Stress Hormone Cortisol Enhances Bcl2 Like-12 Expression to Inhibit p53 in Hepatocellular Carcinoma Cells

Wip1 contributes to the adaptation of HepG2 human liver cancer cells to stress hormone-induced DNA damage

Numerous studies have shown that the release of stress hormones resulting from repeated exposure to chronic psychological stress increases DNA damage and promotes tumorigenesis. However, the mechanisms that enable cancerous cells adapt to stress hormone-induced DNA damage and survive remain unclear. The present study aimed to investigate the impact of stress hormones on the survival of liver cancer cells and the underlying mechanism. HepG2 human liver cancer cells were treated with dexamethasone (DEX), epinephrine (EPI) and norepinephrine (NE) and subjected to the testing of DNA damage, cell survival and cell apoptosis by alkaline comet assay, CCK-8 viability assay and flow cytometry, respectively. The protein expression levels of DNA damage response factors were determined by western blotting analysis. The results revealed that treatment of HepG2 cells with DEX, EPI and NE induced DNA damage without affecting cell survival or inducing apoptosis. The protein levels of wild-type p53-induced phosphatase 1 (Wip1), a type 2C family serine/threonine phosphatase, were increased, and the dephosphorylation of DNA damage response factors, including phosphorylated (p-)ataxia-telangiectasia mutated and p-checkpoint kinase 2, occurred following treatment with DEX, EPI and NE. In addition, a cycloheximide chase assay was performed to explore the protein stability under treatment with stress hormones. Compared with vehicle-treated cells, Wip1 exhibited increased protein stability in stress hormone-treated HepG2 cells. Eventually, the depletion of Wip1 using small interfering RNA verified the role of Wip1 in the modulation of stress hormone-induced DNA damage. These findings suggest that cancerous cells likely adapt to stress hormone-induced DNA damage via Wip1 upregulation. The present study provides an insight into the underlying mechanism that links chronic psychological stress with tumor growth and progression.

Stress and cancer: The mechanisms of immune dysregulation and management

Advances in the understanding of psychoneuroimmunology in the past decade have emphasized the notion that stress and cancer are interlinked closely. Durable chronic stress accelerated tumorigenesis and progression, which is unfavorable for clinical outcomes of cancer patients. Available evidence has provided unprecedented knowledge about the role and mechanisms of chronic stress in carcinogenesis, the most well-known one is dysfunction of the hypothalamus-pituitary-adrenal (HPA) axis and the sympathetic nervous system (SNS). With abnormal activation of neuroendocrine system, stress-related hormones contribute to increased oncogenes expression, exacerbated chronic inflammation and impaired immunologic function. In addition, accumulating studies have demonstrated that diverse stress interventions including pharmacological approaches, physical exercises and psychological relaxation have been administered to assist in mental disorders reduction and life quality improvement in cancer patients. In this review, we systematically summarize the connection and mechanisms in the stress-immune-cancer axis identified by animal and clinical studies, as well as conclude the effectiveness and deficiencies of existing stress management strategies.

Early Social Enrichment Modulates Tumor Progression and p53 Expression in Adult Mice

Epidemiological evidence indicates that stress and aversive psychological conditions can affect cancer progression, while well-being protects against it. Although a large set of studies have addressed the impact of stress on cancer, not much is known about the mechanisms that protect from cancer in healthy psychological conditions. C57BL/6J mouse pups were exposed to an environmental enrichment condition consisting of being raised until weaning by the biological lactating mother plus a non-lactating virgin female (LnL = Lactating and non-Lactating mothers). The Control group consisted of mice raised by a single lactating mother (L = Lactating). Four months after weaning, mice from LnL and L conditions were exposed to intramuscular injection of 3-methylcolantrene (3MCA), a potent tumorigenic drug, and onset and progression of 3MCA-induced fibrosarcomas were monitored over time. Pups from the LnL compared to the L group received more parental care and were more resilient to stressful events during the first week of life. In association, the onset of tumors in LnL adults was significantly delayed. At the molecular level, we observed increased levels of wild-type p53 protein in tumor samples of LnL compared to L adults and higher levels of its target p21 in healthy muscles of LnL mice compared to the L group, supporting the hypothesis of potential involvement of p53 in tumor development. Our study sustains the model that early life care protects against tumor susceptibility.

