The duplicitous origin of ovarian cancer

The role of resveratrol, Sirtuin1 and RXRα as prognostic markers in ovarian cancer

Objective

Ovarian cancer is the most lethal gynecologic cancer. Resveratrol (RSV) is known to alter metabolism in cancer. It affects the nuclear retinoid-X-receptor (RXR), which implies a modulating effect of RXR to gynaecologic cancers. Furthermore, RSV targets Sirtuin1 (Sirt1), a histone deacetylase.

Study design

123 tissue samples of patients with serous or mucinous ovarian cancer were examined for expression of Sirt1 and RXR. Ovarian cell lines were treated with RSV and consequences on viability and apoptosis were evaluated. The influence of RSV to Sirt1 and RXR expression was analyzed by western blotting

Results

A correlation of nuclear Sirt1 and RXRα expression could be detected (p = 0.006). Co-expression of nuclear RXRα and cytoplasmic (p = 0.026) or nuclear (p = 0.041) Sirt1 was associated with significantly increased overall survival in advanced tumour stages. Viability was decreased in all cell lines after stimulation with resveratrol, while cell apoptosis was increased. RSV treatment led to significant lower Sirt1 expression in A2780 cells (p = 0.025) and significant increased RXR expression in cisA2780 cells (p = 0.012)

Conclusion

In order to use RSV as medical target, studies could be developed to improve the understanding of drug resistance mechanisms and consequently improve treatment outcome.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00404-021-06262-w.

Substrate Stiffness Modulates the Growth, Phenotype, and Chemoresistance of Ovarian Cancer Cells

Mechanical factors in the tumor microenvironment play an important role in response to a variety of cellular activities in cancer cells. Here, we utilized polyacrylamide hydrogels with varying physical parameters simulating tumor and metastatic target tissues to investigate the effect of substrate stiffness on the growth, phenotype, and chemotherapeutic response of ovarian cancer cells (OCCs). We found that increasing the substrate stiffness promoted the proliferation of SKOV-3 cells, an OCC cell line. This proliferation coincided with the nuclear translocation of the oncogene Yes-associated protein. Additionally, we found that substrate softening promoted elements of epithelial-mesenchymal transition (EMT), including mesenchymal cell shape changes, increase in vimentin expression, and decrease in E-cadherin and β-catenin expression. Growing evidence demonstrates that apart from contributing to cancer initiation and progression, EMT can promote chemotherapy resistance in ovarian cancer cells. Furthermore, we evaluated tumor response to standard chemotherapeutic drugs (cisplatin and paclitaxel) and found antiproliferation effects to be directly proportional to the stiffness of the substrate. Nanomechanical studies based on atomic force microscopy (AFM) have revealed that chemosensitivity and chemoresistance are related to cellular mechanical properties. The results of cellular elastic modulus measurements determined by AFM demonstrated that Young's modulus of SKOV-3 cells grown on soft substrates was less than that of cells grown on stiff substrates. Gene expression analysis of SKOV-3 cells showed that mRNA expression can be greatly affected by substrate stiffness. Finally, immunocytochemistry analyses revealed an increase in multidrug resistance proteins, namely, ATP binding cassette subfamily B member 1 and member 4 (ABCB1 and ABCB4), in the cells grown on the soft gel resulting in resistance to chemotherapeutic drugs. In conclusion, our study may help in identification of effective targets for cancer therapy and improve our understanding of the mechanisms of cancer progression and chemoresistance.

Associations of preoperative serum high-density lipoprotein cholesterol and low-density lipoprotein cholesterol levels with the prognosis of ovarian cancer

BACKGROUND

The effect of serum lipids on ovarian cancer is controversial. We conducted this study to evaluate the prognostic value of preoperative plasma lipid profile in patients with ovarian cancer.

