The malignancy of liver cancer cells is increased by IL-4/ERK/AKT signaling axis activity triggered by irradiated endothelial cells

Association between pro-inflammatory diet and liver cancer risk: a systematic review and meta-analysis

OBJECTIVE

This systematic review aimed to investigate the association between dietary inflammatory potential and liver cancer to provide evidence regarding scientific dietary health education.

DESIGN

Systematic review and meta-analysis.

SETTING

A comprehensive literature review was conducted to identify case-control or cohort studies that involved dietary inflammation index (DII)/empirical dietary inflammation pattern (EDIP) and liver cancer in PubMed, EMBASE, Cochrane, and Web of Science databases. Using a combination of DII/EDIP and liver cancer as the search terms, the associations between DII/EDIP and liver cancer were then assessed.

PARTICIPANTS

Three case-control studies and two cohort studies were brought into the meta-analysis, with 225 713 enrolled participants.

RESULTS

Meta-analysis of categorical variables showed that DII/EDIP in the highest category increased the risk of liver cancer compared to DII/EDIP in the lowest category (relative risk (RR) = 2·35; 95 % CI 1·77, 3·13; P = 0·000) and with low heterogeneity across studies (I2 = 40·8 %, P = 0·119). Meta-analysis of continuous variables showed that significant positive association between liver cancer and DII/EDIP scores (RR = 1·24; 95 % CI 1·09, 1·40; P = 0·001), and no heterogeneity (I² = 0·0 %, P = 0·471). Stratified according to the study design, there was a significant positive association between liver cancer and DII/EDIP scores in both cohort studies (RR = 2·16; 95 % CI 1·51, 3·07; P = 0·000) and case-control studies (RR = 2·75; 95 % CI 1·71, 4·41; P = 0·000).

CONCLUSION

The higher the DII/EDIP score, the higher the risk of liver cancer. This finding may have prominent implications for the general population.

c-Jun-mediated JMJD6 restoration enhances resistance of liver cancer to radiotherapy through the IL-4-activated ERK pathway

Radiotherapy is widely used in the treatment of liver cancer, but the efficacy can be limited by radioresistance. In this study, we attempt to delineate the possible molecular mechanism of c-Jun-regulated Jumonji domain-containing protein 6/interleukin 4/extracellular signal-regulated kinase (JMJD6/IL-4/ERK) axis in radioresistance of liver cancer. The expression of c-Jun was quantified in liver cancer tissues and cell lines, and the results indicated that c-Jun was upregulated in liver cancer tissues and cells. We further illustrated the role of c-Jun following gain- and loss-of-function strategies in malignant phenotypes of liver cancer cells. It was established that c-Jun elevated JMJD6 expression and augmented the malignancy and aggressiveness of liver cancer cells. The in vivo effects of c-Jun on radioresistance in liver cancer were validated in nude mice, in response to IL-4 knockdown or the ERK pathway inhibitor, PD98059. In the presence of JMJD6 upregulation, the expression of IL-4 was elevated in mice with liver cancer, which enhanced the radiation resistance. Moreover, knockdown of IL-4 inactivated the ERK pathway, thereby reversing the radiation resistance caused by overexpressed JMJD6 in tumor-bearing mice. Taken together, c-Jun augments the radiation resistance in liver cancer by activating the ERK pathway through JMJD6-upregulated IL-4 transcription.

Anti-drug resistance, anti-inflammation, and anti-proliferation activities mediated by melatonin in doxorubicin-resistant hepatocellular carcinoma: in vitro investigations

Hepatocellular carcinoma (HCC) is the major life-threatening primary liver malignancy in both sexes all over the world. Unfortunately, the majority of patients are diagnosed at later stages because HCC does not elicit obvious symptoms during its early incidence. Consequently, most individuals escape the first-line HCC treatments and are treated with chemotherapy. Regrettably, the therapeutic outcomes for those patients are usually poor because of the development of multidrug resistance phenomena. Furthermore, most anti-HCC therapies cause severe undesired side effects that notably interfere with the life quality of such patients. Accordingly, there is an important need to search for an alternative therapeutic drug or adjuvant which is more efficient with safe or even minimal side effects for HCC treatment. Melatonin was recently reported to exert intrinsic antitumor activity in different cancers. However, the regulatory pathways underlying the antitumor activity of melatonin are poorly understood in resistant liver cells. Furthermore, a limited number of studies have addressed the therapeutic role of melatonin in HCC cells resistant to doxorubicin chemotherapy. In this study, we investigated the antitumor effects of melatonin in doxorubicin-resistant HepG2 cells and explored the regulatory pivotal targets underlying these effects. To achieve our aim, an MTT assay was used to calculate the 50% inhibitory concentration of melatonin and evaluate its antiproliferative effect on resistant cells. Additionally, qRT-PCR was used to quantify genes having a role in drug resistance phenotype (ABCB1, ABCC1, ABCC2, ABCC3, ABCC4, ABCC5, and ABCG2); apoptosis (caspases-3, and -7, Bcl2, Bax, and p53); anti-oxidation (NRF2); expression of melatonin receptors (MT1, MT2, and MT3); besides, programmed death receptor PD-1 gene. The active form of the caspase-3 enzyme was estimated by ELISA. A human inflammatory antibody membrane array was employed to quantify forty inflammatory factors expressed in treated cells. We observed that melatonin inhibited the proliferation of doxorubicin-resistant HepG2 cells in a dose-dependent manner after 24-h incubation time with a calculated IC₅₀ greater than 10 mM (13.4 mM), the expression levels of genes involved in drug resistance response (ABCB1, ABCC1, ABCC5, and ABCG2) were downregulated. Also, the expression of caspase-3, Caspase-7, NRF2, and p53 genes were expressed at higher levels as compared to control (DMSO-treated cells). An active form of caspase-3 was confirmed by ELISA. Moreover, the anti-inflammatory effect of melatonin was detected through the calculated fold change to control which was reduced for various mediators that have a role in the inflammation pathway. The current findings introduce melatonin as a promising anti-cancer treatment for human-resistant HCC which could be used in combination with current chemotherapeutic regimens to improve the outcome and reduce the developed multidrug resistance.

