models also produced comparable results. Two randomized phase III trials to evaluate survival benefit of lymphadenectomy are ongoing for endometrial cancer. JCOG1412 compares pelvic lymphadenectomy alone with pelvic and para-aortic lymphadenectomy to evaluate the therapeutic role of para-aortic lymphadenectomy for patients at risk of LNM. For quality assurance of lymphadenectomy, we defined several regulations, including lower limit of the number of resected nodes, and submission of photos of dissected area to evaluate thoroughness of lymphadenectomy in the protocol. The latest monitoring report showed that the quality of lymphadenectomy has been well-controlled in JCOG1412.

Conclusion

Our strategy seems reasonable to omit lymphadenectomy and could be generalized in clinical practice. JCOG1412 is a high-quality lymphadenectomy trial in terms of the quality of surgical procedures, which would draw the bona-fide conclusions regarding the therapeutic role of lymphadenectomy for endometrial cancer.

Desensitization strategy for hypersensitivity reactions to carboplatin in five patients with gynecological cancer

AIM

Carboplatin is a key drug for gynecologic cancers. However, hypersensitivity reactions (HSR) are major adverse effects that might necessitate carboplatin discontinuation. Desensitization is an effective method in patients who developed initial HSR and further required carboplatin treatment. Here, we aimed to evaluate our experience with the use of the carboplatin desensitization protocol in five patients at the University of Tokyo Hospital.

METHODS

We established a four-step, 5-h desensitization protocol for our hospital. Observational and retrospective analyses were performed. Additionally, we have shared the patients' clinical information with the emergency department to ensure the safety of this protocol.

RESULTS

Five patients with recurrent gynecological cancer were treated using this protocol. Four of the five patients were treated effectively and 28 of 29 desensitization protocols were completed successfully. In one patient, we switched to olaparib successfully after two courses of our protocol. One patient who developed grade 4 HSR during initial carboplatin administration developed grade 2 HSR and we discontinued the protocol.

CONCLUSION

The carboplatin desensitization protocol is very efficient. The outcome of our protocol was on a par with other protocols. To the best of our knowledge, this is the first study to indicate that switching to olaparib can be considered a suitable option in patients who develop HSR to carboplatin.

The histone methyltransferase SMYD2 is a novel therapeutic target for the induction of apoptosis in ovarian clear cell carcinoma cells

Previous studies have suggested that histone methylation can modulate carcinogenesis and cancer progression. For instance, the histone methyltransferase SET and MYND domain containing 2 (SMYD2) is overexpressed in several types of cancer tissue. The aim of the present study was to determine whether SMYD2 could serve a therapeutic role in ovarian clear cell carcinoma (OCCC). Reverse transcription-quantitative PCR was used to examine SMYD2 expression in 23 clinical OCCC specimens. Moreover, OCCC cell proliferation and cell cycle progression were also examined following small interfering RNA-mediated SMYD2 silencing or treatment with a selective SMYD2 inhibitor. SMYD2 was significantly upregulated in clinical OCCC specimens, compared with normal ovarian tissue. In addition, SMYD2 knockdown decreased cell viability as determined via a Cell Counting Kit-8 assay. Moreover, the proportion of cells in the sub-G₁ phase increased following SMYD2 knockdown, suggesting increased apoptosis. Treatment with the SMYD2 inhibitor LLY-507 suppressed OCCC cell viability. These results suggested that SMYD2 could promote OCCC viability, and that SMYD2 inhibition induced apoptosis in these cells. Thus, SMYD2 inhibitors may represent a promising molecular targeted approach for OCCC treatment.