METHODS

The medical records of 156 epithelial ovarian cancer patients who underwent surgical resection in our department were retrospectively reviewed and analyzed. Serum lipids profiles, including total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), triglyceride (TG), apolipoprotein A-I (apoA-I), apolipoprotein B (apoB) and clinicopathologic data, were analyzed. Cox proportional hazards regression analyses and Kaplan-Meier method were performed to evaluate the overall survival (OS) and progression-free survival (PFS).

RESULTS

Multivariable Cox regression analysis found that preoperative higher LDL-C level was significantly associated with worse OS (HR 2.088, 95% CI 1.052-4.147, p = 0.035), whereas higher HDL-C level showed significant association with better PFS (HR 0.491, 95% CI 0.247-0.975, p = 0.042). Further Kaplan-Meier survival analysis demonstrated that OS was longer for patients with low levels of LDL-C (< 2.76 mmol/L) compared to those with high levels of LDL-C (≥ 2.76 mmol/L) (P = 0.028), and PFS was better for patients with high levels of HDL-C (≥ 1.19 mmol/L) compared to those with low levels of HDL-C (< 1.19 mmol/L) (P = 0.001).

CONCLUSIONS

Preoperative HDL-C and LDL-C levels are significant predictors of clinical outcome in patients with epithelial ovarian cancer.

Chemoresistance in Ovarian Cancer: Prospects for New Drugs

This review focuses on the conventional treatment, signaling pathways and various reasons for drug resistance with an understanding of novel methods that can lead to effective therapies. Ovarian cancer is amongst the most common gynecological and lethal cancers in women affecting different age groups (20-60). The survival rate is limited to 5 years due to diagnosis in subsequent stages with a reoccurrence of tumor and resistance to chemotherapeutic therapy. The recent clinical trials use the combinatorial treatment of carboplatin and paclitaxel on ovarian cancer after the cytoreduction of the tumor. Predominantly, patients are responsive initially to therapy and later develop metastases due to drug resistance. Chemotherapy also leads to drug resistance causing enormous variations at the cellular level. Multifaceted mechanisms like drug resistance are associated with a number of genes and signaling pathways that process the proliferation of cells. Reasons for resistance include epithelial-mesenchyme, DNA repair activation, autophagy, drug efflux, pathway activation, and so on. Determining the routes on the molecular mechanism that target chemoresistance pathways are necessary for controlling the treatment and understanding efficient drug targets can open light on improving therapeutic outcomes. The most common drug used for ovarian cancer is Cisplatin that activates various chemoresistance pathways, ultimately causing drug resistance. There have been substantial improvements in understanding the mechanisms of cisplatin resistance or chemo sensitizing cisplatin for effective treatment. Therefore, using therapies that involve a combination of phytochemical or novel drug delivery system would be a novel treatment for cancer. Phytochemicals are plant-derived compounds that exhibit anti-cancer, anti-oxidative, anti-inflammatory properties and reduce side effects exerted by chemotherapeutics.

A Study of CD44 Positive Cancer Cells in Epithelial Ovarian Cancer and their Correlation with P53 And Ki67

Context  Epithelial ovarian carcinomas are one of the most common lethal gynecological malignancies. There is no specific symptom or biomarker for detection of this malignancy in early stage. So, the advanced stage, nature of frequent recurrences, and resistance to chemotherapies make it very difficult to deliver proper treatment to patients. Efforts are on to identify the presence of cancer stem cell by using a specific biomarker in epithelial ovarian cancer in the early stage.

Objectives  This study aims to identify the CD44 positive cancer cells in epithelial ovarian carcinoma of different histopathological types. It also intends to correlate the expression of CD44 with the expression of p53 and Ki67.

Materials and Methods  Sections from diagnosed specimens of ovarian epithelial neoplasm had been fixed in 10% formalin and embedded in paraffin, and they were used for immunohistochemical (IHC) staining for CD44, p53, and Ki67, using a peroxidase kit with mouse monoclonal antibodies. Then, the slides were evaluated for both tumor cell percentage and intensity of immunoreactivity.