Chronic Stress Effects on Tumor: Pathway and Mechanism

Chronic stress is an emotional experience that occurs when people encounter something they cannot adapt to. Repeated chronic stress increases the risk of a variety of diseases, such as cardiovascular disease, depression, endocrine disease, inflammation and cancer. A growing body of research has shown that there is a link between chronic stress and tumor occurrence in both animal studies and clinical studies. Chronic stress activates the neuroendocrine system (hypothalamic-pituitary-adrenal axis) and sympathetic nervous system. Stress hormones promote the occurrence and development of tumors through various mechanisms. In addition, chronic stress also affects the immune function of the body, leading to the decline of immune monitoring ability and promote the occurrence of tumors. The mechanisms of chronic stress leading to tumor include inflammation, autophagy and epigenetics. These factors increase the proliferation and invasion capacity of tumor cells and alter the tumor microenvironment. Antagonists targeting adrenergic receptors have played a beneficial role in improving antitumor activity, as well as chemotherapy resistance and radiation resistance. Here, we review how these mechanisms contribute to tumor initiation and progression, and discuss whether these molecular mechanisms might be an ideal target to treat tumor.

Interaction between Ras and Bcl2L12 in B cells suppresses IL-10 expression

The pathogenesis of recurrent tonsillitis is to be further investigated. B cell-derived interleukin (IL)-10 plays a critical role in immune regulation. Ras activation plays an important role in cancer and many immune disorders. This study aims to investigate the role of Ras activation in down regulating IL-10 expression in tonsillar B cells. Surgically removed tonsil tissues were collected from patients with recurrent acute tonsillar inflammation; B cells were isolated from the tonsillar tissues by flow cytometry sorting to be analyzed by the Ras-specific enzyme-linked immunosorbent assay and pertinent immunological approaches. We found that, compared to peripheral B cells (pBC), B cells isolated from the tonsillar tissues with recurrent inflammation (tBC) showed higher Ras activation, lower IL-10 expression and higher Bcl2L12 expression. Bcl2L12 formed a complex with GAP (GTPase activating protein) to prevent Ras from deactivating. The Ras activation triggered the MAPK/Sp1 pathway to promote the Bcl2L12 expression in B cells. Bcl2L12 prevented the IL-10 expression in tBCs, that was counteracted by inhibition of Ras or the Ras signal transduction pathway. In conclusion, Bcl2L12 interacts with Ras activation to compromise immune tolerance in the tonsils by inhibiting the IL-10 expression in tBCs. Inhibition of Bcl2L12 can restore the IL-10 expression in tBCs.

Perception of breast cancer risk factors: Dysregulation of TGF-β/miRNA axis in Pakistani females

Breast cancer poses a serious health risk for women throughout the world. Among the Asian population, Pakistani women have the highest risk of developing breast cancer. One out of nine women is diagnosed with breast cancer in Pakistan. The etiology and the risk factor leading to breast cancer are largely unknown. In the current study the risk factors that are most pertinent to the Pakistani population, the etiology, molecular mechanisms of tumor progression, and therapeutic targets of breast cancer are studied. A correlative, cross-sectional, descriptive, and questionnaire-based study was designed to predict the risk factors in breast cancer patients. Invasive Ductal Carcinoma (90%) and grade-II tumor (73.2%) formation are more common in our patient’s data set. Clinical parameters such as mean age of 47.5 years (SD ± 11.17), disturbed menstrual cycle (> 2), cousin marriages (repeated), and lactation period (< 0.5 Y) along with stress, dietary and environmental factors have an essential role in the development of breast cancer. In addition to this in silico analysis was performed to screen the miRNA regulating the TGF-beta pathway using TargetScanHuman, and correlation was depicted through Mindjet Manager. The information thus obtained was observed in breast cancer clinical samples both in peripheral blood mononuclear cells, and biopsy through quantitative real-time PCR. There was a significant dysregulation (**P>0.001) of the TGF-β1 signaling pathway and the miRNAs (miR-29a, miR-140, and miR-148a) in patients’ biopsy in grade and stage specifically, correlated with expression in blood samples. miRNAs (miR-29a and miR-140, miR-148a) can be an effective diagnostic and prognostic marker as they regulate SMAD4 and SMAD2 expression respectively in breast cancer blood and biopsy samples. Therefore, proactive therapeutic strategies can be devised considering negatively regulated cascade genes and amalgamated miRNAs to control breast cancer better.