Effect of murine double-minute 2 inhibitors in preclinical models of advanced clear cell carcinomas originating from ovaries and kidneys

Advanced clear cell carcinomas originating from both ovaries and kidneys with cancerous peritonitis have poor prognoses. Murine double-minute 2 (MDM2) is a potential therapeutic target for clear cell ovarian carcinomas with WT TP53. Herein, we characterized the antiangiogenic and antitumor effects of the MDM2 inhibitors DS-3032b and DS-5272 in 6 clear cell ovarian carcinoma cell lines and 2 clear cell renal carcinoma cell lines, as well as in clear cell ovarian carcinomas s.c. xenograft and ID8 (murine ovarian cancer cells with WT TP53) cancer peritonitis mouse models. In clear cell ovarian carcinoma s.c. xenograft mouse models, DS-3032b significantly reduced WT TP53 clear cell ovarian carcinoma- and clear cell renal carcinoma-derived tumor volumes. In ID8 mouse models, DS-5272 significantly inhibited ascites production, reduced body weight, and significantly improved overall survival. Additionally, DS-5272 reduced the tumor burden of peritoneal dissemination and decreased CD31⁺ cells in a dose-dependent manner. Furthermore, DS-5272 significantly decreased vascular endothelial growth factor concentrations in both sera and ascites. Combined therapy with MDM2 inhibitors and everolimus showed synergistic, and dose-reduction potential, for clear cell carcinoma treatment. Our findings suggest that MDM2 inhibitors represent promising molecular targeted therapy for clear cell carcinomas, thereby warranting further studies to evaluate the efficacy and safety of dual MDM2/mTOR inhibitors in clear cell carcinoma patients.

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.

NGS-based molecular profiling (a multi-center collaborative, observation study in Japan) highlights pathogenic variants of DNA-repair genes in advanced or recurrent endometrial cancer

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Background: Although tumor molecular profiling has now become prevalent, next-generation sequencing (NGS)-based molecular profiling with adequate annotation is limited in recurrent endometrial cancers. We investigated the frequency of alterations in cancer-related genes in a Japanese cohort of incurable endometrial cancer patients. Methods: We enrolled 102 endometrial cancer patients, who had discontinued standard therapy, and extracted tumor DNA from their formalin-fixed paraffin-embedded specimens. Oncomine Comprehensive Assay v3 (ThermoFisher), which covers 161 cancer genes, was used as a comprehensive NGS assay. We only defined variants with the annotations “pathogenic” or “likely pathogenic.” Oncogenicity and actionability were defined with the Oncomine Knowledgebase and “Chrovis database” ( https://chrov.is/ ). The protocol was approved by the institutional ethics committee at each institute, and written informed consent was obtained from all patients before enrollment. Results: The ratios of pathogenic mutations in the PI3K-AKT pathway were 34.3%, 15.7%, and 3.9% for PIK3CA, PTEN, and AKT1, while those in the receptor tyrosine kinase-RAS-MAPK pathway were 3.9%, 2.0%, 3.9%, and 1.0% for FGFR2, KRAS, NF1, and BRAF, respectively. The pathogenic mutation ratios of TP53, ATM, CTNNB1, and FBXW7 were 21.6%, 3.9%, 10.8%, and 9.8%, respectively. In addition to 5.9% of MSH2 variants (five patients with 5-20% and one patient with 56% variant allele frequency (VAF)), pathogenic variants of BRCA1 and/or BRCA2 were identified in 7.8% (seven patients with 5-20% and one with 40% VAFs). Three fusion genes were identified in three patients ( TPR- NTRK1, ESR1- CCDC170, and TBL1XR1- PIK3CA). “Actionable” gene variants (applicable for clinical trials or approved drug available in Japan) were identified in 49.0% of patients. Candidate drugs for patients with actionable variants included ROS1/TRK, AKT, immune checkpoint, and PARP inhibitors. Conclusions: Molecular profiling in poor-prognostic endometrial cancer highlighted the significance of DNA-repair related genes ( TP53, ATM, BRCA1, and BRCA2) and Wnt-beta catenin signaling pathway, and the infrequent alterations in PTEN and KRAS genes, although PIK3CA was frequently mutated. Our data suggest that targeting DNA repair pathway (including PARP inhibitors), may be a treatment option in certain endometrial cancer patients. Clinical trial information: UMIN000027294.

