TWEAK transactivation of the epidermal growth factor receptor mediates renal inflammation

TWEAK, a member of the TNF superfamily, binds to the Fn14 receptor, eliciting biological responses. EGFR signalling is involved in experimental renal injury. Our aim was to investigate the relationship between TWEAK and EGFR in the kidney. Systemic TWEAK administration into C57BL/6 mice increased renal EGFR phosphorylation, mainly in tubular epithelial cells. In vitro, in these cells TWEAK phosphorylated EGFR via Fn14 binding, ADAM17 activation and subsequent release of the EGFR ligands HB‐EGF and TGFα. In vivo the EGFR kinase inhibitor Erlotinib inhibited TWEAK‐induced renal EGFR activation and downstream signalling, including ERK activation, up‐regulation of proinflammatory factors and inflammatory cell infiltration. Moreover, the ADAM17 inhibitor WTACE‐2 also prevented those TWEAK‐induced renal effects. In vitro TWEAK induction of proinflammatory factors was prevented by EGFR, ERK or ADAM17 inhibition. In contrast, EGFR transactivation did not modify TWEAK‐mediated NF‐κB activation. Our data suggest that TWEAK transactivates EGFR in the kidney, leading to modulation of downstream effects, including ERK activation and inflammation, and suggest that inhibition of EGFR signalling could be a novel therapeutic tool for renal inflammation. Copyright © 2013 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.     

Activating HRAS mutation in a case of inverted ductal papilloma of the salivary gland

Inverted ductal papilloma (IDP) is one of the least common benign papillary/cystic neoplasms of the salivary duct system, being characterized histologically by florid hyperplasia of duct-type epithelial cells into a cystic lumen near the orifice with occasional endophytic growth of the surface squamous epithelium along the terminus of the affected excretory duct. Given its rarity, the exact etiology of IDP remains to be defined. We herein present the first evidence of oncogenic HRAS mutation in a case of oral IDP. This finding, together with the frequent and specific BRAF mutations in sialadenoma papilliferum reported in the recent literature, supports an active role of the MAP-kinase cascade in the pathogenesis of benign papillary neoplasms of terminal duct origin.     

EGFR-Targeted Therapy for Non-Small Cell Lung Cancer: Focus on EGFR Oncogenic Mutation

The two essential requirements for pathologic specimens in the era of personalized therapies for non-small cell lung carcinoma (NSCLC) are accurate subtyping as adenocarcinoma (ADC) versus squamous cell carcinoma (SqCC) and suitability for EGFR molecular testing, as well as for testing of other oncogenes such as EML4-ALK and KRAS. Actually, the value of EGFR expressed in patients with NSCLC in predicting a benefit in terms of survival from treatment with an epidermal growth factor receptor targeted therapy is still in debate, while there is a convincing evidence on the predictive role of the EGFR mutational status with regard to the response to tyrosine kinase inhibitors (TKIs).This is a literature overview on the state-of-the-art of EGFR oncogenic mutation in NSCLC. It is designed to highlight the preclinical rationale driving the molecular footprint assessment, the progressive development of a specific pharmacological treatment and the best method to identify those NSCLC who would most likely benefit from treatment with EGFR-targeted therapy. This is supported by the belief that a rationale for the prioritization of specific regimens based on patient-tailored therapy could be closer than commonly expected.     

Overview of high-risk HPV's 16 and 18 infected cervical cancer: Pathogenesis to prevention

As general, the Human papillomavirus (HPV) causes the most sexually transmitted diseases. Among well categorized 80 types, the high-risk types HPV's 16 and 18 are highly involved in 70% of cervical cancer. The virulence of HPV is mainly exhibited by E5, E6 and E7 encoded oncoproteins that cause low to high-grade cervical lesions (CIN-1, 2, 3), leading to form 99.7% of squamous cell and 89% of adenocarcinomas cervical cancer worldwide. This study mainly encircles the major role of E5, E6 and E7 oncoproteins in HPV 16 and 18. Further discussed the uprising of significant biomarkers and their cellular process in different stages of cervical cancer with current prevention and treatment regimens. Hence, this integration will evoke novel markers, potential vaccination and various treatments approaches with special reference for HPV16 and 18 infected cervical cancers.     

