Enhanced TGFalpha-EGFR expression and P53 gene alterations contributes to gastric tumors aggressiveness

Isoforms of the p53 Family and Gastric Cancer: A Ménage à Trois for an Unfinished Affair

Simple Summary

The p53 family is a complex family of transcription factors with different cellular functions that are involved in several physiological processes. A massive amount of data has been accumulated on their critical role in the tumorigenesis and the aggressiveness of cancers of different origins. If common features are observed, there are numerous specificities that may reflect particularities of the tissues from which the cancers originated. In this regard, gastric cancer tumorigenesis is rather remarkable, as it is induced by bacterial and viral infections, various chemical carcinogens, and familial genetic alterations, which provide an example of the variety of molecular mechanisms responsible for cell transformation and how they impact the p53 family. This review summarizes the knowledge gathered from over 40 years of research on the role of the p53 family in gastric cancer, which still displays one of the most elevated mortality rates amongst all types of cancers.

Abstract

Gastric cancer is one of the most aggressive cancers, with a median survival of 12 months. This illustrates its complexity and the lack of therapeutic options, such as personalized therapy, because predictive markers do not exist. Thus, gastric cancer remains mostly treated with cytotoxic chemotherapies. In addition, less than 20% of patients respond to immunotherapy. TP53 mutations are particularly frequent in gastric cancer (±50% and up to 70% in metastatic) and are considered an early event in the tumorigenic process. Alterations in the expression of other members of the p53 family, i.e., p63 and p73, have also been described. In this context, the role of the members of the p53 family and their isoforms have been investigated over the years, resulting in conflicting data. For instance, whether mutations of TP53 or the dysregulation of its homologs may represent biomarkers for aggressivity or response to therapy still remains a matter of debate. This uncertainty illustrates the lack of information on the molecular pathways involving the p53 family in gastric cancer. In this review, we summarize and discuss the most relevant molecular and clinical data on the role of the p53 family in gastric cancer and enumerate potential therapeutic innovative strategies.

Influence of the HER receptor ligand system on sensitivity to cetuximab and trastuzumab in gastric cancer cell lines

Purpose

Gastric cancer remains a major health concern, and improvement of the therapeutic options is crucial. Treatment with targeted therapeutics such as the EGFR-targeting antibody cetuximab or the HER2-targeting antibody trastuzumab is either ineffective or moderately effective in this disease, respectively. In this study, we analysed the involvement of the HER receptor ligands amphiregulin (AREG), epidermal growth factor (EGF), heparin-binding epidermal growth factor (HB-EGF) and transforming growth factor alpha (TGFα) in the responsiveness of gastric cancer cell lines to cetuximab and trastuzumab.

Methods

A panel of 11 gastric cancer cell lines was characterized for cetuximab and trastuzumab sensitivity, ligand secretion and expression and activation of the HER receptors using WST-1 cell proliferation assays, ELISAs and Western blot analyses. We further investigated the effects of an exogenous ligand application on the cetuximab and trastuzumab sensitivity.

Results

We found no correlation between TGFα secretion and the sensitivity to cetuximab or trastuzumab. For AREG, we confirmed previous results indicating that this ligand is a positive predictor of cetuximab sensitivity. Exogenous HB-EGF was effective in rescuing sensitive cell lines from inhibition of cell proliferation by both, cetuximab and trastuzumab.

Conclusions

Our data indicate that HB-EGF may be a useful marker for the prediction of trastuzumab sensitivity in gastric cancer.

Electronic supplementary material

The online version of this article (doi:10.1007/s00432-016-2308-z) contains supplementary material, which is available to authorized users.