A randomized phase II/III trial of conventional paclitaxel and carboplatin with/without bevacizumab versus dose-dense paclitaxel and carboplatin with/without bevacizumab, in stage IVB, recurrent, or persistent cervical carcinoma (JCOG1311): Results of the phase II part

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Background: A randomized controlled trial was conducted to assess the efficacy and safety of dose-dense, weekly paclitaxel plus carboplatin (ddTC) with or without bevacizumab (Bmab) compared to conventional, tri-weekly paclitaxel plus carboplatin (cTC) with or without Bmab, in metastatic or recurrent cervical carcinoma not amenable to curative treatments with local therapy. Methods: Patients were randomly assigned to either a cTC or a ddTC regimen. After Bmab was approved in Japan (in May 2016) the protocol was amended, and patients on both arms received Bmab if not contraindicated. The cTC was paclitaxel 175 mg/m2 intravenously (IV) for 3 h on day 1 followed by carboplatin at an area under the curve of five IV for 1 h on day 1. The ddTC was paclitaxel 80 mg/m2 IV for 1 h on day 1 followed by carboplatin at an area under the curve of five IV for 1 h on day 1 and paclitaxel 80 mg/m2 IV for 1 h on day 8 and day 15. Both cTC and ddTC treatments were repeated every three weeks, for up to nine cycles. Bmab 15 mg/kg IV was repeated until progression or unacceptable toxicity. The primary endpoint of phase II was the response rate (RR) in patients with measurable lesion, who had received Bmab. If the RR of the ddTC + Bmab arm was greater than that of the cTC + Bmab arm for more than 5%, the study would proceed to phase III, which had overall survival (OS) as its primary endpoint. The planned sample size in the phase II part was 56 to select the ddTC arm with a probability of at least 75% if the difference of RR was 15% or more (45% vs. 60%). Results: Patient accrual started in October 2015. It was suspended in May 2019 because the number of Bmab-treated patients with measurable lesions reached 56. In total, 122 patients were enrolled and randomly assigned to either the cTC arm (cTC: 29 patients; cTC + Bmab: 32 patients) or the ddTC arm (ddTC: 30 patients; ddTC + Bmab: 31 patients). The primary analysis of the phase II part was conducted in November 2019. The RRs of each regimen were 67.9% [95% CI, 47.7-84.1] (19/28, cTC + Bmab), 60.7% [40.6-78.5] (17/28, ddTC + Bmab), 55.2% [35.7-73.6] (16/29, cTC), and 50.0% [29.9-70.1] (13/26, ddTC). Conclusions: The study did not meet the primary endpoint of phase II. Dose-dense, weekly paclitaxel plus carboplatin is not promising for metastatic or recurrent cervical carcinoma. Clinical trial information: jRCTs031180007.

Interleukin-17 is associated with expression of programmed cell death 1 ligand 1 in ovarian carcinoma

The programmed cell death 1/programmed cell death 1 ligand 1 pathway was successfully targeted in cancer immunotherapy. Elevated interleukin-17 (IL-17), which is known in autoimmune diseases, has recently been recognized in cancer patients. We investigated the role of IL-17 in the regulation of expression of programmed cell death 1 ligand 1 in ovarian cancer by evaluating changes in the number of IL-17-producing cluster of differentiation 4 helper T cells (Th17) and γδT cells (γδT17) in PBMC of 52 gynecological cancer patients (including 30 ovarian cancer patients) and 18 healthy controls. The occupancy ratio of Th17 and γδT17 was higher in ovarian cancer and endometrial cancer patients than in controls, determined by multi-color flow cytometry (Th17: P < 0.0001 and P = 0.0002, respectively; γδT17: P = 0.0020 and P = 0.0084, respectively). IL-17 mRNA level was elevated in PBMC of ovarian cancer patients (P = 0.0029), as measured by RT-PCR. The neutrophil-to-lymphocyte ratio, which is a prognostic biomarker of ovarian cancer, correlated with Th17 occupancy ratio in patients (P = 0.0068). We found that programmed cell death 1 ligand 1 expression and its associated factors (IL-6 and phospho-signal transducer and activator of transcription 3) were induced by IL-17 in an ovarian cancer cell line. These results suggest that increased Th17 counts and IL-17 level, which correlated with high neutrophil-to-lymphocyte ratio and programmed cell death 1 ligand 1 expression, are potential biomarkers for poor prognosis in ovarian cancer and likely indications for application of programmed cell death 1 ligand 1 pathway inhibitors.

