Metabolic risk factors and mechanisms of disease in epithelial ovarian cancer: A review

Hepatitis B virus infection and the risk of gynecologic cancers: a systematic review and meta-analysis

OBJECTIVES

The relationship between hepatitis B virus (HBV) infection and gynecologic cancers is controversial. We aimed to evaluate the risk of gynecologic cancers associated with HBV infection using a meta-analysis.

METHODS

Two independent reviewers identified publications in the PubMed, Embase and Cochrane Library databases that reported an association between HBV and the risk of gynecologic malignancy from inception to December 31, 2022. The Newcastle-Ottawa Scale (NOS) was used to evaluate the quality of the included articles. Pooled odds ratios (ORs) and 95% corresponding confidence intervals (CIs) were calculated using a fixed effects model or random effects model.

RESULTS

We collected data from 7 studies that met the inclusion criteria, including 2 cohort studies and 5 case-control studies. HBV was significantly associated with the risk of cervical cancer in the general population (OR 1.22, 95% CI 1.09-1.38, P = 0.001), although the same trend was not found in endometrial cancer (OR 1.30, 95% CI 0.95-1.77, P = 0.105) and ovarian cancer (OR 1.03, 95% CI 0.79-1.35, P = 0.813). Subgroup analysis showed that HBV infection was positively associated with the risk of cervical cancer (OR 1.27, 95% CI 1.13-1.44, P = 0.000) in case-control studies. Asian women infected with HBV have a significantly increased risk of cervical cancer (OR 1.24, 95% CI 1.10-1.40, P = 0.001) and endometrial cancer (OR 1.46, 95% CI 1.07-1.99, P = 0.018). Hospital-based studies were found to be associated with an increased risk of cervical cancer (OR 1.30, 95% CI 1.14-1.47, P = 0.000) and endometrial cancer (OR 1.61, 95% CI 1.04-2.49, P = 0.032). The results of Begg's and Egger's tests showed no publication bias.

CONCLUSIONS

This meta-analysis shows a positive association between HBV infection and cervical cancer. HBV is positively correlated with the risk of cervical cancer and endometrial cancer in Asian women and hospital-based populations. More multicenter prospective studies are required to confirm the findings.

Regression of ovarian cancer xenografts by depleting or inhibiting RLIP

Ovarian cancer (OC) is the most prevalent and deadly cancer of the female reproductive system. Women will continue to be impacted by OC-related morbidity and mortality. Despite the fact that chemotherapy with cisplatin is the main component as the first-line anticancer treatment for OC, chemoresistance and unfavorable side effects are important obstacles to effective treatment. Targets for effective cancer therapy are required for cancer cells but not for non-malignant cells because they are expressed differently in cancer cells compared to normal cells. Targets for cancer therapy should preferably be components that already exist in biochemical and signalling frameworks and that significantly contribute to the development of cancer or regulate the response to therapy. RLIP is an important mercapturic acid pathway transporter that is crucial for survival and therapy resistance in cancers, therefore, we examined the role of RLIP in regulating essential signalling proteins involved in relaying the inputs from upstream survival pathways and mechanisms contributing to chemo-radiotherapy resistance in OC. The findings of our research offer insight into a novel anticancer effect of RLIP depletion/inhibition on OC and might open up new therapeutic avenues for OC therapy.

Etiopathogenesis of ovarian cancer. An inflamm-aging entity?

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Ovarian cancer (OvCa) is a multifactorial disease.

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Several factors are involved in age-related increases in carcinogenesis.

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Exposure to inflammatory mediators contributes to increased cell division and genetic and epigenetic changes.

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We discuss the current carcinogenic hypotheses, sites of origin, and etiological factors of OvCa.

