Lung cancer has the highest mortality rate among human cancers, and the majority of deaths can be attributed to metastatic spread. Lung cancer stem cells (CSCs) are a component of the tumour microenvironment that contributes to this process. Exosomes are small membrane vesicles secreted by all types of cells that mediate cell interactions, including cancer metastasis. Here, we show that lung CSC‐derived exosomes promote the migration and invasion of lung cancer cells, up‐regulate expression levels of N‐cadherin, vimentin, MMP‐9 and MMP‐1, and down‐regulate E‐cadherin expression. Moreover, we verified that these exosomes contribute to a pro‐metastatic phenotype in lung cancer cells via miR‐210‐3p transfer. The results of bioinformatics analysis and dual‐luciferase reporter assays further indicated that miR‐210‐3p may bind to fibroblast growth factor receptor‐like 1 (FGFRL1); silencing FGFRL1 enhanced the metastatic ability of lung cancer cells, whereas overexpressing FGFRL1 suppressed metastasis. Taken together, our results provide new insights into a potential molecular mechanism whereby lung CSC‐derived exosomal miR‐210‐3p targets FGFRL1 to promote lung cancer metastasis. FGFRL1 may be a promising therapeutic target in lung cancer.

The development of cancer immunotherapy, particularly immune checkpoint blockade therapy, has made major breakthroughs in the therapy of cancers. However, less than one-third of the cancer patients obtain significant and long-lasting therapeutic effects by cancer immunotherapy. Over the past few decades, cancer-related inflammations have been gradually more familiar to us. It’s known that chronic inflammation in tumor microenvironment (TME) plays a predominant role in tumor immunosuppression. Tumor-associated extracellular matrix (ECM), as a core member of TME, has been a research hotspot recently. A growing number of studies indicate that tumor-associated ECM is one of the major obstacles to realizing more successful cases of cancer immunotherapy. In this review, we discussed the potential application of tumor-associated ECM in the cancer immunity and its aide potentialities to anti-tumor immunotherapy.

Over the years, there has been a high demand for developing new safe and effective drug carriers for cancer therapy. Emerging studies have indicated that exosomes can serve as potent therapeutic carriers since they offer low immunogenicity, high stability, innate and acquired targetability, and the stimulation of anti-cancer immune responses. Yet, the development of exosome-based drug delivery systems remains challenging due to their heterogeneity, low yield, and limited drug loading efficiency. Herein, we summarized the current application of exosomes derived from different cells as drug carriers in anti-cancer therapy in vitro and in vivo. We also discussed the challenges and prospects of exosome-based drug delivery systems in cancer therapy.

Zoledronic acid is the most potent osteoclast inhibitor and is widely used for advanced cancer patients with bone metastasis, but its role on cancer stem cells (CSCs) remains unclear. In the present study, we aimed to identify the stemness phenotypic characteristics of CSCs derived from cervical cancer cells and explore the anti-cancer efficiency of zoledronic acid on these cells, as well as the possible molecular mechanisms. Stemness phenotypic identification of cervical cancer cells derived CSCs was performed via sphere formation efficiency (SFE), tumorigenesis, immunofluorescence staining, Transwell assay, and western blot. Anti-cancer efficiency of zoledronic acid on these cells (including proliferation, stemness phenotype, apoptosis, and cell cycle) was carried out through MTT assay, SFE, transwell, DAPI staining, flow cytometry, immunofluorescence, TUNEL staining, and western blot, both in vitro and in vivo. Enhanced self-renewal ability, including SFE and tumorigenesis, was verified in cervical cancer cells derived CSCs compared to parental cervical cancer cells. Specifically, the expression of ALDH1, Sox2, CD49f, Nanog, and Oct4 was significantly up-regulated in cervical cancer cells derived CSCs. Furthermore, enhanced migratory ability was observed in these cells along with up-regulated N-cadherin and Vimentin and down-regulated E-cadherin. Zoledronic acid inhibited cervical cancer cells derived CSCs proliferation in vitro and in vivo. The stemness phenotype of these CSCs including tumor sphere formation, migration, as well as the expression of the aforementioned associated markers was also suppressed. In addition, zoledronic acid significantly induced apoptosis and cell cycle arrest of cervical cancer cells derived CSCs in a dose-dependent manner. Mechanistically, the expression of phosphorylated Erk1/2 and Akt was significantly increased in cervical cancer cells derived CSCs compared to parental cervical cancer cells. Zoledronic acid inhibited phosphorylated Erk1/2 and Akt in cervical cancer cells derived CSCs. IGF-1, a potent stimulator for Erk1/2 and PI3K/Akt, attenuated the aforementioned anti-cancer effect of zoledronic acid. Zoledronic acid inhibited the growth of cervical cancer cells derived CSCs through attenuating their stemness phenotype, inducing apoptosis, and arresting cell cycle. The suppression of phosphorylated Erk1/2 and Akt was involved in this process.

Matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9 (MMP-9) are critical components of the extracellular matrix (ECM) in colorectal cancer (CRC). We aimed to evaluate the prognostic value of MMP-2 and MMP-9 in patients with CRC. We performed a meta-analysis of cohort studies with available data on the effect of MMP-2 and MMP-9 expression on both disease-free survival (DFS) and overall survival (OS) by the risk ratios (RRs) with their 95% confidence intervals (CIs). Studies were subgrouped based on the different tissue types, including cancer tissue and normal tissue, and the subgroup effect of MMP expression in different tissues was analyzed through meta-regression. To ensure the quality and reduce the risk of bias, the Newcastle‒Ottawa Scale (NOS) was used to assess the included studies. A sensitivity analysis was randomly performed to assess the potential impact of each study on our results. Eighteen trials were selected (Table 1) and included a total of 3944 patients. According to our primary meta-analysis, the expression of MMP-2 was significantly associated with a decrease in OS (RR = 1.75, 95% CI = 1.34 to 2.29, P < 0.001) and DFS (RR = 2.62, 95% CI = 1.25 to 5.49, P < 0.001), and the expression of MMP-9 was not significantly associated with a decrease in OS (RR = 1.48, 95% CI = 0.97 to 2.24, P = 0.069) or DFS (RR = 1.60, 95% CI = 0.87 to 2.94, P = 0.133). According to the subgroup analysis of MMPs in different tissues, high MMP-2 expression in cancer tissue (RR = 1.90, 95% CI = 1.29 to 2.79) and normal tissue (RR = 1.59, 95% CI = 1.17 to 2.17) were significant indicators of poor OS. High MMP-2 expression in cancer tissue was significant indicator of poor DFS (RR = 2.12, 95% CI = 1.09 to 4.11). MMP-9 expression was also associated with poor OS (RR = 1.40, 95% CI = 0.85 to 2.29), but the difference in OS between the high and low expression groups was not statistically significant. High MMP-2 expression, especially in cancer tissue, is significantly associated with both poor DFS and poor OS in patients with CRC. High MMP-9 expression tended to indicate a poor prognosis of CRC but the correlation was not significant.