Bile salt-induced apoptosis involves NADPH oxidase isoform activation

BACKGROUND & AIMS: Hydrophobic bile salts trigger a rapid oxidative stress response as an upstream event of CD95 activation and hepatocyte apoptosis. METHODS: The underlying mechanisms were studied by Western blot, immunocytochemistry, protein knockdown, and fluorescence resonance energy transfer microscopy in rat hepatocytes and human hepatoma cell line 7 (Huh7). RESULTS: The rapid oxidative stress formation in response to taurolithocholate-3-sulfate (TLCS) was inhibited by diphenyleneiodonium, apocynin, and neopterin, suggestive for the involvement of nicotinamide adenine dinucleotide phosphate (NADPH) oxidases. TLCS induced a rapid serine phosphorylation of the regulatory subunit p47phox, which was sensitive to inhibition of sphingomyelinase and protein kinase Czeta (PKCzeta). Inhibitors of p47phox phosphorylation and p47phox protein knockdown abolished the TLCS-induced oxidative stress response and blunted subsequent CD95 activation. Consequences of TLCS-induced oxidative stress were c-Jun-N-terminal kinase activation and Yes-dependent activation of the epidermal growth factor receptor (EGFR), followed by EGFR-catalyzed CD95 tyrosine phosphorylation, formation of the death-inducing signaling complex, and execution of apoptosis. As shown by fluorescence resonance energy transfer experiments in Huh7 cells, TLCS induced a c-Jun-N-terminal kinase-dependent EGFR/CD95 association in the cytosol and trafficking of this protein complex to the plasma membrane. Inhibition of EGFR tyrosine kinase activity by AG1478 allowed for cytosolic EGFR/CD95 association, but prevented targeting of the EGFR/CD95 complex to the plasma membrane. Both processes, and TLCS-induced Yes and EGFR activation, were sensitive to inhibition of sphingomyelinase, PKCzeta, or NADPH oxidases. CONCLUSIONS: The data suggest that hydrophobic bile salts activate NADPH oxidase isoforms with the resulting oxidative stress response triggering activation of the CD95 system and apoptosis.     

Trefoil factor 3 in perinatal pancreas is increased by gestational low protein diet and associated with accelerated β-cell maturation

The endocrine pancreas expands markedly in the first postnatal days and the insulin producing β-cells initiate a functional maturation preceded by a morphological change of the islets of Langerhans. Trefoil factor 3 (TFF3) is a secreted peptide expressed in intestinal epithelia, where it promotes migration, but its role in the pancreas is not characterized. The aim of this study was to examine the expression and function of TFF3 in perinatal rat pancreas, ex vivo cultured fetal rat pancreas and in the rat β-cell line INS-1E.

Control or gestational low-protein diet perinatal rat pancreas was harvested at embryonic day 20 (E20), day of birth (P0) and postnatal day 2 (P2). TFF3 mRNA was upregulated 4.5-fold at P0 vs. E20 and downregulated again at P2. In protein-undernourished pups induction of TFF3 at P0 was further increased to 9.7-fold and was increased at P2. TFF3 caused tyrosine phosphorylation of EGFR in INS-1E β-cells, and purified recombinant TFF3 increased both attachment and spreading of INS-1E β-cells. In ex vivo cultures of collagenase digested fetal rat pancreas, a model of perinatal β-cell maturation, TFF3 increased cellular spreading as well as insulin mRNA levels. TFF3 also increased the expression of Pref1/Dlk1 that shares similarities in expression and regulation with TFF3.

These results suggest that TFF3 may promote adhesion and spreading of cells to accelerate β-cell maturation. This study indicates a functional role for TFF3 in pancreatic β-cell maturation in the perinatal period, which is altered by low protein diet during gestation.     

