Potential for Mitochondrial DNA Sequencing in the Differential Diagnosis of Gynaecological Malignancies

The contribution of mitochondrial DNA alterations to aging, cancer, and neurodegeneration

Mitochondrial DNA (mtDNA) is as a double-stranded molecule existing in hundreds to thousands copies in cells depending on cell metabolism and exposure to endogenous and/or environmental stressors. The coordination of mtDNA replication and transcription regulates the pace of mitochondrial biogenesis to guarantee the minimum number of organelles per cell. mtDNA inheritance follows a maternal lineage, although bi-parental inheritance has been reported in some species and in the case of mitochondrial diseases in humans. mtDNA mutations (e.g., point mutations, deletions, copy number variations) have been identified in the setting of several human diseases. For instance, sporadic and inherited rare disorders involving the nervous system as well higher risk of developing cancer and neurodegenerative conditions, including Parkinson's and Alzheimer's disease, have been associated with polymorphic mtDNA variants. An accrual of mtDNA mutations has also been identified in several tissues and organs, including heart and muscle, of old experimental animals and humans, which may contribute to the development of aging phenotypes. The role played by mtDNA homeostasis and mtDNA quality control pathways in human health is actively investigated for the possibility of developing targeted therapeutics for a wide range of conditions.

Meta-analysis of the diagnostic value of 18F-FDG PET/CT in the recurrence of epithelial ovarian cancer

BACKGROUND

Ovarian cancer is the leading cause of cancer-related death among gynecologic malignancies. With much evidence suggesting that 18F-FDG PET/CT may be an excellent imaging test for the diagnosis of epithelial ovarian cancer recurrence, we conducted a systematic review and meta-analysis to summarize relevant studies and evaluate the accuracy and application value of 18F-FDG PET/CT in the diagnosis of recurrence of epithelial ovarian cancer.

MATERIALS AND METHODS

Clinical trials of 18F-FDG PET/CT for the diagnosis of recurrence of epithelial ovarian cancer were systematically searched in PubMed, Embase, Cochrane Library, Web of Science and OVID database. The relevant literature was searched until May 22, 2022. Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) was used to evaluate the quality of the included original studies, and the meta-analysis was performed using a bivariate mixed-effects model and completed in Stata 15.0.

RESULTS

A total of 17 studies on 18F-FDG PET/CT for the diagnosis of epithelial ovarian cancer recurrence were included in this systematic review, involving 639 patients with epithelial ovarian cancer. Meta-analysis showed that the sensitivity, specificity and area under the curve of 18F-FDG PET/CT for the diagnosis of epithelial ovarian cancer recurrence were 0.88 (95% CI: 0.79 - 0.93), 0.89 (95% CI: 0.72 - 0.96) and 0.94 (95% CI: 0.91- 0.96), respectively. Subgroup analysis showed higher diagnostic efficacy in prospective studies than in retrospective studies, and no significant publication bias was observed in Deeks' funnel plot, with sensitivity analysis revealing the stability of results. Meta regression shows that the heterogeneity of this study comes from study type.

CONCLUSION

18F-FDG PET/CT has good diagnostic value in the recurrence of epithelial ovarian cancer.

Meigs' syndrome and adult-type granulosa cell tumor

OBJECTIVE

Adult-type granulosa cell tumors (GCT) are sex cord-stromal tumors and often accompanied with abdominal distention and hyperestrogenism-related symptoms. Adult-type GCT-presenting ascites and pleural effusion is extremely rare.

CASE REPORT

A 56-year-old perimenopausal woman presented with abdominal distention and abnormal vaginal spotting. Ultrasound and abdominal computed tomography showed a complex cystic mass in the left ovary accompanied with bilateral pleural effusion and ascites. The patient underwent total abdominal hysterectomy, bilateral salpingo-oophorectomy, left pelvic lymph node dissection, omentectomy and appendectomy. Final histopathological diagnosis was adult-type GCT. The patient had postoperative hormone and anti-angiogenesis agent therapy with free of disease.

CONCLUSION

Ovarian cystic complex mass accompanied with ascites and pleural effusion often results from malignant ovarian tumors or benign ovarian fibroma. Based on the aforementioned report, the rare types of ovarian tumors, such as adult-type granulosa cell tumor of the ovary should be taken into consideration.