Anti-tumor activity of dual inhibition of phosphatidylinositol 3-kinase and MDM2 against clear cell ovarian carcinoma

INTRODUCTION

PI3K pathway signaling has received attention as a molecular target in clear cell ovarian carcinoma (CCOC). MDM2 is one of the AKT effectors in the PI3K pathway, which binds to and degrades p53. In this study, we aimed to clarify the prognostic significance of PIK3CA and MDM2 expression, and potential therapeutic effect of a dual inhibition of the PI3K pathway and MDM2.

MATERIALS AND METHODS

cDNA expression was evaluated by using microarray data using 75 samples of CCOC. DS-7423 (dual inhibitor of pan-PI3K and mTOR) and RG7112 (MDM2 inhibitor) were used on CCOC cell lines to evaluate cell proliferation, expression level of MDM2 related proteins, and apoptosis by MTT assay, western blotting, and flow cytometry. DS-7423 (3 mg/kg) and/or RG7112 (50 mg/kg) were orally administrated every day for three weeks, and the anti-tumor effect was evaluated using tumor xenografts, along with immunohistochemistry.

RESULTS

Tumors with high expression of both PIK3CA and MDM2 showed significantly worse prognosis in expression array of 71 CCOCs (P = 0.013). Dual inhibition of the PI3K pathway by DS-7423 and MDM2 by RG7112 showed synergistic anti-proliferative effect in 4 CCOC cell lines without TP53 mutations. The combination therapy more robustly induced pro-apoptotic proteins (PUMA and cleaved PARP) with increase of sub G1 population and apoptotic cells, compared with either single agent alone. The combination therapy significantly reduced tumor volume in mice (P < 0.001 in OVISE, and P = 0.038 in RMG-I) without severe body weight loss. Immunohistochemistry from the xenograft tumors showed that the combination treatment significantly reduced vascularity and cell proliferation, with an increase of apoptotic cell death.

CONCLUSION

A combination therapy targeting the PI3K pathway and MDM2 might be a promising therapeutic strategy in CCOC.

Determination of eligibility criteria for salvage hysterectomy after definitive radiotherapy/concurrent chemoradiotherapy for residual cervical disease