Ovarian cancer is one of the most common gynecologic cancers and has the highest mortality rate. The risk/protective factors of ovarian cancer suggest that its etiology is multifactorial. Several factors are involved in age-related increases in carcinogenesis, including the accumulation of senescent cells, inflammaging (a chronic inflammatory state that persists in the elderly), and immunosenescence (aging of the immune system) changes associated with poor immune surveillance. At sites of inflammation, exposure to high levels of inflammatory mediators, such as reactive oxygen species, cytokines, prostaglandins, and growth factors, contributes to increased cell division and genetic and epigenetic changes. These exposure-induced changes promote excessive cell proliferation, increased survival, malignant transformation, and cancer development. Furthermore, the proinflammatory tumor microenvironment contributes to ovarian cancer metastasis and chemoresistance.

This narrative review of the literature was carried out to delineate the possible role of inflammaging in the etiopathogenesis of ovarian cancer development. We discuss the current carcinogenic hypotheses, sites of origin, and etiological factors of ovarian cancer. Treatment of inflammation may represent an attractive strategy for both the prevention and therapy of ovarian cancer.

Metabolic risk factors of ovarian cancer: a review

Ovarian cancer continues to be the leading cause of death from gynecological cancers. Despite inconsistent results, patients with metabolic abnormalities, including obesity and diabetes mellitus (DM), have poorer outcomes, showing a correlation with ovarian cancer incidence and ovarian cancer survival. Since ovarian cancer is the most common cancer in women, and considering the increasing prevalence of obesity and DM, this paper reviews the literature regarding the relationship between the aforementioned metabolic derangements and ovarian cancer, with a focus on ovarian cancer incidence, mortality, and likely mechanisms behind them. Several systematic reviews and meta-analyses have shown that obesity is associated with a higher incidence and poorer survival in ovarian cancer. Although more studies are required to investigate the etiological relation of DM and ovarian cancer, sufficient biological evidence indicates poorer outcomes and shorter survival in DM women with ovarian cancer. A variety of pathologic factors may contribute to ovarian cancer risk, development, and survival, including altered adipokine expression, increased levels of circulating growth factors, altered levels of sex hormones, insulin resistance, hyperinsulinemia, and chronic inflammation. Thus, obesity and DM, as changeable risk factors, can be targeted for intervention to prevent ovarian cancer and improve its outcomes.

Identification of key genes associated with polycystic ovary syndrome (PCOS) and ovarian cancer using an integrated bioinformatics analysis

BACKGROUND

Accumulating evidence suggests a strong association between polycystic ovary syndrome (PCOS) and ovarian cancer (OC), but the potential molecular mechanism remains unclear. In this study, we identified previously unrecognized genes that are significantly correlated with PCOS and OC via bioinformatics.

MATERIALS AND METHODS

Multiple bioinformatic analyses, such as differential expression analysis, univariate Cox analysis, functional and pathway enrichment analysis, protein-protein interaction (PPI) network construction, survival analysis, and immune infiltration analysis, were utilized. We further evaluated the effect of OGN on FSHR expression via immunofluorescence.

RESULTS

TCGA-OC, GSE140082 (for OC) and GSE34526 (for PCOS) datasets were downloaded. Twelve genes, including RNF144B, LPAR3, CRISPLD2, JCHAIN, OR7E14P, IL27RA, PTPRD, STAT1, NR4A1, OGN, GALNT6 and CXCL11, were identified as signature genes. Drug sensitivity analysis showed that OGN might represent a hub gene in the progression of PCOS and OC. Experimental analysis found that OGN could increase FSHR expression, indicating that OGN could regulate the hormonal response in PCOS and OC. Furthermore, correlation analysis indicated that OGN function might be closely related to m6A and ferroptosis.

CONCLUSIONS

Our study identified a 12-gene signature that might be involved in the prognostic significance of OC. Furthermore, the hub gene OGN represent a significant gene involved in OC and PCOS progression by regulating the hormonal response.

