Reversing microtubule-directed chemotherapeutic drug resistance by co-delivering α2β1 inhibitor and paclitaxel with nanoparticles in ovarian cancer

Site-specific delivery of cisplatin and paclitaxel mediated by liposomes: A promising approach in cancer chemotherapy

The site-specific delivery of drugs, especially anti-cancer drugs has been an interesting field for researchers and the reason is low accumulation of cytotoxic drugs in cancer cells. Although combination cancer therapy has been beneficial in providing cancer drug sensitivity, targeted delivery of drugs appears to be more efficient. One of the safe, biocompatible and efficient nano-scale delivery systems in anti-cancer drug delivery is liposomes. Their particle size is small and they have other properties such as adjustable physico-chemical properties, ease of functionalization and high entrapment efficiency. Cisplatin is a chemotherapy drug with clinical approval in patients, but its accumulation in cancer cells is low due to lack of targeted delivery and repeated administration results in resistance development. Gene and drug co-administration along with cisplatin/paclitaxel have resulted in increased sensitivity in tumor cells, but there is still space for more progress in cancer therapy. The delivery of cisplatin/paclitaxel by liposomes increases accumulation of drug in tumor cells and impairs activity of efflux pumps in promoting cytotoxicity. Moreover, phototherapy along with cisplatin/paclitaxel delivery can increase potential in tumor suppression. Smart nanoparticles including pH-sensitive nanoparticles provide site-specific delivery of cisplatin/paclitaxel. The functionalization of liposomes can be performed by ligands to increase targetability towards tumor cells in mediating site-specific delivery of cisplatin/paclitaxel. Finally, liposomes can mediate co-delivery of cisplatin/paclitaxel with drugs or genes in potentiating tumor suppression. Since drug resistance has caused therapy failure in cancer patients, and cisplatin/paclitaxel are among popular chemotherapy drugs, delivery of these drugs mediates targeted suppression of cancers and prevents development of drug resistance. Because of biocompatibility and safety of liposomes, they are currently used in clinical trials for treatment of cancer patients. In future, the optimal dose of using liposomes and optimal concentration of loading cisplatin/paclitaxel on liposomal nanocarriers in clinical trials should be determined.

Perspectives of using microRNA-loaded nanocarriers for epigenetic reprogramming of drug resistant colorectal cancers

Epigenetic regulation by microRNAs (miRs) demonstrated a promising therapeutic potential of these molecules to regulate genetic activity in different cancers, including colorectal cancers (CRCs). The RNA-based therapy does not change genetic codes in tumor cells but can silence oncogenes and/or reactivate inhibited tumor suppressor genes. In many cancers, specific miRs were shown to promote or stop tumor progression. Among confirmed and powerful epigenetic regulators of colon carcinogenesis and development of resistance are onco-miRs, which include let-7, miR-21, miR-22, miR-23a, miR-27a, miR-34, miR-92, miR-96, miR-125b, miR-135b, miR-182, miR-200c, miR-203, miR-221, miR-421, miR-451, and others. Moreover, various tumor-suppressor miRs (miR-15b-5b, miR-18a, miR-20b, miR-22, miR-96, miR-139-5p, miR-145, miR-149, miR-197, miR-199b, miR-203, miR-214, miR-218, miR-320, miR-375-3p, miR-409-3p, miR-450b-5p, miR-494, miR-577, miR-874, and others) were found silenced in drug-resistant CRCs. Re-expression of tumor suppressor miR is complicated by the chemical nature of miRs that are not long-lasting compounds and require protection from the enzymatic degradation. Several recent studies explored application of miRs using nanocarrier complexes. This study critically describes the most successfully tested nanoparticle complexes used for intracellular delivery of nuclear acids and miRs, including micelles, liposomes, inorganic and polymeric NPs, dendrimers, and aptamers. Nanocarriers shield incorporated miRs and improve the agent stability in circulation. Attachment of antibodies and/or specific peptide or ligands facilitates cell-targeted miR delivery. Addressing in vivo challenges, a broad spectrum of non-toxic materials has been tested and indicated reliable advantages of lipid-based (lipoplexes) and polymer-based liposomes. Recent cutting-edge developments indicated that lipid-based complexes with multiple cargo, including several miRs, are the most effective approach to eradicate drug-resistant tumors. Focusing on CRC-specific miRs, this review provides a guidance and insights towards the most promising direction to achieve dramatic reduction in tumor growth and metastasis using miR-nanocarrier complexes.

Role of integrins in the metastatic spread of high-grade serous ovarian cancer

PURPOSE

Integrins may be involved in the metastatic spread of high-grade serous ovarian cancer (HGSOC) which determines the therapeutical approach and prognosis. We investigated the integrin expression in primary tumor and metastases of advanced HGSOC.

METHODS

The expression of integrin α2, α4, α5, α6, and β1 was assessed by immunostaining in tumor samples of the ovary, omentum, and peritoneum of each patient. Differences in integrin expression among tumor localizations and their association with clinicopathological parameters were examined by Fisher's exact test. The impact of integrin expression on progression-free survival (PFS) and overall survival (OS) was examined by Cox regression and Kaplan-Meier analyses.

