The prognostic value and clinicopathological significance of CD44 expression in ovarian cancer: a meta-analysis

Defining the Role of Metastasis-Initiating Cells in Promoting Carcinogenesis in Ovarian Cancer

Ovarian cancer is the deadliest gynecological malignancy with a high prevalence of transcoelomic metastasis. Metastasis is a multi-step process and only a small percentage of cancer cells, metastasis-initiating cells (MICs), have the capacity to finally establish metastatic lesions. These MICs maintain a certain level of stemness that allows them to differentiate into other cell types with distinct transcriptomic profiles and swiftly adapt to external stresses. Furthermore, they can coordinate with the microenvironment, through reciprocal interactions, to invade and establish metastases. Therefore, identifying, characterizing, and targeting MICs is a promising strategy to counter the spread of ovarian cancer. In this review, we provided an overview of OC MICs in the context of characterization, identification through cell surface markers, and their interactions with the metastatic niche to promote metastatic colonization.

The Therapeutic Effects of DDP/CD44-shRNA Nanoliposomes in AMF on Ovarian Cancer

BACKGROUND

Globally, ovarian cancer is one of the most common gynecological malignant tumors, and the overall curative effect has been unsatisfactory for years. Exploring and investigating novel therapeutic strategy for ovarian cancer are an imperative need.

METHODS

Using manganese zinc ferrite nanoparticles (PEG-MZF-NPs) as gene transferring vector and drug delivery carrier, a new combinatorial regimen for the target treatment of ovarian cancer by integrating CD44-shRNA, DDP (cisplatin) and magnetic fluid hyperthermia (MFH) together was designed and investigated in vivo and in vitro in this study.

RESULTS

PEG-MZF-NPs/DDP/CD44-shRNA nanoliposomes were successfully prepared, and TEM detection indicated that they were 15-20 nm in diameter, with good magnetothermal effect in AMF, similar to the previously prepared PEG-MZF-NPs. Under the action of AMF, PEG-MZF-NPs/shRNA/DDP nanoliposomes effectively inhibited ovarian tumors' growth, restrained the cancer cells' proliferation and invasion, and promoted cell apoptosis. VEGF, survivin, BCL-2, and BCL-xl proteins significantly decreased, while caspase-3 and caspase-9 proteins markedly increased both in vitro and in vivo, far better than any of the individual therapies did. Moreover, no significant effects were found on bone marrow hematopoiesis and liver and kidney function of nude mice intervened by the combinatorial therapeutic regimen.

CONCLUSION

In the present study, we developed PEG-MZF-NPs/DDP/CD44-shRNA magnetic nanoliposomes and inaugurated an integrated therapy through the synergistic effect of MFH, gene therapy, and chemotherapy, and it shows a satisfactory therapeutic effect on ovarian cancer in vitro and in vivo, much better than any single treatment regimen did, with no significant side effects. This study provides a new promising method for ovarian cancer treatment.

A Novel Defined Risk Signature of the Ferroptosis-Related Genes for Predicting the Prognosis of Ovarian Cancer

Ferroptosis is an iron-dependent, regulated form of cell death, and the process is complex, consisting of a variety of metabolites and biological molecules. Ovarian cancer (OC) is a highly malignant gynecologic tumor with a poor survival rate. However, the predictive role of ferroptosis-related genes in ovarian cancer prognosis remains unknown. In this study, we demonstrated that the 57 ferroptosis-related genes were expressed differently between ovarian cancer and normal ovarian tissue, and based on these genes, all OC cases can be well divided into 2 subgroups by applying consensus clustering. We utilized the least absolute shrinkage and selection operator (LASSO) cox regression model to develop a multigene risk signature from the TCGA cohort and then validated it in an OC cohort from the GEO database. A 5-gene signature was built and reveals a favorable predictive efficacy in both TCGA and GEO cohort (P < 0.001 and P = 0.03). The GO and KEGG analysis revealed that the differentially expressed genes (DEGs) between the low- and high-risk subgroup divided by our risk model were associated with tumor immunity, and lower immune status in the high-risk group was discovered. In conclusion, ferroptosis-related genes are vital factors predicting the prognosis of OC and could be a novel potential treatment target.