The miR-33a-5p/CROT axis mediates ovarian cancer cell behaviors and chemoresistance via the regulation of the TGF-β signal pathway

Due to the lack of symptoms and detection biomarkers at the early stage, most patients with ovarian cancer (OC) are diagnosed at an advanced stage and often face chemoresistance and relapse. Hence, defining detection biomarkers and mechanisms of chemoresistance is imperative. A previous report of a cDNA microarray analysis shows a potential association of carnitine O-octanoyltransferase (CROT) with taxane resistance but the biological function of CROT in OC remains unknown. The current study explored the function and regulatory mechanism of CROT on cellular behavior and paclitaxel (PTX)-resistance in OC. We found that CROT was downregulated in OC tissues and PTX-resistant cells. Furthermore, CROT expression was negatively correlated with the prognosis of OC patients. Overexpression of CROT inhibited the OC cell proliferation, migration, invasion, and colony formation, arrested the cell cycle at the G2/M phase, and promoted cell apoptosis. In addition, miR-33a-5p bound directly to the 3'UTR of CROT to negatively regulate the expression of CROT and promoted OC cell growth. Finally, overexpression of CROT decreased the phosphorylation of Smad2, whereas knockdown of CROT increased the nuclear translocation of Smad2 and Smad4, two transducer proteins of TGF-β signaling, indicating that CROT is a tumor suppressor which mediates OC cell behaviors through the TGF-β signaling pathway. Thus, targeting the miR-33a-5p/CROT axis may have clinical potential for the treatment of patients with OC.

Potential Role of Diabetes Mellitus-Associated T Cell Senescence in Epithelial Ovarian Cancer Omental Metastasis

Epithelial ovarian cancer (EOC) is one of the most common causes of cancer-related deaths among women and is associated with age and age-related diseases. With increasing evidence of risks associated with metabolic inflammatory conditions, such as obesity and type 2 diabetes mellitus (T2DM), it is important to understand the complex pathophysiological mechanisms underlying cancer progression and metastasis. Age-related conditions can lead to both genotypic and phenotypic immune function alterations, such as induction of senescence, which can contribute to disease progression. Immune senescence is a common phenomenon in the ageing population, which is now known to play a role in multiple diseases, often detrimentally. EOC progression and metastasis, with the highest rates in the 75-79 age group in women, have been shown to be influenced by immune cells within the "milky spots" or immune clusters of the omentum. As T2DM has been reported to cause T cell senescence in both prediabetic and diabetic patients, there is a possibility that poor prognosis in EOC patients with T2DM is partly due to the accumulation of senescent T cells in the omentum. In this review, we explore this hypothesis with recent findings, potential therapeutic approaches, and future directions.

A multidisciplinary approach remains the best strategy to improve and strengthen the management of ovarian cancer (Review)

Ovarian cancer represents one of the most aggressive female tumors worldwide. Over the decades, the therapeutic options for the treatment of ovarian cancer have been improved significantly through the advancement of surgical techniques as well as the availability of novel effective drugs able to extend the life expectancy of patients. However, due to its clinical, biological and molecular complexity, ovarian cancer is still considered one of the most difficult tumors to manage. In this context, several studies have highlighted how a multidisciplinary approach to this pathology improves the prognosis and survival of patients with ovarian cancer. On these bases, the aim of the present review is to present recent advantages in the diagnosis, staging and treatment of ovarian cancer highlighting the benefits of a patient‑centered care approach and on the importance of a multidisciplinary team for the management of ovarian cancer.

Comorbidities and inflammation associated with ovarian cancer and its influence on SARS-CoV-2 infection

Coronavirus disease 2019 (COVID-19) caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) worldwide is a major public health concern. Cancer patients are considered a vulnerable population to SARS-CoV-2 infection and may develop several COVID-19 symptoms. The heightened immunocompromised state, prolonged chronic pro-inflammatory milieu coupled with comorbid conditions are shared in both disease conditions and may influence patient outcome. Although ovarian cancer (OC) and COVID-19 are diseases of entirely different primary organs, both diseases share similar molecular and cellular characteristics in their microenvironment suggesting a potential cooperativity leading to poor outcome. In COVID-19 related cases, hospitalizations and deaths worldwide are lower in women than in males; however, comorbidities associated with OC may increase the COVID-19 risk in women. The women at the age of 50-60 years are at greater risk of developing OC as well as SARS-CoV-2 infection. Increased levels of gonadotropin and androgen, dysregulated renin-angiotensin-aldosterone system (RAAS), hyper-coagulation and chronic inflammation are common conditions observed among OC and severe cases of COVID-19. The upregulation of common inflammatory cytokines and chemokines such as tumor necrosis factor α (TNF-α), interleukin (IL)-1β, IL-2, IL-6, IL-10, interferon-γ-inducible protein 10 (IP-10), granulocyte colony-stimulating factor (G-CSF), monocyte chemoattractant protein-1 (MCP-1), macrophage colony-stimulating factor (M-CSF), among others in the sera of COVID-19 and OC subjects suggests potentially similar mechanism(s) involved in the hyper-inflammatory condition observed in both disease states. Thus, it is conceivable that the pathogenesis of OC may significantly contribute to the potential infection by SARS-CoV-2. Our understanding of the influence and mechanisms of SARS-CoV-2 infection on OC is at an early stage and in this article, we review the underlying pathogenesis presented by various comorbidities of OC and correlate their influence on SARS-CoV-2 infection.

