Effect of CXCR4 and CD133 co-expression on the prognosis of patients with stage II~III colon cancer

CXCR4 knockdown enhances sensitivity of paclitaxel via the PI3K/Akt/mTOR pathway in ovarian carcinoma

Epithelial ovarian cancer (EOC) is the deadliest gynecological malignancy. EOC control remains difficult, and EOC patients show poor prognosis regarding metastasis and chemotherapy resistance. The aim of this study was to estimate the effect of CXCR4 knockdown-mediated reduction of cancer stem cells (CSCs) and epithelial-mesenchymal transition (EMT) stemness and enhancement of chemotherapy sensitivity in EOC. Mechanisms contributing to these effects were also explored. Our data showed distinct contribution of CXCR4 overexpression by dependent PI3K/Akt/mTOR signaling pathway in EOC development. CXCR4 knockdown resulted in a reduction in CSCs and EMT formation and enhancement of chemotherapy sensitivity in tumor cells, which was further advanced by blocking CXCR4-PI3K/Akt/mTOR signaling. This study also documented the critical role of silencing CXCR4 in sensitizing ovarian CSCs to chemotherapy. Thus, targeting CXCR4 to suppress EOC progression, specifically in combination with paclitaxel (PTX) treatment, may have clinical application value.

Clinical Significance of Cancer Stem Cell Markers CD133 and CXCR4 in Osteosarcomas

Objective:

Osteosarcomas (OS) is one the most common primary bone malignancy in humans with the lungs metastasis in most cases. Metastasis and recurrence of OS is attributed to cancer stem cells (CSCs). Our study aimed to evaluate the clinical significance of CD133 and C-X-C chemokine receptor type 4 (CXCR4) as the frequently applied markers for CSCs in OS patients.

Methods:

In this cross-sectional, a total of 50 tissue samples from the patients with primary OS were immunohistochemically examined to detect the expression of CD133 and CXCR4. The associations of the relative expression and clinical significance of each marker were also evaluated.

Results:

High level expression of CD133 was detected in 26% of OS patient tissues. Of the 12 patients who showed lung metastasis, 5 cases showed high expression of CD133 with marginal trend correlation (P=0.06). No significant correlation was observed between CD133 expression and clinicopathological factors. Only 36% of cases showed CXCR4 expression which was not significantly correlated with gender, age, tumor size, necrosis, stage and metastasis (P>0.05). Clinically, patients with concomitant CD133/CXCR4 expression had significant association with lung metastasis (P=0.05).

Conclusion:

Our findings showed that concomitant expression of CSC markers CD133/CXCR4 might had a synergistic effect on the OS poor prognosis. These markers could be considered as potential therapeutic candidates of OS targeted therapy.

CD133 expression correlates with clinicopathologic features and poor prognosis of colorectal cancer patients: An updated meta-analysis of 37 studies

BACKGROUND

CD133 has been identified as a putative cancer stem cell marker in colorectal cancer (CRC). However, the clinicopathological and prognostic significance of CD133 in CRC patients remains controversial. Thus, we conducted a meta-analysis to quantitatively evaluate the above issues.

METHODS

We collected a comprehensive literature search from PubMed, Web of Science, and Embase database up to September 20, 2016 examining CD133 and clinical features of colorectal cancer patients. We used the odds ratio (OR) with 95% confidence interval (CI) to estimate the effects by overall and stratified analysis.

RESULTS

The overall result of our meta-analysis indicated that CD133 expression was positively correlated with T category, distant metastasis, lymphatic invasion, and vascular invasion. Moreover, patients with higher CD133 expression had a poorer overall survival (OS) (HR=2.01, P < .001) and a lower 5-year OS rate (OR = 3.26, P < .001) than those with lower expression. Disease-free survival (DFS) and 5-year DFS rate were similar with the above results. Though the correlation between CD133 expression with the clinical characteristic was not positive in some ways when we analyzed the different subgroup. The prognostic value of CD133 expression for 5-year OS rate of CRC patients was noticeable in spite of different patients' region, multiple antibodies used in studies, various cut-off values of CD133 expression, and adjuvant therapy situation of patients.

