The EGFR R521K polymorphism influences the risk to develop colorectal cancer

Assessment of HER1 (rs11543848) and HER2 (rs1136201) polymorphism and their association with colorectal cancer susceptibility in Khyber Pakhtunkhwa, Pakistan

BACKGROUND

Colorectal cancer (CRC) is a widespread malignancy characterized by uncontrolled growth in the colon or rectum and remains a leading cause of cancer-related mortality globally. Various genes polymorphisms have been linked with the risk of CRC, but our study aimed to investigate the association between HER1 (rs11543848) and HER2 (rs1136201) polymorphisms with the risk of CRC in the Khyber Pakhtunkhwa (KPK) population of Pakistan. The association of the selected polymorphisms (rs11543848 and rs1136201) with CRC risk has been investigated in various ethnic groups, but their impact remains unexplored in Pakistan, particularly within the KPK population, highlighting the need of the study in this region.

METHODS

In this study 120 CRC patients and 120 healthy controls were enrolled. The DNA was extracted from the blood by salting-out method and genotyping was done using ARMS-PCR.

RESULTS

Our investigations provided convincing evidence of a strong association between HER1 (rs11543848) and the risk of CRC. Both the genotypes heterozygous GA (OR = 2.07, CI = 1.18 to 3.64, P = 0.01) and homozygous AA (OR = 6.22, CI = 2.56 to 15.08, P = 0.0001) showed higher risk and significant association with the CRC risk. Similarly, heterozygous genotype AG of HER2 (rs1136201) was significantly associated (OR = 3.16, 95% CI = 1.78 to 5.58, P = 0.0001) while mutant genotype GG showed higher risk but non-significant association (OR = 3.23, 95% CI = 0.84 to 12.43, P = 0.08) with CRC patients. HER1 (rs11543848) demonstrated a significant association (P = 0.003) with the age at diagnosis in CRC patients, while HER2 (rs1136201) showed a non-significant association (P = 0.434). Both the SNPs were non-significantly associated with gender (P = 0.793 and 0.117), metastasis (P = 0.582 and 0.129), location of the tumor (P = 0.555 and 0.993), tumor grade (P = 0.290 and 0.920), tumor size (P = 0.535 and 0.289) and stages of cancer (P = 0.892 and 0.352).

CONCLUSION

In conclusion, both the polymorphisms rs11543848 and rs1136201 displayed susceptibility with CRC in the KPK population. However, further investigations are recommended while using whole exome sequencing on a larger sample size for more precise results.

Genetic variants of the EGFR ligand-binding domain and their association with structural alterations in Arab cancer patients

Objective

This study aimed to identify novel genetic variants in the CR2 extracellular domain of the epidermal growth factor receptor (EGFR) in healthy individuals and patients with six different types of adenocarcinoma, in Arabian peninsula populations. It also aimed to investigate the effects of these variants on the EGFR structure and their eventual relevance to tumorigenesis.

Results

We detected seven new EGFR genetic variants in 168 cancer patients and 114 controls. A SNP rs374670788 was more frequent in bladder cancer but not significantly associated to. However, a missense mutation (V550M) was significantly associated to colon, ovary, lung, bladder and thyroid cancer samples (p < 0.05). Three mutations (H590R, E602K and T605T) were found in the heterozygous form only in colon cancer patients. Genomic analysis of the synonymous mutation (G632G) showed that the T/A genotype could be associated to thyroid cancer in Arab patients (p < 0.05). An additional novel SNP rs571064657 was observed in control individuals. Computational analysis of the genetic variants revealed a reduction in the stabilization of the EGFR tethered form for both V550M and the common R521K variant with low energetic state (− ∆∆G). Molecular interactions analysis suggested that these mutations might affect the receptor’s function and promote tumorigenesis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13104-021-05559-y.

Possible Gender-Related Modulation by the ROCK1 Gene in Colorectal Cancer Susceptibility

AIM

In view of accumulating evidence supporting a pivotal role of the Rho/ROCK pathway in cancer, we investigated Rho-kinase polymorphisms as potential susceptibility factors in colorectal cancer (CRC) in a representative sample of the Italian population.

METHODS

DNA obtained from the peripheral blood samples of 137 CRC patients and 141 healthy controls was genotyped for four ROCK1 (rs35996865; rs73963110; rs2127958; rs288980) and five ROCK2 (rs12692437; rs7563468; rs35768389; rs17463896; rs16857265) selected single nucleotide polymorphisms.

RESULTS

None of the allelic variants of the nine selected markers was associated with the occurrence of CRC or with the development of regional lymph node metastasis. By contrast, the ROCK1 rs35996865 G variant allele was significantly more frequent in male patients (p = 0.028) than in the control group.

CONCLUSION

This finding is, at present, the first that points to a possible gender-related modulation by the ROCK1 gene in CRC susceptibility.