Integrated bioinformatics analysis for the screening of hub genes and therapeutic drugs in ovarian cancer

Background

Ovarian cancer (OC) ranks fifth as a cause of gynecological cancer-associated death globally. Until now, the molecular mechanisms underlying the tumorigenesis and prognosis of OC have not been fully understood. This study aims to identify hub genes and therapeutic drugs involved in OC.

Methods

Four gene expression profiles (GSE54388, GSE69428, GSE36668, and GSE40595) were downloaded from the Gene Expression Omnibus (GEO), and the differentially expressed genes (DEGs) in OC tissues and normal tissues with an adjusted P-value < 0.05 and a |log fold change (FC)| > 1.0 were first identified by GEO2R and FunRich software. Next, Gene Ontology (GO) and Kyoto Encyclopaedia of Genes and Genomes (KEGG) analyses were performed for functional enrichment analysis of these DEGs. Then, the hub genes were identified by the cytoHubba plugin and the other bioinformatics approaches including protein-protein interaction (PPI) network analysis, module analysis, survival analysis, and miRNA-hub gene network construction was also performed. Finally, the GEPIA2 and DGIdb databases were utilized to verify the expression levels of hub genes and to select the candidate drugs for OC, respectively.

Results

A total of 171 DEGs were identified, including 114 upregulated and 57 downregulated DEGs. The results of the GO analysis indicated that the upregulated DEGs were mainly involved in cell division, nucleus, and protein binding, whereas the biological functions showing enrichment in the downregulated DEGs were mainly negative regulation of transcription from RNA polymerase II promoter, protein complex and apicolateral plasma membrane, and glycosaminoglycan binding. As for the KEGG-pathway, the upregulated DEGs were mainly associated with metabolic pathways, biosynthesis of antibiotics, biosynthesis of amino acids, cell cycle, and HTLV-I infection. Additionally, 10 hub genes (KIF4A, CDC20, CCNB2, TOP2A, RRM2, TYMS, KIF11, BIRC5, BUB1B, and FOXM1) were identified and survival analysis of these hub genes showed that OC patients with the high-expression of CCNB2, TYMS, KIF11, KIF4A, BIRC5, BUB1B, FOXM1, and CDC20 were statistically more likely to have poorer progression free survival. Meanwhile, the expression levels of the hub genes based on GEPIA2 were in accordance with those based on GEO. Finally, DGIdb database was used to identify 62 small molecules as the potentially targeted drugs for OC treatment.

Conclusions

In summary, the data may produce new insights regarding OC pathogenesis and treatment. Hub genes and candidate drugs may improve individualized diagnosis and therapy for OC in future.