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Background: Patients with persistent cervical cancer after definitive radiotherapy/concurrent chemoradiotherapy (RT/CCRT) have a poor prognosis. Salvage hysterectomy (HT) is potentially curative, but eligibility criteria therefor have not been determined. Methods: Part 1) Retrospective review of patients with persistent cervical cancer treated with definitive RT/CCRT at 35 institutions of the Japanese Clinical Oncology Group (JCOG) from 2005–2014. Differences between a salvage HT group and a systemic chemotherapy (CT) group after definitive RT/CCRT for residual tumor were evaluated. Clinical variables influencing a salvage HT treatment decision were evaluated using logistic regression analysis. Part 2) Questionnaire-based survey conducted by JCOG gynecologic oncologists assessing treatment choice for patients with residual cervical disease after definitive RT/CCRT. Patients with residual cervical tumor before, during and after definitive RT/CCRT were surveyed for 86 conditions and appropriate candidates for salvage HT were evaluated using heat map analysis. Results: Part 1) We identified 298 patients who underwent salvage HT or systemic CT. Median overall survival was 3.8 and 0.9 year in the HT and CT groups, respectively (HR 0.4341, 95% CI 0.336-0.559, p < 0.01). FIGO stage and lymph node metastasis at initial treatment, performance status (PS) at diagnosis of residual cervical tumor and parametrial invasion of residual cervical tumor significantly influenced a salvage HT treatment decision. Part 2) Heat map analysis showed that surveyed variables segregated into 3 groups: i) in favor of salvage HT, ii) in favor of systemic CT, and iii) either. Conditions such as FIGO stage IB-IIB, PS of 0-1, residual tumor < 4 cm, no parametrial invasion and no residual lymph node metastasis were included in group i, in favor of salvage HT. Conclusions: Eligibility criteria could be determined based on the results of the current study, and a prospective clinical trial evaluating the survival benefit of salvage HT for residual cervical tumor after definitive RT/CCRT is being planned by JCOG.

The histone methyltransferase WHSC1 is regulated by EZH2 and is important for ovarian clear cell carcinoma cell proliferation

Background

Wolf-Hirschhorn syndrome candidate gene-1 (WHSC1), a histone methyltransferase, has been found to be upregulated and its expression to be correlated with expression of enhancer of zeste homolog 2 (EZH2) in several cancers. In this study, we evaluated the role of WHSC1 and its therapeutic significance in ovarian clear cell carcinoma (OCCC).

Methods

First, we analyzed WHSC1 expression by quantitative PCR and immunohistochemistry using 23 clinical OCCC specimens. Second, the involvement of WHSC1 in OCCC cell proliferation was evaluated by MTT assays after siRNA-mediated WHSC1 knockdown. We also performed flow cytometry (FACS) to address the effect of WHSC1 on cell cycle. To examine the functional relationship between EZH2 and WHSC1, we knocked down EZH2 using siRNAs and checked the expression levels of WHSC1 and its histone mark H3K36m2 in OCCC cell lines. Finally, we checked WHSC1 expression after treatment with the selective inhibitor, GSK126.

Results

Both quantitative PCR and immunohistochemical analysis revealed that WHSC1 was significantly overexpressed in OCCC tissues compared with that in normal ovarian tissues. MTT assay revealed that knockdown of WHSC1 suppressed cell proliferation, and H3K36me2 levels were found to be decreased in immunoblotting. FACS revealed that WHSC1 knockdown affected the cell cycle. We also confirmed that WHSC1 expression was suppressed by EZH2 knockdown or inhibition, indicating that EZH2 is upstream of WHSC1 in OCCC cells.

Conclusions

WHSC1 overexpression induced cell growth and its expression is, at least in part, regulated by EZH2. Further functional analysis will reveal whether WHSC1 is a promising therapeutic target for OCCC.

Electronic supplementary material

The online version of this article (10.1186/s12885-019-5638-9) contains supplementary material, which is available to authorized users.

Histone methyltransferase SMYD2 selective inhibitor LLY-507 in combination with poly ADP ribose polymerase inhibitor has therapeutic potential against high-grade serous ovarian carcinomas