Mitochondrial DNA variation and cancer

Variation in the mitochondrial DNA (mtDNA) sequence is common in certain tumours. Two classes of cancer mtDNA variants can be identified: de novo mutations that act as 'inducers' of carcinogenesis and functional variants that act as 'adaptors', permitting cancer cells to thrive in different environments. These mtDNA variants have three origins: inherited variants, which run in families, somatic mutations arising within each cell or individual, and variants that are also associated with ancient mtDNA lineages (haplogroups) and are thought to permit adaptation to changing tissue or geographic environments. In addition to mtDNA sequence variation, mtDNA copy number and perhaps transfer of mtDNA sequences into the nucleus can contribute to certain cancers. Strong functional relevance of mtDNA variation has been demonstrated in oncocytoma and prostate cancer, while mtDNA variation has been reported in multiple other cancer types. Alterations in nuclear DNA-encoded mitochondrial genes have confirmed the importance of mitochondrial metabolism in cancer, affecting mitochondrial reactive oxygen species production, redox state and mitochondrial intermediates that act as substrates for chromatin-modifying enzymes. Hence, subtle changes in the mitochondrial genotype can have profound effects on the nucleus, as well as carcinogenesis and cancer progression.

Mitochondrial DNA analysis efficiently contributes to the identification of metastatic contralateral breast cancers

Purpose

In daily practice, a contralateral breast cancer (CBC) is usually considered as a new independent tumor despite the indications of several studies showing that the second neoplasia may be a metastatic spread of the primary tumor. Recognition of clonal masses in the context of multiple synchronous or metachronous tumors is crucial for correct prognosis, therapeutic choice, and patient management. Mitochondrial DNA (mtDNA) sequencing shows high informative potential in the diagnosis of synchronous neoplasms, based on the fact that somatic mtDNA mutations are non-recurrent events, whereas tumors sharing them have a common origin. We here applied this technique to reveal clonality of the CBC with respect to the first tumor.

Methods

We analyzed 30 sample pairs of primary breast cancers and synchronous or metachronous CBCs with detailed clinical information available and compared standard clinico-pathological criteria with mtDNA sequencing to reveal the metastatic nature of CBCs.

Results

MtDNA analysis was informative in 23% of the cases, for which it confirmed a clonal origin of the second tumor. In addition, it allowed to solve two ambiguous cases where histopathological criteria had failed to be conclusive and to suggest a clonal origin for two additional cases that had been classified as independent by pathologists.

Conclusion

Overall, the mtDNA-based classification showed a more accurate predictive power than standard histopathology in identifying cases of metastatic rather than bilateral breast cancers in our cohort, suggesting that mtDNA sequencing may be a more precise and easy-to-use method to be introduced in daily routine to support and improve histopathological diagnoses.

Pathogenic Heteroplasmic Somatic Mitochondrial DNA Mutation Confers Platinum-Resistance and Recurrence of High-Grade Serous Ovarian Cancer

Purpose

Platinum resistance is a primary barrier to improving the survival rate of ovarian cancer. The relationship between mtDNA somatic mutations and response to platinum-based chemotherapy in ovarian cancer has not been well clarified.

Patients and Methods

Here, we employed the next-generation sequencing (NGS) platform to identify mtDNA mutations of the unrelated high-grade serous ovarian cancer (HGSOC) patients.

Results

We identified 569 germline variants and 28 mtDNA somatic mutations, and found the platinum-sensitive relapsed HGSOC patients had more synonymous mutations while the platinum-resistant relapsed HGSOC patients had more missense mutations in the mtDNA somatic mutations. Meanwhile, we found that the HGSOC patients who harbored heteroplasmic pathogenic mtDNA somatic mutations had significantly higher prevalence of both platinum-resistance and relapse than those without (80.0% versus 16.7%, p=0.035). Additionally, we observed that the tumor tissues had significantly higher lactate-to-pyruvate (L/P) ratio than the paired nontumor tissues (p<0.001), and L/P ratio of tumors with any heteroplasmic pathogenic mtDNA mutations was significantly higher than that of the tumors free of pathogenic mtDNA mutations (p=0.025).