Identification of epidermal growth factor receptor (EGFR) genetic variants that modify risk for head and neck squamous cell carcinoma

EGFR polymorphisms have not been thoroughly evaluated for association with head and neck squamous cell carcinoma (HNSCC) risk. We genotyped 578 HNSCC patients and 588 cancer-free controls for 60 EGFR single nucleotide polymorphisms (SNPs) and tested associations with HNSCC risk. EGFR intronic SNPs rs12535536, rs2075110, rs1253871, rs845561 and rs6970262 and synonymous SNP rs2072454 were associated with HNSCC risk among all subjects (p < 0.05). SNPs rs12538371, rs845561, and rs6970262 were significantly associated with HNSCC risk (p < 0.05) among never tobacco users. We identified EGFR variants that likely modify risk for HNSCC including three variants that contribute to tobacco-independent risk.

A Meta-Analysis on the Relations between EGFR R521K Polymorphism and Risk of Cancer

The EGFR R521K polymorphism has been shown to reduce the activity of EGFR; however, the association between EGFR R521K polymorphism and the risk of cancer remains inconclusive; therefore we performed a meta-analysis to evaluate the relationship between EGFR R521K polymorphism and susceptibility to cancer. Our results suggest that the EGFR R521K polymorphism is not associated with risk of cancer, but the different chemosensitivity to anticancer drugs may need further investigation.

The mitochondrial cardiolipin remodeling enzyme lysocardiolipin acyltransferase is a novel target in pulmonary fibrosis

RATIONALE

Lysocardiolipin acyltransferase (LYCAT), a cardiolipin-remodeling enzyme regulating the 18:2 linoleic acid pattern of mammalian mitochondrial cardiolipin, is necessary for maintaining normal mitochondrial function and vascular development. We hypothesized that modulation of LYCAT expression in lung epithelium regulates development of pulmonary fibrosis.

OBJECTIVES

To define a role for LYCAT in human and murine models of pulmonary fibrosis.

METHODS

We analyzed the correlation of LYCAT expression in peripheral blood mononuclear cells (PBMCs) with the outcomes of pulmonary functions and overall survival, and used the murine models to establish the role of LYCAT in fibrogenesis. We studied the LYCAT action on cardiolipin remodeling, mitochondrial reactive oxygen species generation, and apoptosis of alveolar epithelial cells under bleomycin challenge.

MEASUREMENTS AND MAIN RESULTS

LYCAT expression was significantly altered in PBMCs and lung tissues from patients with idiopathic pulmonary fibrosis (IPF), which was confirmed in two preclinical murine models of IPF, bleomycin- and radiation-induced pulmonary fibrosis. LYCAT mRNA expression in PBMCs directly and significantly correlated with carbon monoxide diffusion capacity, pulmonary function outcomes, and overall survival. In both bleomycin- and radiation-induced pulmonary fibrosis murine models, hLYCAT overexpression reduced several indices of lung fibrosis, whereas down-regulation of native LYCAT expression by siRNA accentuated fibrogenesis. In vitro studies demonstrated that LYCAT modulated bleomycin-induced cardiolipin remodeling, mitochondrial membrane potential, reactive oxygen species generation, and apoptosis of alveolar epithelial cells, potential mechanisms of LYCAT-mediated lung protection.

CONCLUSIONS

This study is the first to identify modulation of LYCAT expression in fibrotic lungs and offers a novel therapeutic approach for ameliorating lung inflammation and pulmonary fibrosis.

Allele Frequencies of the Epidermal Growth Factor Receptors Polymorphism R521K in Colorectal Cancer Patients and Healthy Subjects Indicate a Risk-Reducing Effect of K521 in Syrian Population

Background:

Colorectal cancer contributes heavily to cancer morbidity and mortality worldwide. Numerous therapies are currently in use, including monoclonal antibodies against cellular components involved in tumorigenesis such as epidermal growth factor receptors (EGFRs). Studies showed the polymorphism [R521K] GàA in the EGFR gene to be involved in both colorectal cancer susceptibility and clinical response to therapeutics (e.g., Cetuximab).

Aim:

We aimed at uncovering allele frequencies of this polymorphism among Syrian colorectal cancer patients and healthy individuals.

Materials and Methods:

Forty-seven patients with colorectal cancer were included in a case-control study along with 48 healthy subjects, all native Syrians. Individuals were genotyped using PCR-Restriction Fragment Length Polymorphism (PCR-RFLP) and results were statistically analyzed to elucidate significant differences between the two groups.

Results:

Allele frequencies were 40.4% (G/G), 57.4% (G/A) and 2.1% (A/A) in colorectal cancer patients and 41.6% (G/G), 43.7% (G/A) and 14.5% (A/A) in healthy subjects. The A/A genotype was significantly lower in colorectal cancer patients than in the control group.

Conclusions:

Homozygosity for the A allele is linked to reducing the risk of developing colorectal cancer in Syrian patients. The lower prevalence of (A/A) locally may predict sub-optimal rates of clinical response to Cetuximab compared with populations with higher frequencies of the A allele. Larger scale investigations are needed for a stronger conclusion.