Increased Nuclear Factor-κB/RelA Expression Levels in Human Colorectal Carcinoma in North Indian Patients

IL-1β enhances cell viability and decreases 5-FU sensitivity in novel colon cancer cell lines derived from African American patients

Background

In the U.S., African Americans (AAs) present with the highest incidence and mortality rates for Colorectal Cancer (CRC). When compared to Caucasian American (CA) patients, AAs also have reduced response to the first line standard of care chemotherapeutic agent 5-Fluorouracil (5-FU). Previously, we observed differential gene expression between the two populations, suggesting that colon tumors from AA patients display a decreased antitumor immune response and an increased expression of genes encoding proteins involved in inflammatory processes, such as Interleukin-1β (IL-1β). Here, we investigate the role of IL-1β in modifying chemotherapeutic response and altering expression of proteins in novel AA and well-established CA colon cancer cell lines.

Methods

RNA sequencing analysis was performed to detect expression of genes involved in inflammation in AA and CA colon cancer cells. The effects of IL-1β on 5-FU response was evaluated by assessing cell viability (MTS assay) and apoptosis (flow cytometry analysis) following treatment with 5-FU alone or in combination with the cytokine. Further, we used an IL-1 receptor antagonist (IL-1Ra) to inhibit IL-1β-induced effects on 5-FU sensitivity and NF-kB pathway activation.

Results

AA colon cancer cell lines present significant increase in expression of genes IL1R2 (373-fold change (FC), IRAK1 (3.24 FC), IKBKB, (5.33 FC) NF-KB IA (5.95 FC), MYD88, (3.72 FC), IRAK3 (161 FC), TRAF5 (4.1 FC). A significant decrease in the response to 5-FU treatment, as well as a significant increase in phosphorylation of IκBα and secretion of IL-8, was seen following IL-1β treatment, in both AA and CA cell lines. Finally, treatment with IL-1Ra was able to reverse the effects induced by IL-1β, by increasing the cells sensitivity to 5-FU. IL-1Ra also inhibited phosphorylation of IκBα and IL-8 secretion.

Conclusions

Our results suggest a differential expression of inflammatory genes and proteins that might regulate the different response to IL-1β between AA and CA colon cancer cell lines. Our data also demonstrates that IL-1β is involved in modulating 5-FU response in both AA and CA colon cancer cell lines. Further investigation of these mechanisms might help elucidate the differences seen in incidence, mortality and response to therapy in AA colon cancer patients.

From inflammatory bowel disease to colorectal cancer: what's the role of miRNAs?

Inflammatory Bowel Disease (IBD) is a chronic inflammatory disease with relapse and remission periods. Ulcerative colitis and Crohn's disease are two major forms of the disease. IBD imposes a lot of sufferings on the patient and has many consequences; however, the most important is the increased risk of colorectal cancer, especially in patients with Ulcerative colitis. This risk is increased with increasing the duration of disease, thus preventing the progression of IBD to cancer is very important. Therefore, it is necessary to know the details of events contributed to the progression of IBD to cancer. In recent years, the importance of miRNAs as small molecules with 20-22 nucleotides has been recognized in pathophysiology of many diseases, in which IBD and colorectal cancer have not been excluded. As a result, the effectiveness of these small molecules as therapeutic target is hopefully confirmed. This paper has reviewed the related studies and findings about the role of miRNAs in the course of events that promote the progression of IBD to colorectal carcinoma, as well as a review about the effectiveness of some of these miRNAs as therapeutic targets.

The Phytochemical Profile and Biological Activity of Liquidambar orientalis Mill. var. orientalis via NF-κB and Apoptotic Pathways in Human Colorectal Cancer