Input of microenvironmental regulation on colorectal cancer: Role of the CCN family

Colorectal cancer (CRC) is a major health problem causing significant morbidity and mortality. Previous results from various studies indicate that CRC tumorigenicity encompasses tumor microenvironment, emphasizing the complex interacting network between cancer cells and nearby host cells, which triggers diverse signaling pathways to promote the growth and spread of cancer cells. The CCN family proteins share a uniform modular structure, mediating a variety of physiological functions, including proliferation, apoptosis, migration, adhesion, differentiation, and survival. Furthermore, CCN proteins are also involved in CRC initiation and development. Many studies have shown that CCN members, such as CCN1, CCN2, CCN3, Wnt-induced secreted protein (WISP)-1, WISP-2, and WISP-3, are dysregulated in CRC, which implies potential diagnostic markers or therapeutic targets clinically. In this review, we summarize the research findings on the role of CCN family proteins in CRC initiation, development, and progression, highlighting their potential for diagnosis, prognosis, and therapeutic application.

TGF-α gene variations and increased susceptibility of gastric cancer in an Eastern Chinese Han population

Transforming growth factor-alpha (TGF-α) correlates with deep invasion, advanced stage and poor prognosis in gastric cancer. Genetic variants in the 3' untranslated region (UTR) of TGF-α gene may influence the stability and post-transcriptional regulation of mRNA and contribute to gastric cancer predisposition. To test this hypothesis, we genotyped five polymorphisms in 3'UTR (rs3771527, rs503314, rs473698, rs3732253 and rs538118) and one in 3' near region (rs11466306) of the TGF-α gene by polymerase chain reaction-ligation detection reaction methods (PCR-LDR). We found that GA/AA genotype of rs11466306 in the 3' near gene could increase the risk of overall gastric cancer (adjusted OR = 1.499, 95%CI: 1.101-2.041), compared to the wild homozygous GG genotype. Meanwhile, the risk effect was more obvious in the intestinal gastric cancer and gastric noncardia cancer (adjusted OR = 1.682, 95%CI: 1.188-2.380; adjusted OR = 1.495, 95%CI: 1.072-2.086, respectively), but not for the diffuse type and gastric cardia cancer (p > 0.05). CT/TT genotype for rs3732253 in the 3' UTR was associated with increased risk of intestinal gastric cancer (adjusted OR = 1.464, 95%CI: 1.036-2.069), compared to their wild homozygous genotypes. These findings indicate that potentially functional TGF-α gene variant may contribute to the risk of intestinal gastric cancer and/or gastric noncardia cancer and could be used as molecular markers for detecting intestinal gastric cancer and/or gastric noncardia cancer in Chinese Han population.

Canine gastric carcinoma: immunohistochemical expression of cell cycle proteins (p53, p21, and p16) and heat shock proteins (Hsp27 and Hsp70)

Immunohistochemical staining for cell cycle proteins and heat shock proteins was performed on 17 canine gastric carcinomas. The immunoexpression of p53, p21, p16, Hsp27, and Hsp70 was investigated. A study was conducted to determine the histological type and parameters related to tumor malignancy. Possible associations and trends were assessed between the immunoexpression of each protein and tumor type as well as specific parameters of malignancy. High intratumor frequency of cellular p53 immunostaining was observed (61.96% average), but lower frequencies of p21 and p16 expression were present (34.65% and 10.41%, respectively). The p53 overexpression was associated with tumor infiltration (P = .0258). Expression of p21 was lower in undifferentiated carcinomas, and the loss of expression was associated with histopathological parameters characteristic of a poor prognosis such as lymphatic vessel invasion (P = .0258). The lack of p16 immunoreactivity was related to histopathological characteristics of malignancy such as the presence of evident and multiple nucleoli (P = .0475). In contrast, deep tumor infiltration was observed in those carcinomas with a high p16 index (P = .0475). Hsp70 appeared to be overexpressed in all gastric neoplasms included in this study. This is in contrast to Hsp27, because a group of tumors showed complete lack of Hsp27 immunoexpression, whereas the others displayed extensive Hsp27 immunostaining. The differences in Hsp27 did not correlate with any of the histopathological parameters, but Hsp27 immunoexpression was higher in the undifferentiated carcinoma. No significant differences in the expression of the proteins were found in canine gastric carcinomas according to their histological type. These findings may be useful for establishing a prognosis for canine gastric carcinoma.

