Impact of granulocyte colony-stimulating factors in metastatic colorectal cancer patients

G-CSF in tumors: Aggressiveness, tumor microenvironment and immune cell regulation

Granulocyte colony-stimulating factor (G-CSF) is a cytokine most well-known for maturation and mobilization of bone marrow neutrophils. Although it is used therapeutically to treat chemotherapy induced neutropenia, it is also highly expressed in some tumors. Case reports suggest that tumors expressing high levels of G-CSF are aggressive, more difficult to treat, and present with poor prognosis and high mortality rates. Research on this topic suggests that G-CSF has tumor-promoting effects on both tumor cells and the tumor microenvironment. G-CSF has a direct effect on tumor cells to promote tumor stem cell longevity and overall tumor cell proliferation and migration. Additionally, it may promote pro-tumorigenic immune cell phenotypes such as M2 macrophages, myeloid-derived suppressor cells, and regulatory T cells. Overall, the literature suggests a plethora of pro-tumorigenic activity that should be balanced with the therapeutic use. In this review, we present an overview of the multiple complex roles of G-CSF and G-CSFR in tumors and their microenvironment and discuss how clinical advances and strategies may open new therapeutic avenues.

The Highly Metastatic Nature of Uterine Cervical/Endometrial Cancer Displaying Tumor-Related Leukocytosis: Clinical and Preclinical Investigations

Purpose: The aim of this study was to investigate the metastatic potential of uterine cervical and endometrial cancer displaying tumor-related leukocytosis (TRL).Experimental Design: Clinical data on uterine cervical (N = 732) and endometrial cancer (N = 900) were collected, and the metastatic potential of TRL-positive cancer was evaluated in univariate and multivariate analyses. Tumor and blood samples obtained from patients with cervical cancer, cervical cancer cell lines, and a mouse model of cervical cancer were used to examine the mechanisms underlying the highly metastatic nature of TRL-positive cancer, focusing on tumor-derived G-CSF and the myeloid-derived suppressor cell (MDSC)-mediated premetastatic niche.Results: Pretreatment TRL was significantly associated with visceral organ metastasis in patients with uterine cervical or endometrial cancer. The patients with TRL-positive cervical cancer displayed upregulated tumor G-CSF expression, elevated G-CSF levels, and increased MDSC frequencies in the peripheral blood compared with the TRL-negative patients. In vitro and in vivo investigations revealed that MDSCs produced in response to tumor-derived G-CSF are involved in premetastatic niche formation, which promotes visceral organ metastasis of TRL-positive cancer. The depletion of MDSCs attenuated this premetastatic niche formation and effectively inhibited the visceral organ metastasis of TRL-positive cancer.Conclusions: Uterine cervical/endometrial cancer displaying TRL is a distinct clinical entity with high metastatic potential. Tumor-derived G-CSF and the MDSC-mediated premetastatic niche are responsible for the highly metastatic nature of this type of cancer. MDSC-targeting therapy might represent a potential strategy for combating metastasis derived from TRL-positive uterine cancer. Clin Cancer Res; 24(16); 4018-29. ©2018 AACR.

Relative rates not relative risks: addressing a widespread misinterpretation of hazard ratios

The use of the Cox proportional hazards model is ubiquitous in modern medical research. Despite the widespread implementation of this model, the terminology and interpretation that is used to describe the estimate hazard ratio (HR) has become loose and, unfortunately, often incorrect. Although some journals offer guidelines that advise against reporting HRs as relative risks, these guidelines are frequently overlooked. Perhaps due to a lack of understanding, authors continue to interpret the resultant HR as a relative risk-such an interpretation is inappropriate and can be misleading. The HR should be described as a relative rate, not as a relative risk. This article demonstrates that although the direction of the HR can be used to explain the direction of the relative risk, the magnitude of the HR alone cannot be used to explain the magnitude of the relative risk. This article clarifies the relationship between HRs and relative risks in a way that may be better suited for the applied clinical researcher. We also provide a convenient table illustrating the magnitude of relative risk under various values of the HR; the table demonstrates that for a given constant HR, the magnitude of the relative risk can vary substantially. As a take-home message, authors should refrain from using the magnitude of the HR to describe the magnitude of the relative risk. Authors should be strongly encouraged to ascribe accurate interpretations to the statistics derived from fitted Cox proportional hazards regression models.

Increased FSHD region gene1 expression reduces in vitro cell migration, invasion, and angiogenesis, ex vivo supported by reduced expression in tumors

Facioscapulohumeral muscular dystrophy (FSHD) region gene 1 (FRG1) is a candidate gene for FSHD. FRG1 regulates various muscle-related functions, but studies have proposed its role in development and angiogenesis also, where it is involved with tumor-associated molecules. Therefore, we decided to look into its role in tumor progression, tumor angiogenesis, and its impact on cellular properties. Cell proliferation, migration, invasion and in vitro angiogenesis assays were performed to decipher the effect of FRG1 on endothelial and epithelial cell functions. Q-RT PCR was done for human embyonic kidney (HEK293T) cells with altered FRG1 levels to identify associated molecules. Further, immunohistochemistry was done to identify FRG1 expression levels in various cancers and its association with tumor angiogenesis. Subsequently, inference was drawn from Oncomine and Kaplan-Meier plotter analysis, for FRG1 expression in different cancers. Ectopic expression of FRG1 affected cell migration and invasion in both HEK293T and human umbilical vein endothelial cells (HUVECs). In HUVECs, FRG1 overexpression led to reduced angiogenesis in vitro No effect was observed in cell proliferation in both the cell types. Q-RT PCR data revealed reduction in granulocyte-colony stimulating factor (G-CSF) expression with FRG1 overexpression and increased expression of matrix metalloproteinase 10 (MMP10) with FRG1 knockdown. Immunohistochemistry analysis showed reduced FRG1 levels in tumors which were supported by in silico analysis data. These findings suggest that reduction in FRG1 expression in gastric, colon and oral cavity tumor might have a role in tumor progression, by regulating cell migration and invasiveness. To elucidate a better understanding of molecular signaling involving FRG1 in angiogenesis regulation, further study is required.