Xmrks the Spot: Fish Models for Investigating Epidermal Growth Factor Receptor Signaling in Cancer Research

Studies conducted in several fish species, e.g., Xiphophorus hellerii (green swordtail) and Xiphophorus maculatus (southern platyfish) crosses, Oryzias latipes (medaka), and Danio rerio (zebrafish), have identified an oncogenic role for the receptor tyrosine kinase, Xmrk, a gene product closely related to the human epidermal growth factor receptor (EGFR), which is associated with a wide variety of pathological conditions, including cancer. Comparative analyses of Xmrk and EGFR signal transduction in melanoma have shown that both utilize STAT5 signaling to regulate apoptosis and cell proliferation, PI3K to modulate apoptosis, FAK to control migration, and the Ras/Raf/MEK/MAPK pathway to regulate cell survival, proliferation, and differentiation. Further, Xmrk and EGFR may also modulate similar chemokine, extracellular matrix, oxidative stress, and microRNA signaling pathways in melanoma. In hepatocellular carcinoma (HCC), Xmrk and EGFR signaling utilize STAT5 to regulate cell proliferation, and Xmrk may signal through PI3K and FasR to modulate apoptosis. At the same time, both activate the Ras/Raf/MEK/MAPK pathway to regulate cell proliferation and E-cadherin signaling. Xmrk models of melanoma have shown that inhibitors of PI3K and MEK have an anti-cancer effect, and in HCC, that the steroidal drug, adrenosterone, can prevent metastasis and recover E-cadherin expression, suggesting that fish Xmrk models can exploit similarities with EGFR signal transduction to identify and study new chemotherapeutic drugs.

Combined effect of recombinant human adenovirus p53 and curcumin in the treatment of liver cancer

The development of an effective therapeutic intervention for liver cancer is a worldwide challenge that remains to be adequately addressed. Of note, TP53, which encodes the p53 protein, is an important tumor suppressor gene, 61% of TP53 is functionally inactivated in liver cancer. Recombinant human adenovirus p53 (rAd-p53) is the first commercial product that has been used for gene therapy. In the present study, the combined mechanistic effects of rAd-p53 and curcumin, a naturally occurring compound with previously reported anti-inflammatory, antioxidant and anti-cancer properties, were assessed in liver cancer cells, using HepG2 cells as the model cell line. The administration of either curcumin or rAd-p53 promoted apoptosis, suppressed epithelial-mesenchymal transition (EMT) and blocked G2/M phase progression in HepG2 cells, which were potentiated further when both agents were applied together. Combined rAd-p53 and curcumin treatment resulted in higher p53 (P<0.01) and p21 (P<0.01) expression compared with rAd-p53 or curcumin were added alone, suggesting an additive effect on TP53 expression. Additionally, curcumin and rAd-p53 were demonstrated to regulate the activation of mitogen-activated protein kinases (MAPKs) ERK1/2, p38 MAPK and JNK. These results indicated that the combination of rAd-p53 with curcumin synergistically potentiates apoptosis and inhibit EMT compared with either rAd-p53 or curcumin treatment alone via the regulation of TP53 regulation. Mechanistically, this effect on TP53 expression may involve the ERK1/2, p38 MAPK and JNK signaling pathways. The current study provides new insights that can potentially advance the development of therapeutic strategies for liver cancer treatment.

Carcinogenesis and Metastasis in Liver: Cell Physiological Basis

Hepatocellular carcinoma (HCC) incidence is rising. This paper summarises the current state of knowledge and recent discoveries in the cellular and physiological mechanisms leading to the development of liver cancer, especially HCC, and liver metastases. After reviewing normal hepatic cytoarchitecture and immunological characteristics, the paper addresses the pathophysiological factors that cause liver damage and predispose to neoplasia. Particular attention is given to chronic liver diseases, metabolic syndrome and the impact of altered gut microbiota, disrupted circadian rhythm and psychological stress. Improved knowledge of the multifactorial aetiology of HCC has important implications for the prevention and treatment of this cancer and of liver metastases in general.

Emergence of neural regulatory mechanisms in carcinogenesis

Emerging data indicate that the nervous system plays an important role in carcinogenesis. However, more studies are required to help further elucidate the mechanisms involved in the neural regulation of carcinogenesis. Some recent findings describing the neural regulatory mechanisms of action in prostate cancer, pancreatic cancer and hepatocellular carcinoma are discussed, with a focus on the sympathetic, parasympathetic, and sensory neuronal elements of the nervous system. Norepinephrine, which is released by the sympathetic nervous system and binds to the beta-adrenergic receptor, regulates cellular responses in both normal and tumor cells. It has also been shown that the destruction of sensory neurons can prevent or at least slow pancreatic cancer. Cortisol, the main stress hormone, is also discussed and how it could potentially be involved in hepatocellular carcinoma development. The importance of studying other signaling molecules in the nervous system, such as oxytocin and its receptor, the oxytocin receptor, and how they might be involved in carcinogenesis when aberrantly expressed is highlighted. This is an area of study which clearly needs further investigation. A clearer understanding of the detailed mechanisms of how the nervous system is involved in carcinogenesis could potentially aid in the identification of novel biomarkers and development of novel preventative and therapeutic strategies in various cancers.