Ovarian cancer risk factors by tumor aggressiveness: An analysis from the Ovarian Cancer Cohort Consortium

Ovarian cancer risk factors differ by histotype; however, within subtype, there is substantial variability in outcomes. We hypothesized that risk factor profiles may influence tumor aggressiveness, defined by time between diagnosis and death, independent of histology. Among 1.3 million women from 21 prospective cohorts, 4,584 invasive epithelial ovarian cancers were identified and classified as highly aggressive (death in <1 year, n = 864), very aggressive (death in 1 to < 3 years, n = 1,390), moderately aggressive (death in 3 to < 5 years, n = 639), and less aggressive (lived 5+ years, n = 1,691). Using competing risks Cox proportional hazards regression, we assessed heterogeneity of associations by tumor aggressiveness for all cases and among serous and endometrioid/clear cell tumors. Associations between parity (p_het = 0.01), family history of ovarian cancer (p_het = 0.02), body mass index (BMI; p_het ≤ 0.04) and smoking (p_het < 0.01) and ovarian cancer risk differed by aggressiveness. A first/single pregnancy, relative to nulliparity, was inversely associated with highly aggressive disease (HR: 0.72; 95% CI [0.58-0.88]), no association was observed for subsequent pregnancies (per pregnancy, 0.97 [0.92-1.02]). In contrast, first and subsequent pregnancies were similarly associated with less aggressive disease (0.87 for both). Family history of ovarian cancer was only associated with risk of less aggressive disease (1.94 [1.47-2.55]). High BMI (≥35 vs. 20 to < 25 kg/m² , 1.93 [1.46-2.56] and current smoking (vs. never, 1.30 [1.07-1.57]) were associated with increased risk of highly aggressive disease. Results were similar within histotypes. Ovarian cancer risk factors may be directly associated with subtypes defined by tumor aggressiveness, rather than through differential effects on histology. Studies to assess biological pathways are warranted.

Ovarian cancer risk factors by tumor aggressiveness: An analysis from the Ovarian Cancer Cohort Consortium

Ovarian cancer risk factors differ by histotype; however, within subtype, there is substantial variability in outcomes. We hypothesized that risk factor profiles may influence tumor aggressiveness, defined by time between diagnosis and death, independent of histology. Among 1.3 million women from 21 prospective cohorts, 4,584 invasive epithelial ovarian cancers were identified and classified as highly aggressive (death in <1 year, n = 864), very aggressive (death in 1 to < 3 years, n = 1,390), moderately aggressive (death in 3 to < 5 years, n = 639), and less aggressive (lived 5+ years, n = 1,691). Using competing risks Cox proportional hazards regression, we assessed heterogeneity of associations by tumor aggressiveness for all cases and among serous and endometrioid/clear cell tumors. Associations between parity (phet = 0.01), family history of ovarian cancer (phet = 0.02), body mass index (BMI; phet ≤ 0.04) and smoking (phet < 0.01) and ovarian cancer risk differed by aggressiveness. A first/single pregnancy, relative to nulliparity, was inversely associated with highly aggressive disease (HR: 0.72; 95% CI [0.58-0.88]), no association was observed for subsequent pregnancies (per pregnancy, 0.97 [0.92-1.02]). In contrast, first and subsequent pregnancies were similarly associated with less aggressive disease (0.87 for both). Family history of ovarian cancer was only associated with risk of less aggressive disease (1.94 [1.47-2.55]). High BMI (≥35 vs. 20 to < 25 kg/m2 , 1.93 [1.46-2.56] and current smoking (vs. never, 1.30 [1.07-1.57]) were associated with increased risk of highly aggressive disease. Results were similar within histotypes. Ovarian cancer risk factors may be directly associated with subtypes defined by tumor aggressiveness, rather than through differential effects on histology. Studies to assess biological pathways are warranted.

Ovarian cancer risk factors by tumor aggressiveness: An analysis from the Ovarian Cancer Cohort Consortium