ShcC proteins: Brain aging and beyond

To date, most studies of Shc family of signaling adaptor proteins have been focused on the near-ubiquitously expressed ShcA, indicating its relevance to age-related diseases and longevity. Although the role of the neuronal ShcC protein is much less investigated, accumulated evidence suggests its importance for neuroprotection against such aging-associated conditions as brain ischemia and oxidative stress. Here, we summarize more than decade of studies on the ShcC expression and function in normal brain, age-related brain pathologies and immune disorders with a focus on the interactions of ShcC with signaling proteins/pathways, and the possible implications of these interactions for changes associated with aging.     

益气化瘀解毒法对慢性萎缩性胃炎伴异型增生大鼠EGFR/MAPK信号通路的影响

目的观察益气化瘀解毒法对慢性萎缩性胃炎(CAG)伴异型增生(Dys)模型大鼠EGFR/MAPK信号通路的影响。方法 60只SPF级健康雄性Wistar大鼠随机分为空白组10只,造模组50只。空白组给予SPF级动物标准饮食喂养,持续至实验结束。造模组采用以120 mg/L的N-甲基-N'-硝基-N-亚硝基胍(MNNG)溶液灌胃,每只5 m L/kg,1次/d为主,配合自由饮用0.1%氨水溶液及进食含0.03%雷尼替丁的颗粒状饲料,3种因素联合建立CAG伴Dys大鼠模型。28周末造模成功后将造模组剩余的30只大鼠随机分为模型组、维酶素组、益气化瘀解毒法组(中药组),每组各10只,均给予SPF级动物标准饮食喂养,并且每天灌胃1次,维酶素组予维酶素悬浊液2 m L/kg(即维酶素0.3 g/kg),中药组予益气化瘀解毒中药3 m L/kg(含生药9 g/kg),模型组予生理盐水3m L/kg。12周后即实验第40周末处死全部大鼠。选用Western blot法对各组大鼠胃窦部黏膜组织中EGFR、ERK1/2、p-ERK1/2蛋白表达进行检测。结果模型组EGFR蛋白表达最高,其次是维酶素组、中药组、空白组;其中,模型组与空白组和中药组比较均有显著性差异(均P0.01),中药组与维酶素组比较有显著性差异(P0.05)、与空白组比较无显著性差异(P0.05)。模型组ERK1/2蛋白表达最高,其次是维酶素组、中药组、空白组;其中,模型组、维酶素组与空白组和中药组比较均有显著性差异(均P0.01),中药组与空白组比较也有显著性差异(P0.01)。模型组p-ERK1/2蛋白表达最高,其次是维酶素组、中药组、空白组;其中,模型组与空白组和中药组比较均有显著性差异(均P0.01),中药组与维酶素组有显著性差异(P0.01)、与空白组比较无显著性差异。结论益气化瘀解毒法可显著抑制EGFR的高表达及EGFR/MAPK细胞信号转导通路的异常激活,这可能是其治疗CAG伴Dys、逆转胃癌前病变(PLGC)、防治胃癌的有效作用机制之一。     

Liquid biopsy is a valuable tool in the diagnosis and management of lung cancer

Liquid biopsy refers to the use of various body fluids to test for circulating biological elements derived from the tumor. Liquid biopsy has taken on an increasingly important role in lung cancer diagnosis, molecular characterization, surveillance, monitoring, and determining mechanisms of resistance. These assays can utilize various sources of cell-free DNA (cfDNA) including blood, pleural fluid, urine, and others to detect tumor associated alterations. With the increasing power of next-generation sequencing technologies and the development of assays such as digital droplet PCR, rare tumor alleles can be detected in cfDNA to determine key characteristics of the tumor. Current assays, while effective, are still challenged by limited sensitivity and capacity to single genes or small panels of genes, though this is rapidly expanding. Nevertheless, testing of cfDNA has been shown to be valuable in detecting resistance to targeted inhibitors, particularly for detection of T790M in EGFR and monitoring response to therapy. With the continued development of more powerful and sensitive assays, these techniques will empower clinicians to better characterize early stage disease and can be used in the screening of high-risk patients, which may eliminate the requirement for tissue diagnosis in some settings. That said, since the majority of these alterations are not specific to lung cancer, there will continue to be a need for tissue in at least the initial diagnosis. Used in conjugation with tissue sampling, these assays will assist the treating clinician and the pathologist to better characterize individual tumors, even in the setting of limited tissue.