Conclusion

Our findings indicate that these heteroplasmic pathogenic mtDNA somatic mutations may cause decreased respiratory chain activity and lead to the metabolism remodeling that seem to be beneficial for progression of both platinum-based chemotherapy resistance and relapse.

An Analysis of Clinical, Surgical, Pathological and Molecular Characteristics of Endometrial Cancer According to Mismatch Repair Status. A Multidisciplinary Approach

Since 2016, our hospital has applied tumor testing with immunohistochemistry (IHC) in endometrial cancer in order to detect mutations of mismatch repair genes (MMR). All cases with MMR deficiency proteins expression are sent for genetic testing, except those with MLH1 protein deficiency, in which case genetic testing is performed if negative for promoter hypermethylation. The primary aim of this study was to investigate the ability of our algorithm to identify Lynch syndrome (LS). The Secondary aims were to investigate the relationship between MMR status and clinicopathological features and prognosis of primary endometrial cancer (EC). From January 2016 to December 2018, 239 patients with EC were retrospectively analyzed and subdivided according to MMR status. Patients were divided in three groups: MMR proficient, LS and Lynch-like cancer (LLC). LS was characterized by a lower age and BMI, more use of contraceptive and less use of hormonal replacement therapy, nulliparity and a trend versus a better prognosis. LLC appeared more related to MMR proficient than LS and exhibited a more aggressive behavior. Our multidisciplinary approach permitted a correct diagnosis of germline mutation in patients with newly diagnosis EC and it confirmed clinicopathologic and prognostic characteristics of LS.

Construction of a 14-lncRNA risk score system predicting survival of children with acute myelocytic leukemia

Acute myelocytic leukemia (AML) is a frequent type of acute leukemia. The present study was performed to build a risk score system for the prognostic prediction of AML. AML RNA-sequencing data from samples from 111 children were downloaded from The Cancer Genome Atlas database. Using the DEseq and edgeR packages, the differentially expressed long non-coding RNAs (DE-lncRNAs) between bad and good prognosis groups were identified. A survival package was used to screen prognosis-associated lncRNAs and clinical factors. The optimal lncRNA combination was selected using the penalized package, and the risk-score system was built and evaluated. After the lncRNA-mRNA expression correlation network was constructed, the potential pathways involving the key lncRNAs were enriched using Gene Set Enrichment Analysis. Among the 61 DE-lncRNAs, 48 lncRNAs were significantly associated with prognosis. Relapse was an independent prognostic factor. The optimal 14-lncRNA risk score system was constructed. After 730 differentially expressed mRNAs were identified between the good and bad prognosis groups divided using a prognostic index, the lncRNA-mRNA expression correlation network was constructed. Enrichment analysis showed that semaphorin-3C [SEMA3C; regulated by probable leucine-tRNA ligase, mitochondrial (LARS2-AS1)] and secreted frizzled-related protein 5 [SFRP5; mediated by WASH complex subunit 5 (WASHC5)-antisense RNA 1 (AS1)] were involved in axon guidance and the Wnt signaling pathway, respectively. A 14-lncRNA (including paired box protein Pax8-AS1 and MYB AS1) risk-score system might be effective in predicting the prognosis of AML. Axon guidance (involving SEMA3C and LARS2-AS1) and the Wnt signaling pathway (involving SFRP5 and WASHC5-AS1) might be two important pathways affecting the prognosis of AML.

The Interplay of Tumor Stroma and Translational Factors in Endometrial Cancer

Endometrial cancer (EC) is a common gynecologic malignancy which continues to have a poor prognosis in advanced stages due to current therapeutic limitations. A significant mechanism of chemoresistance in EC has been shown to also be the enhancement of epithelial to mesenchymal transition (EMT) and the subsequent obtainment of stem cell-like characteristics of EC. Current evidence on EMT in EC however fails to explain the relationship leading to an EMT signaling enhancement. Our review therefore focuses on understanding eukaryotic translation initiation factors (eIFs) as key regulators of the translational process in enhancing EMT and subsequently impacting higher chemoresistance of EC. We identified pathways connected to the development of a microenvironment for EMT, inducers of the process specifically related to estrogen receptors as well as their interplay with eIFs. In the future, investigation elucidating the translational biology of EC in EMT may therefore focus on the signaling between protein kinase RNA-like ER kinase (PERK) and eIF2alpha as well as eIF3B.