Liquidambar orientalis Mill. var. orientalis (Hammamelidaceae) commonly known as oriental sweet gum is a medicinal plant endemic to Turkey, and used for treatment of wounds such as ulcers, gastritis and skin diseases. However, there are only a limited number of studies on the anticancer properties of this plant. The aim of this study is to investigate the cellular and molecular mechanisms of L. orientalis in colorectal cancer cell lines and to reveal the active therapeutic components. Antioxidant, anti-proliferative, anti-invasive and apoptotic effects were investigated for determining biological activities. The phytochemical profile and quantitation assays were carried out by using HPLC-ESI-Q-TOF-MS. The results demonstrated that leaf methanol extract (LM) of L. orientalis has the highest cytotoxic activity in HCT-116 (IC₅₀ 27.80 μg/mL) and HT-29 (IC₅₀ 43.13 μg/mL) cell lines as compared to the other extracts tested. Regarding chemical composition, quercetin 3-glucoside (61.005 ± 1.527 mg/g extract), chlorogenic acid (31.627 ± 0.970 mg/g extract), pyrogallol (9.950 ± 0.001 mg/g extract), epigallocatechin gallate (9.671 ± 0.004 mg/g extract), apigenin 7-O-glucoside (2.687 ± 0.027 mg/g extract), gallic acid (2.137 ± 0.012 mg/g extract), genistin (1.270 ± 0.027 mg/g extract), luteolin (0.055 ± 0.0005 mg/g extract) and kaempferol (0.506 ± 0.007 mg/g extract) were identified as the major phytochemical compounds. Our results showed that LM extract exhibited In Vitro cytotoxic and apoptotic properties.

Clinicopathological significance and prognostic implication of nuclear factor-κB activation in colorectal cancer

OBJECTIVE

The aim of the present study was to evaluate the clinicopathological significance of phosphorylated nuclear factor-κB (pNF-κB) expression, and its impact on epithelial-mesenchymal transition and angiogenesis in colorectal cancer (CRC).

METHODS

We carried out immunohistochemistry of pNF-κB on 261 human CRC tissues, and evaluated nuclear expression, regardless of cytoplasmic expression. We also investigated the correlation between pNF-κB expression and clinicopathological characteristics, survival, and epithelial-mesenchymal transition and angiogenesis-related markers in CRC.

RESULTS

pNF-κB was expressed in the nuclei of 164 of the 261 CRC tissues (62.8%). Furthermore, pNF-κB was significantly correlated with frequent perineural invasion, lymph node metastasis, and higher pTNM stage. However, there was no significant correlation between pNF-κB expression and other clinicopathological parameters. Among the epithelial-mesenchymal transition markers examined, SNAIL expression was significantly correlated with pNF-κB expression (P =  0.001) but E-cadherin expression was not. CRC with pNF-κB expression had significantly higher SIRT1 expression levels and hypoxia-inducible factor-1α expression levels than CRC without pNF-κB expression (P <  0.001 and P <  0.001, respectively). However, there was no correlation between the expression levels of pNF-κB and VEGF. pNF-κB expression was significantly correlated with worse overall and recurrence-free survival rates (P <  0.001 and P <  0.001, respectively).

CONCLUSION

pNF-κB expression was significantly correlated with aggressive tumor behaviors and worse survival rates. Furthermore, pNF-κB expression may affect tumor invasion and progression through SNAIL-related epithelial-mesenchymal transition and SIRT1- and hypoxia-inducible factor-1α-induced angiogenesis.

Over-Expression of Cyclooxygenase-2 in Colorectal Cancer Patients

Background:

Colorectal carcinoma (CRC) is the most common neoplasm of the gastrointestinal tract. COX-2 plays an important role in CRC development and is a key target for the regression of colorectal tumorigenesis by non-steroidal anti-inflammatory drugs. The present study was conducted to examine the relationship of the levels of COX-2 in CRC patients with the clinico-pathological parameters and also to assess its usefulness as a potential biomarker for diagnosis of CRC.

Methods:

Prior to surgery, 30 CRC patients were enrolled and the samples from colon tumors and surrounding tissues were taken after they underwent surgical intervention at PGIMER, Chandigarh. mRNA expression levels of COX-2 were examined in 30 CRC and adjacent normal colonic mucosa by quantitative polymerase chain reaction (qPCR). The expression of COX-2 was assessed by immunohistochemical method using rabbit polyclonal antibodies against human COX-2 protein.

Results:

The quantitative relative expression of COX-2 mRNA was observed to be significantly higher (p<0.05) in colorectal cancer tissues as compared to adjacent normal colon tissues. Also, female CRC patients showed significantly higher (p<0.009) expression of COX-2 mRNA vis-a-vis male colorectal cancer patients. This is the first study which has reported a direct relationship between COX-2 mRNA expressions in male colorectal cancer patients versus females. Further, immunohistochemistry of COX-2 confirmed the quantitative real time-PCR findings.

Conclusion:

Our study shows that COX-2 over expression in colorectal carcinoma patients is closely associated with clinico-pathological parameters and is more pronounced in males versus females. Further, COX-2 mRNA expression can serve as a potential biomarker for the diagnosis of CRC.