Statistical Analysis  Chi-square had been used to find the significance of study. Significance level was considered at p value < 0.05

Results  In this study, 40 patients were included in a period of one and a half years. The present study suggested that the levels of CD44 expression were increased in epithelial ovarian cancer compared to borderline tumor. CD44 was positively correlated with the ki67 expression and tumor grade. High-grade serous, mucinous, and endometrioid tumors were associated with high CD44 expression. Positivity of CD44 was found significantly higher in case of positive status of p53 (z = 3.65; p < 0.0001).

Conclusion  We can correlate CD44 positive cancer stem cells with grade of ovarian carcinomas, but for prognostic significance and therapeutic applications, more corroborative and multicentric works in this field are needed. CD44 can be targeted for therapy in recurrent and resistant cases of ovarian cancer.

Characteristics of CD133-Sustained Chemoresistant Cancer Stem-Like Cells in Human Ovarian Carcinoma

Cancer stem cells (CSCs) are considered to be the origin of ovarian cancer (OC) development, recurrence, and chemoresistance. We investigated changes in expression levels of the CSC biomarker, cluster of differentiation 133 (CD133), from primary OC cell lines to induction of CSC-spheres in an attempt to explore the mechanisms related to modulation of stemness, drug resistance, and tumorigenesis in CSCs, thus facilitating the search for new therapeutics for OC. The effect of CD133 overexpression on the induction of CSC properties was evaluated by sphere-forming assays, RT-qPCR, flow cytometry, cell viability assays, and in vivo xenograft experiments. Moreover, the potential signaling molecules that participate in CD133 maintenance of stemness were screened by RNA-sequencing. CD133 expression was upregulated during OCSC induction and chemotherapeutic drug treatment over time, which increased the expressions of stemness-related markers (SOX2, OCT4, and Nanog). CD133 overexpression also promoted tumorigenesis in NOD/SCID mice. Several signalings were controlled by CD133 spheres, including extracellular matrix receptor interactions, chemokine signaling, and Wnt signaling, all of which promote cell survival and cell cycle progression. Our findings suggest that CD133 possesses the ability to maintain functional stemness and tumorigenesis of OCSCs by promoting cell survival signaling and may serve as a potential target for stem cell-targeted therapy of OC.

The value of systematic lymphadenectomy during debulking surgery in the treatment of ovarian cancer: a meta-analysis of randomized controlled trials

Background

The therapeutic value of systematic lymphadenectomy during debulking surgery for ovarian cancer remains controversial. We conduct this meta-analysis to evaluate the significance of systematic lymphadenectomy in patients treated with optimal cytoreduction for ovarian cancer.

Method

The PubMed, Medline, Embase, Cochrane Library and Web of Science databases were searched up to October 2019. Only English-language publications of randomized controlled trials (RCTs) that investigated the role of systematic lymphadenectomy in patients with ovarian cancer were selected for this analysis. For overall survival (OS) and progression-free survival (PFS), pooled hazard ratios (HR) with 95% confidence intervals (CIs) were calculated; for complications rate, we calculated pooled risk ratio (RR) with 95% confidence interval (CI). Statistical heterogeneity was assessed using both the I² and chi-square tests. In cases of I² being larger than 50%, a random-effect model was used, otherwise a fixed-effect model was used.

Results

Four RCTs involving 1607 patients were included in the present analysis. There was no difference in OS between systematic lymphadenectomy and unsystematic lymphadenectomy (HR = 1.00; 95% CI = 0.94, 1.07; p = 0.90). Similarly, no significant difference was observed in PFS between these two groups (HR = 0.97; 95% CI = 0.87, 1.08; p = 0.62). And postoperative complications occurred more frequently in the systematic lymphadenectomy group (RR = 1.50; 95% CI = 1.34, 1.68; p < 0.00001).

Conclusion

Systematic lymphadenectomy in patients with optimally cytoreduced ovarian cancer was not associated with longer overall or progression-free survival than unsystematic lymphadenectomy and was associated with a higher incidence of postoperative complications.