Expression of transforming growth factor α and Cyclin E and their correlation in chronic gastric lesion tissues from patients with different TCM types

AIM: To explore the expression of transforming growth factor α (TGF-α) and Cyclin E in chronic gastric lesion tissues from patients with different types of traditional Chinese medicine (TCM), and analyze the correlation between TGF-α and Cyclin E expression.

METHODS: The patients (n = 135) with chronic gastric diseases were classified to 4 groups according to different TCM types such as disharmony between liver and stomach (group A), spleen-stomach cold deficiency (group B), stomach-yin deficiency (group C), and mixed cold and heat (group D). Immunohistochemical staining was used to examine the expression of TGF-α and Cyclin E in the lesion tissues and the correlation between TGF-α and Cyclin E expression was also ssessed.

RESULTS: The positive rates of TGF-α expression in the lesion tissues of group A, B, C and D were 25.0%, 18.6%, 47.1% and 42.1%, respectively, and there was significant difference between group B and C (P < 0.05). The positive rates of Cyclin E expression were 20.0%, 7.0%, 26.5% and 31.6%, respectively, and there was marked difference between group B and D (P < 0.05). Both TGF-α and Cyclin E expression were the lowest in group B, and there existed a positive correlation between the expression of TGF-α and Cyclin E.

CONCLUSION: TGF-α and Cyclin E are differentially expressed in chronic gastric lesion tissues of patients with different TCM types, and the expression of TGF-α and Cyclin E are positively correlated.

The status and role of ErbB receptors in human cancer

Changes in the expression of cellular receptors contribute to the progression of many types of solid tumors. In this review, we focus on the normal role of ErbB receptors as signal transducers and their contribution to carcinogenesis when there are abnormalities in ErbB signaling due to the overactivity of the receptors or the overexpression of ligands, which can lead to developmental defects and have been associated with many types of cancers.

Expression of JP-8–Induced Inflammatory Genes in AEII Cells Is Mediated by NF-κB and PARP-1

Lung epithelial cells are critical in the regulation of airway inflammation in response to environmental pollutants. Altered activation of NF-kappaB is associated with expression of several proinflammatory factors in respiratory epithelial cells in response to an insult. Here we show that a low threshold dose (8 microg/ml) of the jet fuel JP-8 induces in a rat alveolar epithelial cell line (RLE-6TN) a prolonged activation of NF-kappaB as well as the increased expression of the proinflammatory cytokines TNF-alpha and IL-8, which are regulated by NF-kappaB. The up-regulation of IL-6 mRNA in cells exposed to JP-8 appears to be a reaction of RLE-6TN cells to reduce the enhancement of proinflammatory mediators in response to the fuel. Moreover, lung tissues from rats exposed to occupational levels of JP-8 by nasal aerosol also showed dysregulated expression of TNF-alpha, IL-8, and IL-6, confirming the in vitro data. The poly(ADP-ribosyl)ation of PARP-1, a coactivator of NF-kappaB, was coincident with the prolonged activation of NF-kappaB during JP-8 treatment. These results evidenced that a persistent exposure of the airway epithelium to aromatic hydrocarbons may have deleterious effects on pulmonary function.

Role of receptor tyrosine kinases in gastric cancer: New targets for a selective therapy

Receptor tyrosine kinases (RTKs) such as the epidermal growth factor receptor family participate in several steps of tumor formation including proliferation and metastatic spread. Several known RTKs are upregulated in gastric cancer being prime targets of a tailored therapy. Only preliminary data exist, however, on the use of the currently clinically available drugs such as trastuzumab, cetuximab, bevacizumab, gefitinib, erlotinib, and imatinib in the setting of gastric cancer. Preclinical data suggest a potential benefit of their use, especially in combination with “conventional” cytostatic therapy. This review summarizes the current knowledge about their use in cancer therapy as well as new approaches and drugs to optimize treatment success.