Primary Ovarian Tumors With Lymphogenic and Hematogenic Metastasis Express High MMP-14, Which Colocalizes With Highly Sulfated Chondroitin Sulfate in the Stroma

Lymphogenic and hematogenic metastases are uncommon in ovarian cancer, especially at presentation. We hypothesized that MMP-14 and MMP-2, CD44, and highly sulfated chondroitin sulfate (CS-E) may be overexpressed in tumors with these metastatic patterns. These molecules are all present in the ovarian tumor microenvironment, wherein they may interact. In an ovarian cancer cohort of 44 patients with metastases in lymph nodes, spleen, and/or liver, the presence of MMP-14, MMP-2, CD44, and CS-E in both the primary tumor and the metastases was determined with immunohistochemistry and related to clinical characteristics. Immunohistochemical expression was found for MMP-14 in all primary tumors as well as in all metastases and for MMP-2 expression in most of the samples. Most primary tumors with synchronous metastases were positive for CS-E, as well as most primary tumors with metachronous lymphogenic metastases. The expression of the MMPs and CS-E in the stroma seemed to colocalize. For CD44 immunohistochemical expression, this relationship was not found. Epithelial MMP-14 on the one hand and stromal CS-E on the other hand seem to be essential players in ovarian cancer with lymphogenic and hematogenic metastases. CD44 expression is not correlated with the other markers. More research on the interaction of these molecules and their role in the process of dissimination of disease is warranted.

Prognostic Value of CD44 and Its Isoforms in Advanced Cancer: A Systematic Meta-Analysis With Trial Sequential Analysis

Objective: Cancer stem cell marker CD44 and its variant isoforms (CD44v) may be correlated with tumor growth, metastasis, and chemo-radiotherapy resistance. However, the prognostic power of CD44 and CD44v in advanced cancer remains controversial. Therefore, the purpose of our study was to generalize the prognostic significance of these cancer stem cell markers in advanced cancer patients.

Methods: Hazard ratios (HRs) with 95% confidence intervals (95% CIs) were calculated from multivariable analysis to assess the associations among CD44, CD44v6, and CD44v9 positivity and overall survival (OS), disease-free survival (DFS), progression-free survival (PFS), cancer-specific survival (CSS), and recurrence-free survival (RFS). Trial sequential analysis (TSA) was also conducted.

Results: We included 15 articles that reported on 1,201 patients with advanced cancer (CD44: nine studies with 796 cases, CD44v6: three studies with 143 cases, and CD44v9: three studies with 262 cases). CD44 expression was slightly linked to worse OS (HR = 2.03, P = 0.027), but there was no correlation between CD44 expression and DFS, RFS, or PFS. Stratified analysis showed that CD44 expression was not correlated with OS at ≥5 years or OS in patients receiving adjuvant therapy. CD44v6 expression was not associated with OS. CD44v9 expression was closely associated with poor 5-years CSS in patients treated with chemo/radiotherapy (HR = 3.62, P < 0.001). However, TSA suggested that additional trials were needed to confirm these conclusions.

Conclusions: CD44 or CD44v9 might be novel therapeutic targets for improving the treatment of advanced cancer patients. Additional prospective clinical trials are strongly needed across different cancer types.

Ovarian cancer stem cell: A potential therapeutic target for overcoming multidrug resistance

The cancer stem cell (CSC) model encompasses an advantageous paradigm that in recent decades provides a better elucidation for many important biological aspects of cancer initiation, progression, metastasis, and, more important, development of multidrug resistance (MDR). Such several other hematological malignancies and solid tumors and the identification and isolation of ovarian cancer stem cells (OV-CSCs) show that ovarian cancer also follows this hierarchical model. Gaining a better insight into CSC-mediated resistance holds promise for improving current ovarian cancer therapies and prolonging the survival of recurrent ovarian cancer patients in the future. Therefore, in this review, we will discuss some important mechanisms by which CSCs can escape chemotherapy, and then review the recent and growing body of evidence that supports the contribution of CSCs to MDR in ovarian cancer.

Can Stemness and Chemoresistance Be Therapeutically Targeted via Signaling Pathways in Ovarian Cancer?

Ovarian cancer is the most lethal gynecological malignancy. Poor overall survival, particularly for patients with high grade serous (HGS) ovarian cancer, is often attributed to late stage at diagnosis and relapse following chemotherapy. HGS ovarian cancer is a heterogenous disease in that few genes are consistently mutated between patients. Additionally, HGS ovarian cancer is characterized by high genomic instability. For these reasons, personalized approaches may be necessary for effective treatment and cure. Understanding the molecular mechanisms that contribute to tumor metastasis and chemoresistance are essential to improve survival rates. One favored model for tumor metastasis and chemoresistance is the cancer stem cell (CSC) model. CSCs are cells with enhanced self-renewal properties that are enriched following chemotherapy. Elimination of this cell population is thought to be a mechanism to increase therapeutic response. Therefore, accurate identification of stem cell populations that are most clinically relevant is necessary. While many CSC identifiers (ALDH, OCT4, CD133, and side population) have been established, it is still not clear which population(s) will be most beneficial to target in patients. Therefore, there is a critical need to characterize CSCs with reliable markers and find their weaknesses that will make the CSCs amenable to therapy. Many signaling pathways are implicated for their roles in CSC initiation and maintenance. Therapeutically targeting pathways needed for CSC initiation or maintenance may be an effective way of treating HGS ovarian cancer patients. In conclusion, the prognosis for HGS ovarian cancer may be improved by combining CSC phenotyping with targeted therapies for pathways involved in CSC maintenance.