Dysfunction of histone methylation is known to be related to cancer progression. The histone methyltransferase SMYD2 methylates histone protein H3 and non-histone proteins, including poly ADP ribose polymerase 1 (PARP1). There have been reports of SMYD2 overexpression in several types of cancers. However, there are no reports regarding its role in high-grade serous ovarian carcinomas (HGSOCs). Therefore, we investigated the expression profile and conducted functional analysis on SMYD2 in HGSOC cells. In addition, we verified whether SMYD2 inhibition increases the susceptibility of HGSOC cells to PARP inhibitors. We analyzed the expression of histone methyltransferase SMYD2 by quantitative real-time polymerase chain reaction and immunohistochemistry using HGSOC clinical tissues (n = 35). We performed functional analyses, including cell proliferation assay, cell cycle analysis, and immunoblotting, after treatment with SMYD2 siRNAs and SMYD2 selective inhibitor LLY-507 in HGSOC cells. We also performed colony-formation assay after combination treatment with LLY-507 and PARP inhibitor olaparib in HGSOC cells. The expression profiles of SMYD2 showed significant overexpression of SMYD2 in HGSOC clinical tissues. The knockdown or inhibition of SMYD2 by siRNAs or LLY-507, respectively, suppressed cell growth by increasing the proportion of apoptotic cells. LLY-507 showed additive effect with olaparib in the colony-formation assay. These findings suggest that LLY-507 can be used alone or in combination with a PARP inhibitor for the treatment of patients with HGSOC.

Activation of Nrf2/Keap1 pathway by oral Dimethylfumarate administration alleviates oxidative stress and age-associated infertility might be delayed in the mouse ovary

BACKGROUND

Age-associated infertility is a problem worldwide, and management of oxidative stress is known to be essential. Nuclear factor-E2-related factor 2 (Nrf2)/Kelch-like ECH-associated protein 1 (Keap1)-antioxidant response element (ARE) signaling pathway works as an essential defense mechanism against oxidative stress, and an oral drug Dimethylfumarate (DMF) is known to activate the pathway.

METHODS

We tested the hypothesis that oral DMF could alleviate oxidative stress in the ovary, resulting in salvation of age-associated infertility in a mouse model of reproductive age, and we examined the effects of DMF administration. 20 mg/kg DMF was administrated to female mice from 32 to 48 weeks, and Nrf2 levels, antioxidant levels, ovarian reserve, DNA damage, and oxidative stress were examined.

RESULTS

DMF administration resulted in elevated mRNA and protein levels of Nrf2, antioxidants, and telomere, and serum levels of Nrf2 and anti-mullerian hormone were also elevated. Results of TUNEL assay and Immunohistochemistry of mice ovarian tissues showed that DNA damage and oxidative stress were decreased by DMF administration, and significantly more oocytes were collected along with preservation of 60% more primordial follicles.

CONCLUSIONS

Our data suggest that DMF administration activates the Nrf2/Keap1 pathway, elevate levels of antioxidants, and decrease DNA damage and oxidative stress, resulting in improved ovarian reserve in the mouse ovary.

Usefulness of cell-free and concentrated ascites reinfusion therapy in the therapeutic management of advanced ovarian cancer patients with massive ascites

BACKGROUND

The management of refractory ascites in advanced ovarian cancer (AOC) is vital for patients with abdominal distention, respiratory distress, and anorexia due to massive ascites with cancer peritonitis. We analyzed the benefits of concentrated ascites reinfusion therapy (CART) in the management of AOC.

METHODS

We reviewed records of AOC patients who underwent CART between January 2011 and March 2017. We retrospectively analyzed patients' backgrounds and physiological changes, including body weight, abdominal girth, urine volume, blood component values, blood pressure, heart rate, and body temperature before and after CART. We investigated the clinicopathological significance of CART by measuring the mean number of ascites tumor cell (ATC) clusters before CART.

RESULTS

A retrospective analysis was performed on 29 cases of AOC with massive ascites involving 47 CART sessions. The patients' mean age was 56.6 ± 12.8 years, and the mean number of sessions was 1.7 ± 1.2. The mean volume of the processed ascites was 2,937 ± 820 mL, which was concentrated to 272 ± 84 mL containing 85.0 ± 33.2 g protein on average. Significant reductions in abdominal girth (- 5.30 ± 0.65 cm; p < 0.0001) and body weight (- 2.97 ± 0.26 kg; p = 0.0011), increased urine volume (+ 824.29 ± 145.21 mL; p < 0.0001), and improved serum albumin levels (+ 0.18 ± 0.34; p < 0.0001) were observed after CART. Analysis of variance revealed significant elevations in body temperature after CART in 11 patients with a small number of ATC clusters.