CK19 Promotes Ovarian Cancer Development by Impacting on Wnt/β-Catenin Pathway

Background

Epithelial ovarian cancer (EOC) is the most common type of ovarian cancer and is the most lethal gynecologic malignancy. Cytokeratin 19 (CK19) is a small type I cytokeratin. The aim of this study is to explore the functional role of CK19 and its underlying mechanism in EOC.

Methods

The expression levels of CK19 in EOC tissues were identified by Western blotting and RT-PCR assay. Transwell assay and CCK-8 proliferation assay were used to assess the invasion, migration and proliferation abilities of overexpressed or knockdown CK19 of ovarian cancer cells. We also detected the related genes of Wnt/β-catenin signal pathway, including β-catenin, TCF7, LEF1, c-MYC and cyclin D1 in the transfected ovarian cancer cells by Western blotting and RT-PCR assay.

Results

The results demonstrated that CK19 was upregulated in EOC tissue. CK19 was verified to promote the invasion, proliferation and migration of ovarian cancer cells. Additionally, CK19 activates the Wnt/β-catenin signaling pathway by upregulated β-catenin, TCF7, LEF1, c-MYC and cyclin D1.

Conclusions

In summary, this is the first study to investigate the role of CK19 in EOC. These findings provide a potential new therapeutic target for the clinical diagnosis and treatment of ovarian cancer.

Photodynamic therapy of cervical cancer by eradication of cervical cancer cells and cervical cancer stem cells

The heterogeneous nature of cancer puts cancer stem cells (CSCs) at the beating heart of the tumour. Because of their inherent characteristics of stemness, CSCs evade putative cancer therapies, resulting in treatment resistance or tumour recurrence after a seemingly successful treatment. To prevent treatment resistance and cancer recurrence, killing the beating heart of the tumour is of utmost importance. This study therefore, sought to determine the effect of Photodynamic Therapy (PDT) in eradicating cervical cancer and cervical CSCs. Cervical CSCs were isolated from a cervical adenocarcinoma cell line, HeLa cells, and grown in liquid medium incubated at 37° C, 5% CO₂ and 85% humidity. Increasing doses of AlPcS_mix photosensitizer were administered to both the total cell population and the isolated CSCs, and irradiated using 673.2 nm diode laser. Post-irradiation cellular changes were observed using biochemical assays and microscopy to determine the response of both the total cell population and the CSCs. Results showed a dose-dependent response of both cell populations to treatment, by demonstration of significant morphologic changes, increased cytotoxicity, and decreased cell viability and proliferation. The study suggested that PDT using AlPcS_mix is a very effective treatment method for the eradication of cervical cancer cells and cervical CSCs, in vitro.

The Role of Epithelial-to-Mesenchymal Plasticity in Ovarian Cancer Progression and Therapy Resistance

Ovarian cancer is the most lethal of all gynecologic malignancies and the eighth leading cause of cancer-related deaths among women worldwide. The main reasons for this poor prognosis are late diagnosis; when the disease is already in an advanced stage, and the frequent development of resistance to current chemotherapeutic regimens. Growing evidence demonstrates that apart from its role in ovarian cancer progression, epithelial-to-mesenchymal transition (EMT) can promote chemotherapy resistance. In this review, we will highlight the contribution of EMT to the distinct steps of ovarian cancer progression. In addition, we will review the different types of ovarian cancer resistance to therapy with particular attention to EMT-mediated mechanisms such as cell fate transitions, enhancement of cancer cell survival, and upregulation of genes related to drug resistance. Preclinical studies of anti-EMT therapies have yielded promising results. However, before anti-EMT therapies can be effectively implemented in clinical trials, more research is needed to elucidate the mechanisms leading to EMT-induced therapy resistance.