Ovarian cancer risk factors differ by histotype; however, within subtype, there is substantial variability in outcomes. We hypothesized that risk factor profiles may influence tumor aggressiveness, defined by time between diagnosis and death, independent of histology. Among 1.3 million women from 21 prospective cohorts, 4,584 invasive epithelial ovarian cancers were identified and classified as highly aggressive (death in <1 year, n = 864), very aggressive (death in 1 to < 3 years, n = 1,390), moderately aggressive (death in 3 to < 5 years, n = 639), and less aggressive (lived 5+ years, n = 1,691). Using competing risks Cox proportional hazards regression, we assessed heterogeneity of associations by tumor aggressiveness for all cases and among serous and endometrioid/clear cell tumors. Associations between parity (p_het = 0.01), family history of ovarian cancer (p_het = 0.02), body mass index (BMI; p_het ≤ 0.04) and smoking (p_het < 0.01) and ovarian cancer risk differed by aggressiveness. A first/single pregnancy, relative to nulliparity, was inversely associated with highly aggressive disease (HR: 0.72; 95% CI [0.58-0.88]), no association was observed for subsequent pregnancies (per pregnancy, 0.97 [0.92-1.02]). In contrast, first and subsequent pregnancies were similarly associated with less aggressive disease (0.87 for both). Family history of ovarian cancer was only associated with risk of less aggressive disease (1.94 [1.47-2.55]). High BMI (≥35 vs. 20 to < 25 kg/m² , 1.93 [1.46-2.56] and current smoking (vs. never, 1.30 [1.07-1.57]) were associated with increased risk of highly aggressive disease. Results were similar within histotypes. Ovarian cancer risk factors may be directly associated with subtypes defined by tumor aggressiveness, rather than through differential effects on histology. Studies to assess biological pathways are warranted.

Autophagy Is Indispensable for the Self-Renewal and Quiescence of Ovarian Cancer Spheroid Cells with Stem Cell-Like Properties

Epithelial ovarian cancer has the highest mortality rate of all gynecologic cancers. Cancer stem cells are considered to be the initiating cells of tumors. It is known that spheroid culture promotes ovarian cancer cells to acquire stem cell characteristics and to become stem cell-like. But the mechanisms remain largely unclear. Our data show that autophagy is sustainably activated in ovarian cancer spheroid cells. Inhibition of autophagy by knockdown of ATG5 abolishes the self-renewal ability of ovarian cancer spheroid cells. Knockdown of ATG5 prevents ovarian cancer spheroid cells to enter quiescent state. Autophagy is critical for quiescent ovarian cancer spheroid cells to reenter the cell cycle because rapamycin can promote quiescent ovarian cancer spheroid cells to form colonies on soft agar and knockdown of ATG5 can arrest ovarian cancer cells in G0/G1. Autophagy and NRF2 form a positive feedback regulation loop to regulate reactive oxygen species (ROS) levels in ovarian cancer spheroid cells. The optimal ROS level, neither too high nor too low, facilitates the self-renewal marker, NOTCH1, to reach to the highest level. Bafilomycin A1 can impair the self-renewal of ovarian cancer spheroid cells by disturbing ROS levels.

Anticancer Activity of Metformin, an Antidiabetic Drug, Against Ovarian Cancer Cells Involves Inhibition of Cysteine-Rich 61 (Cyr61)/Akt/Mammalian Target of Rapamycin (mTOR) Signaling Pathway

Background

Ovarian cancer is considered one of the lethal cancers responsible for high mortality and morbidity across the world. The prognosis and the survival rate of ovarian cancer is far from decent. Cysteine-rich 61 (Cyr61) also known as CCN1, is a member of CCN-family of growth factors, reported to be significantly overexpressed in several malignancies which include, but are not limited to, ovarian cancer. Recent studies have revealed that women with type 2 diabetes mellitus have an elevated risk of ovarian cancer. Hence, administration of an antidiabetic drug with anticancer effects such as metformin may act as an effective therapeutic regime against ovarian cancer.

Material/Methods

Cell viability and apoptosis were examined by MTT and Annexin V/PI double staining respectively. Cell migration was determined by Boyden Chamber assay. Transient knockdown of Cyr61 in ovarian cancer cells was achieved by transecting the cells with siRNA for Cyr61using Lipofectamine 2000.

Results

Our results indicated that treatment of ovarian cancer cells with metformin caused significant downregulation of Cyr61 protein expression levels ultimately favoring apoptosis. Transient knockdown of Cyr61 resulted in the inhibition of cell proliferation and migration. This was also associated with the concomitant downregulation of pAkt and pmTOR confirming the role of Cyr61 as an upstream modulator of Akt signaling. Conversely the extracellular supplementation of recombinant Cyr61 attenuates the cytotoxic properties of metformin in ovarian cancer cells.