CONCLUSIONS

CART is useful for the therapeutic management of AOC patients with refractory massive ascites. Elevations of body temperature after CART may be avoided by the investigation of patients' peritoneal cytology before CART.

Kaempferol, a natural dietary flavonoid, suppresses 17β-estradiol-induced survivin expression and causes apoptotic cell death in endometrial cancer

Endometrioid endometrial carcinoma, commonly known as type 1 endometrial cancer, accounts for >80% of endometrial carcinomas and is dependent on estrogen. We recently reported on the prognostic significance of the BIRC5 survivin gene in endometrial cancer. Estradiol induces survivin expression in estrogen receptor-positive, but not in estrogen receptor-negative, cancer cells. Kaempferol, a bioflavonoid, reportedly inhibits estrogen receptor-α (ERα) in hormone receptor-positive breast cancer cells. However, whether kaempferol-mediated inhibition of ERα suppresses survivin and induces cell death in endometrial cancer remains unclarified. The present study evaluated the antitumor effects of kaempferol on endometrial cancer cells. Cell viability assays, flow cytometry analysis, western blotting and annexin V analyses were used to analyze the antitumor effects of kaempferol. The results demonstrated that kaempferol successfully suppressed the viability of two ER-positive endometrial cancer cell lines, with IC₅₀ values of 83 and 65 µM. In addition, kaempferol induced sub-G1 cell accumulation and apoptotic cell death (P<0.01) in a dose-dependent manner. Treatment of cells with estradiol significantly induced co-expression of nuclear ERα and survivin proteins (P<0.001). Further evaluation revealed that kaempferol causes apoptotic cell death largely by suppressing ERα, survivin and Bcl-2 protein. Therefore, the results of the present study suggested that targeting ERα and survivin with kaempferol may be a novel therapeutic option against endometrial carcinoma.

Activation of Nrf2 might reduce oxidative stress in human granulosa cells

Nuclear factor-E2-related factor 2 (Nrf2)/Kelch-like ECH-associated protein 1 (Keap1)-antioxidant response element (ARE) signaling pathway is one of the most important defense mechanisms against oxidative stress (OS). It is well documented that equilibration status of OS plays fundamental roles in human reproductive medicine, and the physiological role of Nrf2 in ovarian granulosa cells (GCs) has not been determined yet. Herein we aimed to study the function of Nrf2 in GCs. Human ovarian tissues were subjected to immunohistochemistry to localize Nrf2 and Keap1 and we detected the expression of Nrf2 and Keap1 in the human GCs. Human luteinized GCs were isolated and cultured, and hydrogen peroxide (H₂O₂) or Dimethylfumarates (DMF), an activator of Nrf2, were added to GCs to analyze the relationship between Nrf2 and antioxidants by quantitative RT-PCR. The mRNA levels of Nrf2, catalase, superoxide dismutase 1 (SOD1), and 8-Oxoguanine DNA glycosylase (OGG1) were elevated by H₂O₂, and DMF treatment showed similar but pronounced effects through activation of Nrf2. To determine the relationship of Nrf2 and the generation of antioxidants, siRNAs were used and quantitative RT-PCR were conducted. Decreased expression of Nrf2 resulted in a decreased level of these antioxidant mRNA. Intracellular levels of ROS were investigated by fluorescence of 8-hydroxy-2'-deoxyguanosine and fluorescent dye, 2',7'-dichlorodihydrofluorescein diacetate after H₂O₂ and/or DMF treatment, and DMF treatment quenched intracellular ROS generation by H₂O₂. These results show that activation of Nrf2 might lead to alleviate OS in human GCs, and this could provide novel insight to conquer the age-related fertility decline that is mainly attributed to the accumulation of aberrant OS.

