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Expression of monocyte chemoattractant protein-1 (MCP-1) and CC chemokine receptor 2 (CCR2) and its significance has been demonstrated in some cancer cells in recent clinical studies. However, the role of tumor MCP-1 and CCR2 expression in non-small cell lung cancer (NSCLC) remains unknown. The aim of the present study was to investigate the prognostic significance of MCP-1 and CCR2 expression in NSCLC cells. The relationship between MCP-1 and CCR2 expression in NSCLC cancer cells was examined by immunohistochemical staining of surgical specimens from 134 patients. Sixty-five of these patients had follow-up records. Kaplan-Meier analysis and Cox regression model were used to assess overall survival according to the presence or absence of MCP-1 and CCR2 expression in tumor cells. MCP-1 was detected in cancer cells of 107 NSCLC (79.9 %) and CCR2 was detected in cancer cells of 39 NSCLC (29.1 %). MCP-1 expression was correlated with sex, smoking habits, histology, and tumor size. Presence of MCP-1 in tumor cells was associated with better overall survival ( P = 0.018). By multivariate analysis, MCP-1 expression in cancer cells showed an independent prognostic factor for overall survival ( P = 0.002, hazard ratio [HR] = 0.256, 95 % confidence interval [CI] = 0.106-0.616). There was no significant relationship between CCR2 expression in tumor cells and clinical and pathological characteristics. Also, no significant positive correlation between MCP-1 and CCR2 expression was revealed by Spearman correlation analysis. Our data indicate that MCP-1 is overexpressed in NSCLC cells. Its expression in cancer cells is associated with better survival in NSCLC patients. [ABSTRACT FROM AUTHOR]

Targeting replication stress response is currently emerging as new therapeutic strategy for cancer treatment, based on monotherapy and combination approaches. As a key sensor in response to DNA damage, ataxia telangiectasia and rad3-related (ATR) kinase has become a potential therapeutic target as tumor cells are to rely heavily on ATR for survival. The tumor suppressor phosphatase and tensin homolog (PTEN) plays a crucial role in maintaining chromosome integrity. Although ATR inhibition was recently confirmed to show a synergistic inhibitory effect in PTEN-deficient triple-negative breast cancer cells, the molecular mechanism needs to be further elucidated. Additionally, whether the PTEN-deficient breast cancer cells are more preferentially sensitized than PTEN-wild type breast cancer cells to cisplatin plus ATR inhibitor remains unanswered. We demonstrate PTEN dysfunction promotes the killing effect of ATR blockade through the use of RNA interference for PTEN and a highly selective ATR inhibitor VE-821, and certify that VE-821 (1.0 μmol/L) aggravates cytotoxicity of cisplatin on breast cancer cells, especially PTEN-null MDA-MB-468 cells which show more chemoresistance than PTEN-expressing MDA-MB-231 cells. The co-treatment with VE-821 and cisplatin significantly reduced cell viability and proliferative capacity compared with cisplatin mono-treatment (P < 0.05). The increased cytotoxic activity is tied to the enhanced poly (ADP-ribose) polymerase (PARP) cleavage and consequently cell death due to the decrease in phosphorylation levels of checkpoint kinases 1 and 2 (CHK1/2), the reduction of radiation sensitive 51 (RAD51) foci and the increase in phosphorylation of the histone variant H2AX (γ-H2AX) foci (P < 0.05) as well. Together, these findings suggest combination therapy of ATR inhibitor and cisplatin may offer a potential therapeutic strategy for breast tumors. • ATR inhibition significantly enhances cytotoxicity effect of cisplatin on PTEN-deficient breast cancer cells. • ATR inhibition reinforces the accumulation of cisplatin-induced DNA damage. • ATR inhibition potentiates cisplatin-induced genotoxic stress by disturbing HR-mediated DNA repair. [ABSTRACT FROM AUTHOR]