CONCLUSION

CD133 is a useful predictive or prognostic biomarker for CRC in clinical assessment and may serve as a potential therapeutic target for CRC.

CXCR4 is involved in CD133-induced EMT in non-small cell lung cancer

Metastasis is the major cause of death in patients with non-small cell lung cancer (NSCLC), and epithelial-mesenchymal transition (EMT) has been observed to be one of the key regulators of metastasis in certain cancers as it confers an invasive phenotype. CD133 is a widely used cancer stem cell (CSC) marker, and CD133-positive cancer cells are thought to be tumor-initiating cells with CSC characteristics, while CXCR4, a stromal-derived-factor-1 specific chemokine receptor, is highly expressed in NSCLC tissues and participates in cancer progression by regulating cell anti-apoptosis. We previously demonstrated that CXCR4 promotes NSCLC chemoresistance by upregulating CYP1B1, however, the relationship of CD133, CXCR4 and EMT processes in NSCLC metastasis are unclear. In this study, we detected a CD133 and CXCR4 high expression in tissue specimens from 64 NSCLC patients by immunohistochemistry, of which CD133 and CXCR4 were found to be positively associated with metastatic NSCLC patients. CD133 was found to promote NSCLC tumorigenesis and mediated the expression of CXCR4. Furthermore, CD133/CXCR4 co-expression was found to be an independent prognostic factor as shown by univariate and multivariate Cox regression analysis, and was observed to regulate the expression of EMT-related molecules and transcriptional factors in NSCLC. In addition, our results showed that E-cadherin and Vimentin were simultaneously downregulated and upregulated, in CD133+CXCR4+ A549 cells, respectively. While E-cadherin was upregulated and Vimentin was downregulated in metastatic NSCLC patients. Vimentin expression was also observed to have a positive correlation with CD133/CXCR4 co-expression in NSCLC patients and survival analysis results suggested that Vimentin high expression might be significantly associated with poor survival rates of the patients. Thus, these results suggest that the CD133/CXCR4/EMT axis may be a prognostic marker and may provide novel targets for combinational therapies in the treatment of NSCLC.

The Effect of Analogues of 1α,25-Dihydroxyvitamin D₂ on the Regrowth and Gene Expression of Human Colon Cancer Cells Refractory to 5-Fluorouracil

This study aimed to evaluate the capacity of hypocalcemic analogues of 1α,25-dihydroxyvitamin D₂ (1,25D2) and 1α,25-dihydroxyvitamin D₃ (1,25D3) to inhibit regrowth and regulate the stemness-related gene expression in colon cancer cells undergoing renewal after exposure to 5-fluorouracil (5-FU). All of the tested analogues of 1,25D2 equally potently decreased the clonogenicity and the proliferative activity of HT-29 cells which survived the exposure to 5-FU, but differently regulated gene expression of these cells during their renewal. 1,25D2 and analogues (PRI-1907 and PRI-1917), as well as 1,25D3 and analogue PRI-2191, decreased the relative expression level of several stemness-related genes, such as NANOG, OCT3/4, PROM1, SOX2, ALDHA1, CXCR4, in HT-29/5-FU cells during their renewal, in comparison to untreated HT-29/5-FU cells. The other 1,25D2 analogues (PRI-1906 and PRI-1916) were not capable of downregulating the expression of these stemness-related genes as the analogues PRI-1907 and PRI-1917 did. All of the tested vitamin D analogues upregulated CDH1, the gene encoding E-cadherin associated with epithelial phenotype. Out of the series of analogues studied, side-chain branched analogues of 1,25D2 (PRI-1907, PRI-1917) and the analogue of 1,25D3 (PRI-2191) might be used to target cancer cells with stem-like phenotypes that survive conventional chemotherapy.