Knockdown expression of MECR, a novel gene of mitochondrial FAS II inhibits growth and colony-formation, promotes apoptosis of hepatocelluar carcinoma cells

Mitochondrial trans-2-enoyl-CoA reductase (MECR) is a protein-coding gene, and the protein encoded by this gene is an oxidoreductase that catalyzes the last step in mitochondrial fatty acid synthesis (mtFASII). Numerous studies have shown disorder of lipid metabolism is closely related with malignance, especially in liver cancer. Through pre-experiment, we found that the expression of MECR gene was highly expressed in hepatocelluar carcinoma (HCC) cell lines in vitro. This suggests that the MECR gene may play a role of oncogene in HCC. Therefore, we conducted a preliminary experimental study on the role of MECR gene in HCC cells in vitro. Objective to explore whether the MECR gene can affect the malignant biological behavior of HCC. We selected HCC cell line BEL-7404 as experimental cell, which involves the highest expression of MECR in the pre-experiment. We constructed MECR knockdwon lentivirus vector, and then infected HCC cell lines to down-regulate MECR expression, and establish negative control group (NC). Through various experiments of cytology, our study showed that knockdown of MECR inhibited cell proliferation and colony formation, promoted apoptosis, and inhibited metastasis in HCC cell lines BEL-7404. MECR might serve as a novel gene therapeutic target for the treatment of HCC. Further study is needed to elucidate the signaling pathway through which MECR functions in HCC.

Mechanisms of hepatocellular carcinoma progression

Hepatocellular carcinoma (HCC) is the most common primary malignancy of the liver. It is the second leading cause of cancer-related deaths worldwide, with a very poor prognosis. In the United States, there has been only minimal improvement in the prognosis for HCC patients over the past 15 years. Details of the molecular mechanisms and other mechanisms of HCC progression remain unclear. Consequently, there is an urgent need for better understanding of these mechanisms. HCC is often diagnosed at advanced stages, and most patients will therefore need systemic therapy, with sorafenib being the most common at the present time. However, sorafenib therapy only minimally enhances patient survival. This review provides a summary of some of the known mechanisms that either cause HCC or contribute to its progression. Included in this review are the roles of viral hepatitis, non-viral hepatitis, chronic alcohol intake, genetic predisposition and congenital abnormalities, toxic exposures, and autoimmune diseases of the liver. Well-established molecular mechanisms of HCC progression such as epithelial-mesenchymal transition, tumor-stromal interactions and the tumor microenvironment, cancer stem cells, and senescence bypass are also discussed. Additionally, we discuss the roles of circulating tumor cells, immunomodulation, and neural regulation as potential new mechanisms of HCC progression. A better understanding of these mechanisms could have implications for the development of novel and more effective therapeutic and prognostic strategies, which are critically needed.

Correlation between CT features and liver function and p53 expression in hepatitis, cirrhosis and hepatocellular carcinoma

This study aimed to investigate the correlation between CT features and liver function and p53 expression in hepatitis, cirrhosis and hepatocellular carcinoma (HCC). Forty patients with HCC, 30 patients with cirrhosis and 30 patients with chronic hepatitis were enrolled between December, 2015 and December, 2016. At the same time, normal liver tissues collected from 30 patients with hepatic hemangioma were used as the normal control group. All the patients were scanned by CT. Average body surface area, left outer lobe and caudate lobe volume, and the proportions of left outer lobe and caudate lobe to the whole liver were calculated. Biochemical indexes of liver function were determined. The pathological tissues of all the subjects were analyzed. Compared with the control group, total liver volume of the HCC group was significantly reduced (P<0.05). Compared with the HCC group, the volume of the left outer lobe increased in the hepatitis group and the cirrhosis group. Compared with control group, caudate lobe volume increased significantly in the hepatitis group (P<0.05). Compared with the control group, the volume of the left outer lobe and the proportion of caudate lobe to the whole liver volume was significantly increased in all three groups (P<0.05). Liver function-related indicators in the HCC and cirrhosis groups were significantly different from those in the control group (P<0.05). The expression level of p53 in HCC was significantly higher than that in the control group (P<0.05). The accuracy of diagnosis by using both p53 and CT was higher than the use of p53 or CT alone. CT can accurately measure the volume of each lobe of the liver, and p53 has important clinical values in the diagnosis of liver diseases. Thus, the reasonable combination of the two can effectively improve the diagnostic accuracy.