LRIG1 modulates aggressiveness of head and neck cancers by regulating EGFR-MAPK-SPHK1 signaling and extracellular matrix remodeling.

EGFR overexpression and chromosome 3p deletion are two frequent events in head and neck cancers. We previously mapped the smallest region of recurrent copy-number loss at 3p12.2-p14.1. LRIG1, a negative regulator of EGFR, was found at 3p14, and its copy-number loss correlated with poor clinical outcome. Inducible expression of LRIG1 in head and neck cancer TW01 cells, a line with low LRIG1 levels, suppressed cell proliferation in vitro and tumor growth in vivo. Gene expression profiling, quantitative RT-PCR, chromatin immunoprecipitation, and western blot analysis demonstrated that LRIG1 modulated extracellular matrix (ECM) remodeling and EGFR-MAPK-SPHK1 transduction pathway by suppressing expression of EGFR ligands/activators, MMPs and SPHK1. In addition, LRIG1 induction triggered cell morphology changes and integrin inactivation, which coupled with reduced SNAI2 expression. By contrast, knockdown of endogenous LRIG1 in TW06 cells, a line with normal LRIG1 levels, significantly enhanced cell proliferation, migration and invasiveness. Such tumor-promoting effects could be abolished by specific MAPK or SPHK1 inhibitors. Our data suggest LRIG1 as a tumor suppressor for head and neck cancers; LRIG1 downregulation in cancer cells enhances EGFR-MAPK-SPHK1 signaling and ECM remodeling activity, leading to malignant phenotypes of head and neck cancers.

IL-10 and TNF-alpha promoter polymorphisms in susceptibility to systemic lupus erythematosus in Taiwan.

OBJECTIVES: The genetic control of Interleukin-10 (IL-10) and Tumour necrosis factor-alpha (TNF-alpha) production and the possible interaction between the two cytokines in influencing SLE susceptibility as well as clinical features has not been completely evaluated in the Taiwanese population. METHODS: We investigated the association of IL-10 and TNF-alpha promoter polymorphisms (-1082, -819 and -592 for IL-10 gene; -308 for TNF-alpha gene) with SLE in a total of 172 Taiwanese patients and 215 controls. RESULTS: Our results indicate that IL-10 A/T/A-A/T/A genotype was associated with Taiwanese SLE, whereas no significance was observed between TNF-alpha genotype and SLE. Furthermore, the TNF-alpha G allele frequency of the polymorphism at -308 was significantly decreased in patients with oral ulcers. The combined frequencies of IL-10 A/T/A haplotype and TNF-alpha G-G genotype were significantly increased in SLE patients. In addition, the combined frequencies of IL-10 A/T/A haplotype and TNF-alpha G-G genotype were significantly decreased in patients with oral ulcers. CONCLUSIONS: These results suggest a significant correlation of the combined IL-10 and TNF-alpha genetic polymorphisms contribute to SLE susceptibility and clinical features in the Taiwanese population.

A/C polymorphism in the interleukin-18 coding region among Taiwanese systemic lupus erythematosus patients.

Interleukin-18 (IL-18) is associated with chronic inflammation, autoimmune diseases and various cancers and infectious diseases. An IL-18 genetic A/C polymorphism at coding position 105 (rs549908) has been linked with asthma and rheumatoid arthritis. We tested a hypothesis that the IL-18 genetic polymorphism confers systemic lupus erythematosus (SLE) susceptibility. Study participants were Taiwanese SLE patients and a healthy control group. Our results indicate (1) a significantly higher A allele frequency in SLE patients (P = 0.003; OR = 1.97; 95% CI = 1.26-3.08) and (2) a significantly higher A allele frequency in SLE patients with a central nervous system disorder (P = 0.027; OR = 7.18; 95% CI = 0.95-54.28). Our results suggest that the A/C polymorphism contributes to SLE pathogenesis.