Astragalus polysaccharides increase the sensitivity of SKOV3 cells to cisplatin

BACKGROUND

Multidrug resistance in malignant tumours hinders the treatment of tumours. Studies showed that astragalus polysaccharides (APS), one major active ingredient of astragalus, enhanced the sensitivity of non-small cell lung cancer and liver cancer cells to chemotherapeutic drug. However, the effect of APS on ovarian cancer is still unclear. In this study, we will examine the sensitizing effect of APS on SKOV3 cells to cisplatin and explore the possible mechanism.

METHODS

MTT assay was employed to examine the viability of SKOV3 after treatment with APS and cisplatin. The cell apoptosis rate was determined by flow cytometry. The expression of Bax, Bcl-2, Caspase-3, and c-Jun N-terminal kinases 1/2 (JNK1/2) was measured using Western blotting and RT-PCR.

RESULTS

APS synergistically promoted the inhibitory effect of cisplatin on SKOV3 cell viability. Flow cytometry showed that APS promoted cisplatin-induced apoptosis of SKOV3 cell lines. Further studies showed that APS down-regulated the expression of Bcl2, increased the expression of Bax and caspase 3 and activated JNK1/2 signalling pathway. The JNK inhibitors significantly rescued the proliferation inhibition induced by the drugs.

CONCLUSIONS

Astragalus polysaccharides increased the sensitivity of SKOV3 cells to cisplatin potentially by activating the JNK pathway. The apoptosis-related genes may contribute to the process. Thus, APS may be useful for the treatment of ovarian cancer as an enhancer of chemosensitivity.

Aberrant SERPINE1 DNA methylation is involved in carboplatin induced epithelial-mesenchymal transition in epithelial ovarian cancer

AIM

Resistance to platinum-based therapeutic agents is the major contributor to epithelial ovarian cancer (EOC) mortality. There is an urgent need to better understand the underlying mechanisms. Here we investigated the role of serpins in EOC chemoresistance and related mechanisms, and found that SERPINE1 played an important role in chemoresistance in A2780cp cells.

MATERIALS AND METHODS

A2780cp and A2780s cells were used in our study. Microarray screening was used to identify the gene expression change under carboplatin treatment. A cell-counting kit-8 was used to detect the sensitivity of ovarian cancer cells after treatment. The expression of SERPINE1 was silenced by siRNA. The levels of SERPINE1 and epithelial-mesenchymal transition (EMT)-related proteins were confirmed by Western blot. MassArray EpiTYPER quantitative DNA methylation analysis was introduced to evaluate the methylation of the promoter of SERPINE1.

RESULTS

Microarray data showed that SERPINE1 and SERPINE2 increased most dramatically under carboplatin treatment in A2780cp cells. Carboplatin treatment could significantly increase the expression of SERPINE1 and induce the EMT process, with decreased expression of E-cadherin and increased expression of Vimentin, Snail and Twist. Knockdown of SERPINE1, but not SERPINE2, in A2780cp cells could inhibit the EMT process. We also found that hypomethylation in the promoter of SERPINE1 might result in the increased expression of SERPINE1 and subsequent EMT process in A2780cp cells.

CONCLUSION

Our study suggested that SERPINE1 may be a promising therapeutic target for chemoresistance.

MMP-14 and CD44 in Epithelial-to-Mesenchymal Transition (EMT) in ovarian cancer

Background

To investigate the expression of MMP-14 and CD44 as well as epithelial-to-mesenchymal transition(EMT)-like changes in ovarian cancer and to determine correlations with clinical outcome.

Methods

In 97 patients with ovarian cancer, MMP-14 and CD44 expression as determined by immunohistochemistry was investigated in relation to EMT-like changes. To determine this, immunohistochemical staining of E-cadherin and vimentin was performed.

Results

Patients with expression of both MMP-14 and CD44 in their tumors had a poor prognosis despite complete debulking. Serous histology in advanced-stage tumors (FIGO IIB-IV) correlated with CD44 (rho .286, p < 0.01). Also, CD44 correlated with percentage vimentin expression (rho .217, p < 0.05).

In logistic regression analysis with complete debulking as the outcome parameter, CD44 expression was found to be significant (OR 3,571 (95 % Confidence Interval 1,112–11,468) p = 0.032), though this was not the case for MMP-14 and EMT parameters.

Conclusion

The subgroup of patients with double expression of MMP-14 and CD44 had a poor prognosis despite complete debulking. Serous subtype in advanced-stage patients and CD44 expression were found to be correlated with vimentin expression, and CD44 expression was found to be significantly correlated with complete debulking. However, a significant correlation between EMT and clinical parameters was not found.