Oncogenic histone methyltransferase EZH2: A novel prognostic marker with therapeutic potential in endometrial cancer

The histone methyltransferase EZH2, a key epigenetic modifier, is known to be associated with human tumorigenesis. However, the physiological importance of EZH2 and its clinical relevance in endometrial cancer remain unclear. Hence, in the present study, we investigated the expression and function of EZH2 in endometrial cancer. In a quantitative real-time PCR analysis of 11 endometrial cancer cell lines and 52 clinical endometrial cancer specimens, EZH2 was significantly overexpressed in cancer cells and tissues compared to that in corresponding normal control cells and tissues. Kaplan-Meier survival analysis using data of the TCGA RNA-seq database and tissue microarrays (TMAs) indicated that EZH2 overexpression is associated with endometrial cancer prognosis. In addition, knockdown of EZH2 using specific siRNAs resulted in growth suppression and apoptosis induction of endometrial cancer cells, accompanied by attenuation of H3K27 trimethylation. Consistent with these results, treatment with GSK126, a specific EZH2 inhibitor, suppressed endometrial cancer cell growth and decreased the number of cancer cell colonies. Furthermore, GSK126 showed additive effects with doxorubicin or cisplatin, which are conventional drugs for treatment of endometrial cancer. Further studies should explore the therapeutic potential of inhibiting EZH2 in patients with endometrial cancer.

Abstract 1430: The spliceosome U2 snRNP factors promote genome stability through distinct mechanisms; transcription of repair factors and R-loop processing

(Objective)Recent whole-exome sequencing studies of malignancies have detected recurrent somatic mutations in U2 snRNP components of the spliceosome. These factors have also been listed as novel players of DNA damage response in several genome wide screens and proteome analysis for DDR genes. Although accumulating evidences have implied that the spliceosome plays an important role in genome stability and is an emerging hallmark of carcinogenic pathways, its precise role in genome stability still remains ambiguous. The aim of this study is to clarify the functions of U2 snRNP splicing factors, especially SNRPA1 (Small Nuclear Ribonucleoprotein Polypeptide A1) in DDR pathway.

(Methods)SNAPA1 and other U2 snRNP splicing factors were identified as HR repair genes by genome-wide screens based on homologous recombination and RAD51 immunofoci formation. Each splicing factor was depleted by siRNA knockdown in USOS cells. The functions of SNRPA1 in DNA repair were analyzed by HR assay (DR-GFP assay), immunofluorescence, real-time laser micro-irradiation and comet assay (single cell gel electrophoresis).

(Results)HR assay showed strong HR deficiencies in splicing factor's depleted cells. In these cells, accumulation of BRCA1 and Rad51, major HR factors, to DNA damage sites were severely impaired. Especially, live cell imaging showed recruitment of SNRPA1 to laser induced DNA damage sites and unveiled its direct involvement to DNA damage repair. Comet assay also showed that depletion of SNRPA1 markedly caused DNA damage with the tail of broken DNA fragments. This DNA damage was R-loop (DNA-RNA hybrid) mediated DNA damage and rescued by overexpression of RNAseH1.

(Conclusion) Here we unveiled two distinct pathways how spliceosome U2 snRNP factors contribute to genome stability. The main function is indirect, through transcription, to maintain the protein levels of essential repair factors and contribute to homologous recombination repair. Our data suggest that depletion of splicing factors can be one mechanism for HR deficiency (i.e. BRCAness). In addition real-time laser microirradiation analysis identified the rapid recruitment of SNRPA1 to DNA damage sites. Intensive functional analysis of SNRPA1 unveiled the other, more immediate and direct effect to process R-loop structure, deleterious transcriptional by-products for the genome, at sites of on-going transcription.

Citation Format: Michihiro Tanikawa. The spliceosome U2 snRNP factors promote genome stability through distinct mechanisms; transcription of repair factors and R-loop processing [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1430. doi:10.1158/1538-7445.AM2017-1430