Evaluation of Microscopic Changes in Fallopian Tubes of BRCA Mutation Carriers by Morphometric Analysis of Histologic Slides: A Preliminary Pilot Study

Mutations in BRCA genes increase the risk of ovarian cancer, yet no method for early diagnosis is available. Some serous ovarian tumors are hypothesized to stem from cells of the fallopian tube fimbria. Using a novel method of computerized morphometry of the fimbrial epithelium, this study aimed to detect morphologic differences in noncancerous fimbriae between BRCA mutation carriers and noncarriers, and between healthy and serous ovarian cancer patients. Twenty-four fimbriae from healthy women (13 BRCA+, 11 BRCA-) and 21 fimbriae from women with serous ovarian cancer (10 BRCA+, 11 BRCA-), all reported as "normal" by hematoxylin and eosin examination, were subjected to computerized histomorphometric analysis. A Fast Fourier Transformation was applied to images of fimbrial epithelium and the Fast Fourier Transformation 2-dimensional frequency maps were subsequently quantified for nuclear orientation and planar distribution by a cooccurrence matrix analysis. Additional analysis of nuclear contour was applied to the fimbriae of the healthy women. Among the healthy women, significant differences were found in morphometric characteristics between the BRCA mutation carriers and noncarriers. Among the women with ovarian cancer, no significant differences were found between BRCA mutation carriers and noncarriers. Between healthy women and those with ovarian cancer, significant differences were detected, regardless of BRCA mutational status. A novel method, which combined Fast Fourier Transformation with cooccurrence matrix analysis, demonstrated differences in morphometric characteristics in the fimbriae between healthy and ovarian cancer patients, and between BRCA mutation carriers and noncarriers. The clinical significance of these observations should be investigated.

Ovarian Cancers: Genetic Abnormalities, Tumor Heterogeneity and Progression, Clonal Evolution and Cancer Stem Cells

Four main histological subtypes of ovarian cancer exist: serous (the most frequent), endometrioid, mucinous and clear cell; in each subtype, low and high grade. The large majority of ovarian cancers are diagnosed as high-grade serous ovarian cancers (HGS-OvCas). TP53 is the most frequently mutated gene in HGS-OvCas; about 50% of these tumors displayed defective homologous recombination due to germline and somatic BRCA mutations, epigenetic inactivation of BRCA and abnormalities of DNA repair genes; somatic copy number alterations are frequent in these tumors and some of them are associated with prognosis; defective NOTCH, RAS/MEK, PI3K and FOXM1 pathway signaling is frequent. Other histological subtypes were characterized by a different mutational spectrum: LGS-OvCas have increased frequency of BRAF and RAS mutations; mucinous cancers have mutation in ARID1A, PIK3CA, PTEN, CTNNB1 and RAS. Intensive research was focused to characterize ovarian cancer stem cells, based on positivity for some markers, including CD133, CD44, CD117, CD24, EpCAM, LY6A, ALDH1. Ovarian cancer cells have an intrinsic plasticity, thus explaining that in a single tumor more than one cell subpopulation, may exhibit tumor-initiating capacity. The improvements in our understanding of the molecular and cellular basis of ovarian cancers should lead to more efficacious treatments.

TWIST and ovarian cancer stem cells: implications for chemoresistance and metastasis

The transcription factor TWIST1 is a highly evolutionally conserved basic Helix-Loop-Helix (bHLH) transcription factor that functions as a master regulator of gastrulation and mesodermal development. Although TWIST1 was initially associated with embryo development, an increasing number of studies have shown TWIST1 role in the regulation of tissue homeostasis, primarily as a regulator of inflammation. More recently, TWIST1 has been found to be involved in the process of tumor metastasis through the regulation of Epithelial Mesenchymal Transition (EMT). The objective of this review is to examine the normal functions of TWIST1 and its role in tumor development, with a particular focus on ovarian cancer. We discuss the potential role of TWIST1 in the context of ovarian cancer stem cells and its influence in the process of tumor formation.