Conclusions

Taken together, we concluded that metformin exhibits anticancer effects and Cyr61 acts as a direct target for metformin in ovarian cancer cells.

Familial Ovarian Cancer Clusters with Other Cancers

Familial risk of ovarian cancer is well-established but whether ovarian cancer clusters with other cancers and the clusters differ by histology remains uncertain. Using data from the Swedish Family-Cancer Database, we explored familial associations of ovarian cancer with other cancers with a novel approach; relative risk for (histology-specific) ovarian cancer was estimated in families with patients affected by other cancers, and conversely, risks for other cancers in families with (histology-specific) ovarian cancer patients. Eight discordant cancers were associated with ovarian cancer risk, of which family history of breast cancer showed a dose-response (P-trend <0.0001). Conversely, risks of eight types of cancer increased in families with ovarian cancer patients, and dose-responses were shown for risks of liver (P-trend = 0.0083) and breast cancers (P-trend <0.0001) and cancer of unknown primary (P-trend = 0.0157). Some cancers were only associated with histology-specific ovarian cancers, e.g. endometrial cancer was only associated with endometrioid type but with highest significance. Novel associations with virus-linked cancers of the nose and male and female genitals were found. The results suggest that ovarian cancer shares susceptibility with a number of other cancers. This might alert genetic counselors and challenge approaches for gene and gene-environment identification.

One-Carbon Metabolism: Biological Players in Epithelial Ovarian Cancer

Metabolism is deeply involved in cell behavior and homeostasis maintenance, with metabolites acting as molecular intermediates to modulate cellular functions. In particular, one-carbon metabolism is a key biochemical pathway necessary to provide carbon units required for critical processes, including nucleotide biosynthesis, epigenetic methylation, and cell redox-status regulation. It is, therefore, not surprising that alterations in this pathway may acquire fundamental importance in cancer onset and progression. Two of the major actors in one-carbon metabolism, folate and choline, play a key role in the pathobiology of epithelial ovarian cancer (EOC), the deadliest gynecological malignancy. EOC is characterized by a cholinic phenotype sustained via increased activity of choline kinase alpha, and via membrane overexpression of the alpha isoform of the folate receptor (FRα), both of which are known to contribute to generating regulatory signals that support EOC cell aggressiveness and proliferation. Here, we describe in detail the main biological processes associated with one-carbon metabolism, and the current knowledge about its role in EOC. Moreover, since the cholinic phenotype and FRα overexpression are unique properties of tumor cells, but not of normal cells, they can be considered attractive targets for the development of therapeutic approaches.

Gynaecological cancers and leptin: A focus on the endometrium and ovary

Obesity has an influence on the risk and prognosis of different types of cancers of the female reproductive tract. In the uterus, a common site for neoplasms is the endometrium, the inner lining tissue. Generally, obesity has been documented to be involved in endometrioid carcinoma of the endometrium. Obesity may influence the cancer risk by various mechanisms such as chronic inflammation, dysregulation of sex hormones and abnormal secretion of hormone-like cytokines or adipokines from adipose tissue. One of the important pro-inflammatory adipokines is leptin, which acts via its transmembrane receptors (Ob-R). In normal conditions, leptin functions in the hypothalamic anorexigenic pathway to maintain the energy homeostasis. Conversely, in obesity, leptin participates in the pro-inflammatory processes. Several clinical studies have suggested that leptin and Ob-R play a role in the pathological processes of endometrial cancer. In different endometrial cancer cell lines, laboratory findings also have demonstrated leptin's link to various neoplastic phenomena such as cellular proliferation, angiogenesis, and oestrogenic activity. Furthermore, endometrial cancer risk could be increased in ovarian pathology like polycystic ovary syndrome, which is commonly associated with obesity. It is noteworthy that leptin participates in both physiological and pathological conditions of the ovary. Leptin has shown pro-tumorigenic effects in both in-vitro and in-vivo studies. Generally, reduced serum leptin levels have been observed in ovarian cancer patients. However, overexpression of leptin and Ob-R in ovarian cancer tissue has indicated aggressive disease. Understanding the role of leptin-related intracellular signalling pathways in tumour development could be helpful in early cancer detection.

