An update to experimental and clinical aspects of tumor-associated macrophages in cancer development: hopes and pitfalls.

Tumor-associated macrophages (TAMs) represent one of the most abundant tumor-infiltrating stromal cells, and their normal function in tumor microenvironment (TME) is to suppress tumor cells by producing cytokines which trigger both direct cell cytotoxicity and antibody-mediated immune response. However, upon prolonged exposure to TME, the classical function of these so-called M1-type TAMs can be converted to another type, "M2-type," which are recruited by tumor cells so that they promote tumor growth and metastasis. This is the reason why the accumulation of TAMs in TME is correlated with poor prognosis in cancer patients. Both M1- and M2-types have high degree of plasticity, and M2-type cells can be reprogrammed to M1-type for therapeutic purposes. This characteristic introduces TAMs as promising target for developing novel cancer treatments. In addition, inhibition of M2-type cells and blocking their recruitment in TME, as well as their depletion by inducing apoptosis, are other approaches for effective immunotherapy of cancer. In this review, we summarize the potential of TAMs to be targeted for cancer immunotherapy and provide an up-to-date about novel strategies for targeting TAMs.

While Urine and Plasma Decorin Remain Unchanged in Prostate Cancer, Prostatic Tissue Decorin Has a Prognostic Value.

Background: Numerous studies confirmed that significant decrease in tissue decorin (DCN) expression is associated to tumor progression and metastasis in certain types of cancer including prostate cancer (PC). However, the potential prognostic value of tissue DCN in PC has not yet been investigated. Methods: A total number of 40 PC and 42 patients with benign prostatic hyperplasia (BPH) were investigated for the expression levels of DCN in their prostatic tissues using real-time quantitative polymerase chain reaction and immunohistochemical analyses. Urinary and plasma DCN levels were also measured by ELISA. Results: Despite no significant changes in the mean of urine and plasma DCN concentrations between the two study groups, tissue DCN mRNA was found to be 5.5fold lower in cancer than BPH (p = 0.0001). Similarly, the stained DCN levels appeared significantly lower in cancer patients with higher Gleason Scores (8 and 9, n = 6) than those with lower Gleason Scores (6 and 7, n = 26), with a p value of 0.049. Conclusion: Here, we report, for the first time, that urine and plasma DCN does not seem to have a diagnostic value in PC, while tissue DCN could potentially be used as a prognostic marker in PC.

Patients With Invasive Ductal Carcinoma Have Reduced Levels of Decorin Expression in Their Breast Tissue Compared to Patients With Fibroadenoma While Plasma Decorin Remains Unchanged.

BACKGROUND: Reduction in the level of tissue decorin is a hallmark of many types of cancer including breast carcinoma. However, reduced decorin expression has also been reported in several types of benign tumors to the extent that it has been proposed as a tissue marker to differentiate malignant from benign tumors. The aim of this study was to investigate the potential role of plasma decorin to distinguish breast cancer from fibroadenoma, the second most common type of benign tumor, after fibrocystic disease. METHODS: From 35 patients recruited in this study, 24 were affected with invasive ductal carcinoma, either grade II (n = 14) or grade III (n = 10). The other 11 patients had fibroadenoma lesions in their breasts. Tissue decorin mRNA and protein levels were assessed with real-time qPCR and Immunohistochemical analysis. ELISA was employed to measure plasma levels of decorin. RESULTS: The mean plasma decorin in cancer patients was measured to be 5.42 ± 1.83 ng/mL while fibroadenoma patients had an average of 4.22 ± 1.17 ng/mL decorin in their plasma. The difference was not significant. However, the mean expression level of decorin mRNA calculated by the 2-ΔΔCt method was 5.6-fold lower in the biopsied tissue specimens of IDC patients versus fibroadenoma, as expected. Consistent reduction in protein abundance was observed in the studied tissue sections. CONCLUSION: We have shown that tissue decorin is a reliable marker, unaffected by patient disease stage, to differentiate IDC from fibroadenoma. However, plasma decorin does not seem to have diagnostic value in this regard.