Discovery of a Ruthenium Complex for the Theranosis of Glioma through Targeting the Mitochondrial DNA with Bioinformatic Methods

Glioma is the most aggressive and lethal brain tumor in humans. Mutations of mitochondrial DNA (mtDNA) are commonly found in tumor cells and are closely associated with tumorigenesis and progress. However, glioma-specific inhibitors that reflect the unique feature of tumor cells are rare. Here we uncover RC-7, a ruthenium complex with strong red fluorescence, could bind with glioma mtDNA and then inhibited the growth of human glioma cells but not that of neuronal cells, liver, or endothelial cells. RC-7 significantly reduced energy production and increased the oxidative stress in the glioma cells. Administration of RC-7 into mice not only could be observed in the glioma mass of brain by fluorescence imaging, but also obviously prevented the growth of xenograft glioma and prolonged mouse survival days. The findings suggested the theranostic application of a novel type of complex through targeting the tumor mtDNA.

The prognosis of stage IA synchronous endometrial endometrioid and ovarian carcinomas

Introduction

Little is known about the prevalence and prognosis of synchronous endometrial and ovarian carcinomas. This report explores the survival outcomes of synchronous stage IA endometrioid endometrial and stage IA ovarian carcinomas in a retrospective cohort study.

Methods

All cases of pathological confirmed synchronous stage IA endometrial endometrioid and ovarian carcinomas from June 1, 2010, to June 1, 2017, in a teaching hospital were reviewed. Patients were followed up to February 1, 2019. Survival outcomes were compared between patients with and without synchronous carcinomas.

Results

In total, 841 cases with confirmed FIGO stage IA endometrioid endometrial carcinomas were included in the study; 33 patients (3.9%) had synchronous stage IA ovarian carcinomas, including 27 (81.8%) and 6 (18.2%) cases of endometrioid and mixed endometrioid/clear cell subtypes, respectively. After a median follow-up time of 56.8 months, 829 patients (97.9%) had definitive survival outcomes. Synchronous ovarian carcinomas had no impact on disease-free, overall or cancer-specific overall survival in univariate and multivariate analyses.

Conclusion

In these patients with stage IA endometrioid endometrial carcinoma, the genuine incidence of synchronous stage IA ovarian carcinoma was very low, and synchronous carcinoma had no significant effects on survival outcomes.

Electronic supplementary material

The online version of this article (10.1007/s00404-019-05288-5) contains supplementary material, which is available to authorized users.

Potential Prognostic Role of 18F-FDG PET/CT in Invasive Epithelial Ovarian Cancer Relapse. A Preliminary Study

Epithelial ovarian cancer (EOC) is the most lethal gynecological malignancy, with relapse occurring in about 70% of advanced cases with poor prognosis. Fluorine-18-2-fluoro-2-deoxy-d-glucose PET/CT (¹⁸F-FDGPET/CT) is the most specific radiological imaging used to assess recurrence. Some intensity-based and volume-based PET parameters, maximum standardized uptake values (SUV_max), metabolic tumor volume (MTV) and total lesion glycolysis (TLG), are indicated to have a correlation with treatment response. The aim of our study is to correlate these parameters with post relapse survival (PRS) and overall survival (OS) in Epithelial Ovarian Cancer (EOC) relapse. The study included 50 patients affected by EOC relapse who underwent ¹⁸F-FDGPET/CT before surgery. All imaging was reviewed and SUV_max, MTV and TLG were calculated and correlated to PRS and OS. PRS and OS were obtained from the first relapse and from the first diagnosis to the last follow up or death, respectively. SUV_max, MTV and TLG were tested in a univariate logistic regression analysis, only SUV_max demonstrated to be significantly associated to PRS and OS (p = 0.005 and p = 0.024 respectively). Multivariate analysis confirmed the results. We found a cut-off of SUV_max of 13 that defined worse or better survival (p = 0.003). In the first relapse of EOC, SUV_max is correlated to PRS and OS, and when SUV_max is greater than 13, it is an unfavorable prognostic factor.