The impact on high-grade serous ovarian cancer of obesity and lipid metabolism-related gene expression patterns: the underestimated driving force affecting prognosis

To investigate whether specific obesity/metabolism‐related gene expression patterns affect the survival of patients with ovarian cancer. Clinical and genomic data of 590 samples from the high‐grade ovarian serous carcinoma (HGOSC) study of The Cancer Genome Atlas (TCGA) and 91 samples from the Australian Ovarian Cancer Study were downloaded from the International Cancer Genome Consortium (ICGC) portal. Clustering of mRNA microarray and reverse‐phase protein array (RPPA) data was performed with 83 consensus driver genes and 144 obesity and lipid metabolism‐related genes. Association between different clusters and survival was analyzed with the Kaplan–Meier method and a Cox regression. Mutually exclusive, co‐occurrence and network analyses were also carried out. Using RNA and RPPA data, it was possible to identify two subsets of HGOSCs with similar clinical characteristics and cancer driver mutation profiles (e.g. TP53), but with different outcome. These differences depend more on up‐regulation of specific obesity and lipid metabolism‐related genes than on the number of gene mutations or copy number alterations. It was also found that CD36 and TGF‐ß are highly up‐regulated at the protein levels in the cluster with the poorer outcome. In contrast, BSCL2 is highly up‐regulated in the cluster with better progression‐free and overall survival. Different obesity/metabolism‐related gene expression patterns constitute a risk factor for prognosis independent of the therapy results in the Cox regression. Prognoses were conditioned by the differential expression of obesity and lipid metabolism‐related genes in HGOSCs with similar cancer driver mutation profiles, independent of the initial therapeutic response.

Case-control study of metabolic syndrome and ovarian cancer in Chinese population

Background

Recent studies have proved metabolic syndrome (MetS) was linked to cancer risks. However, few data has examined the relationship between MetS and epithelial ovarian cancer (EOC).

Methods

We conducted a population-based case-control study in Tianjin Medical University Cancer Institute and Hospital, China (2010–2015) that enrolled 573 EOC patients and 1146 matched controls. Data were collected through in-person interviews, anthropometric measurement, and 8-h fasting bloods drawn. MetS was estimated by Chinese Diabetes Society (CDS) definition requiring presence of ≥3 of the following risk factors: 1) body mass index (BMI) ≥25.0 kg/m²,2) fasting plasma glucose ≥6.1 mmol/L or 2-h plasma glucose ≥ 7.8 mmol/L, 3) systolic blood pressure ≥140 mmHg or diastolic blood pressure ≥90 mmHg, 4) triglyceride (TG) ≥1.70 mmol/L or high-density lipoprotein cholesterol (HDL-C) < 1.0 mmol/L. Statistics were completed using chi-square tests and logistic regression analysis. The survival analysis was conducted by the Kaplan-Meier method and Cox proportional hazard regression models.

Results

MetS was significantly more prevalent among EOC (25.13%) than controls (6.89%). A statistically significant increase risk for EOC was observed for MetS (multivariable-adjusted OR = 3.187; 95% CI: 2.135–4.756). MetS was significantly associated with histological grade (P < 0.001), FIGO stage (P = 0.003), and lymph node (LN) status (P = 0.002) of EOC. In binary logistic regression analysis, the presence of MetS predicts the risk of advanced FIGO stage (OR = 2.155, 95% CI: 1.327–3.498, P = 0.002), lower differentiation (OR = 2.472, 95% CI: 1.164–5.250, P = 0.019), and LN metastasis (OR = 2.590, 95% CI: 1.089–6.160, P = 0.031) of EOC. Moreover, MetS is the independent factor for the evaluation of PFS and OS of EOC patients (both of them P < 0.001) in Cox proportional hazard model.

Conclusion

MetS is obviously related to increased EOC risk. EOC patients with MetS in Chinese population were found to have statistically significant tumor advanced stage, low differentiation, LN metastasis and poor prognosis.