RESULTS

Hundred and thirteen tumor samples of 40 HGSOC patients were examined. The expression of the integrins did not differ between the three tumor localizations (all p values > 0.05) with the exception of high expression of integrin α4 in primary tumor and omentum (52.5% versus 47.5%, p = 0.008) and primary tumor and peritoneum (52.5% versus 47.5%, p = 0.050). High expression of integrin α4 in peritoneum was associated with poorer PFS (HR 2.02 95% CI 1.01-4.05, p = 0.047), younger age (p = 0.047), and death (p = 0.046). Median PFS in patients with high expression of integrin α4 was 13.00 months, whereas median PFS in patients without high expression of integrin α4 was 21.00 months (p = 0.040). Expression of other integrins did not correlate with PFS or OS.

CONCLUSION

Expression of integrin α4 may be altered during the metastatic spread of HGSOC and affect prognosis, whereas expression of integrin α2, α5, α6, and β1 did not reveal any prognostic value.

Integrin α2β1 Represents a Prognostic and Predictive Biomarker in Primary Ovarian Cancer

Currently, the same first-line chemotherapy is administered to almost all patients suffering from primary ovarian cancer. The high recurrence rate emphasizes the need for precise drug treatment in primary ovarian cancer. Being crucial in ovarian cancer progression and chemotherapeutic resistance, integrins became promising therapeutic targets. To evaluate its prognostic and predictive value, in the present study, the expression of integrin α2β1 was analyzed immunohistochemically and correlated with the survival data and other therapy-relevant biomarkers. The significant correlation of a high α2β1-expression with the estrogen receptor alpha (ERα; p = 0.035) and epithelial growth factor receptor (EGFR; p = 0.027) was observed. In addition, high α2β1-expression was significantly associated with a low number of tumor-infiltrating immune cells (CD3 intratumoral, p = 0.017; CD3 stromal, p = 0.035; PD-1 intratumoral, p = 0.002; PD-1 stromal, p = 0.049) and the lack of PD-L1 expression (p = 0.005). In Kaplan–Meier survival analysis, patients with a high expression of integrin α2β1 revealed a significant shorter progression-free survival (PFS, p = 0.035) and platinum-free interval (PFI, p = 0.034). In the multivariate Cox regression analysis, integrin α2β1 was confirmed as an independent prognostic factor for both PFS (p = 0.021) and PFI (p = 0.020). Dual expression of integrin α2β1 and the hepatocyte growth factor receptor (HGFR; PFS/PFI, p = 0.004) and CD44v6 (PFS, p = 0.000; PFI, p = 0.001; overall survival [OS], p = 0.025) impaired survival. Integrin α2β1 was established as a prognostic and predictive marker in primary ovarian cancer with the potential to stratify patients for chemotherapy and immunotherapy, and to design new targeted treatment strategies.

DMBT1 suppresses cell proliferation, migration and invasion in ovarian cancer and enhances sensitivity to cisplatin through galectin-3/PI3k/Akt pathway

Ovarian cancer (OC) is one of the most common gynaecologic malignancies. Deleted in malignant brain tumors 1 (DMBT1) was considered as a tumour suppressor in multiple cancers, but there have been no systemic profiling studies of DMBT1 in OC until now. The aim of this study is to explore the role and the potential mechanism of DMBT1 in OC. mRNA levels and protein expressions of corresponding genes were detected by quantitative real-time polymerase chain reaction and western blot. Cell proliferation was detected by CCK-8 assay and cell colony formation. Cell migration and invasion were detected by wound healing and transwell assay. The combination between DMBT1 and galectin-3 was demonstrated by immunoprecipitation. We demonstrated that DMBT1 was downregulated in OC cell lines, especially SKOV3 cells. Overexpression of DMBT1 significantly inhibited cell proliferation, colony formation, migration and invasion, as well as decreased Matrix Metalloproteinase-2 (MMP-2) and MMP-7. DMBT1 caused a reduction of cell viability by treatment with cisplatin. Immunoprecipitation assay revealed a combination between DMBT1 and galectin-3. DMBT1 could decrease the expression of galectin-3 and inhibit the phosphorylation of PI3K and AKT, while overexpression of galectin-3 reversed this effect. In summary, DMBT1 might inhibit the progression of OC and improve the sensitivity of SKOV3 cells to cisplatin through galectin-3/PI3K/AKT pathway, giving a new insight into the role of DMBT1 in OC and enriching the potential strategies for OC treatment. SIGNIFICANCE OF THE STUDY: The present study focus on the role and the potential mechanism of DMBT1 in ovarian cancer (OC). We demonstrated that DMBT1 might inhibit the progression of ovarian by inhibiting cell proliferation, migration and invasion and increased the sensitivity to cisplatin through galectin-3/PI3K/AKT pathway. The findings ensure the interaction relation between DMBT1 and galectin-3 in OC, providing a novel biological marker for OC and enriching the potential strategies for OC treatment.