Radiotherapy-induced remodeling of the tumor microenvironment by stromal cells

Cancer cells reside amongst a complex milieu of stromal cells and structural features known as the tumor microenvironment. Often cancer cells divert and co-opt functions of stromal cells of the microenvironment to support tumor progression and treatment resistance. During therapy targeting cancer cells, the stromal cells of the microenvironment receive therapy to the same extent as cancer cells. Stromal cells therefore activate a variety of responses to the damage induced by these therapies, and some of those responses may support tumor progression and resistance. We review here the response of stromal cells to cancer therapy with a focus on radiotherapy in glioblastoma. We highlight the response of endothelial cells and the vasculature, macrophages and microglia, and astrocytes, as well as describing resulting changes in the extracellular matrix. We emphasize the complex interplay of these cellular factors in their dynamic responses. Finally, we discuss their resulting support of cancer cells in tumor progression and therapy resistance. Understanding the stromal cell response to therapy provides insight into complementary therapeutic targets to enhance tumor response to existing treatment options.

Context dependent role of p53 during the interaction of hepatocellular carcinoma and endothelial cells

BACKGROUND

During the progression of hepatocellular carcinoma (HCC), several angiogenic factors are overexpressed in the hepatic microenvironment, which play a critical role in governing the phenotype of the endothelial cells. Mutation in the p53 gene (TP53) is a common event in HCC that may dysregulate the angiogenic signals. However, their functional messages remain largely unexplored at the onset of metastasis.

METHODS

Role of p53 was studied by siRNA mediated silencing of p53 in HepG2 cells (WTp53), collecting and analyzing their conditioned medium, followed by indirect co-culture with endothelial cells (HUVECs). Gene and protein expression in HCC cells and endothelial cells was studied by RT-qPCR and western blotting respectively. β-catenin protein expression and localization were analyzed by immunocytochemistry.

RESULTS

We have studied a cell-to-cell interaction model to investigate the crosstalk of endothelial and hepatoma cells by either knocking down p53 or by using p53 null low metastatic HCC cell line. In the absence of p53, the HCC cells influence the migration and vascular network formation of endothelial cells through paracrine signaling of VEGF. Secretory VEGF activated the VEGF receptor-2 along with the survival signaling in endothelial cells. However, the β-catenin signal is upregulated in endothelial cells only during interaction with metastatic set up irrespective of absence and presence of p53, indicating context-dependent participation of p53 during communication between hepatoma cells and endothelial cells.

CONCLUSION

This study highlights that the role of p53 on cellular responses during interaction of hepatocellular carcinoma and endothelial cells is distinct to cell types and context.

The role of long non-coding RNA FGD5-AS1 in cancer

Long noncoding RNAs (lncRNAs) refers to a class of RNAs that have at least 200 nucleotides and do not encode proteins, and the relationship between lncRNA and cancer has recently attracted considerable research attention. The lncRNA FGD5-AS1 is a newly discovered lncRNA with a length of 3772 nucleotides. Studies have found that FGD5-AS1 is abnormally highly expressed in many cancer tissues and was closely related to the lymph node metastasis, tumor invasion, survival time, and recurrence rate of various cancers. Mechanistic analyses show that FGD5-AS1 can stabilize mRNA expression by sponging miRNA, which not only induces cancer cell proliferation, metastasis, invasion, and chemoresistance in vitro, but also promotes tumor growth and metastasis in vivo. In addition, FGD5-AS1 can serve as a diagnostic or prognostic marker for a variety of cancers. This review demonstrates the clinical significance of FGD5-AS1 in human cancer and its role in tumorigenesis and tumor progression.

Loss of Interleukin-13-Receptor-Alpha-1 Induces Apoptosis and Promotes EMT in Pancreatic Cancer

In search of new therapies for pancreatic cancer, cytokine pathways have attracted increasing interest in recent years. Cytokines play a vital role in the crosstalk between tumour cells and the tumour microenvironment. The related inflammatory cytokines IL-4 and IL-13 can regularly be detected at increased levels in the microenvironment of pancreatic cancer. They share a receptor heterodimer consisting of IL-4Rα and IL-13Rα1. While IL-4Rα induces a more oncogenic phenotype, the role of IL-13Rα1 was yet to be determined. ShRNA-based knockdown of IL-13Rα1 was performed in Capan-1 and MIA PaCa-2. We assessed cell growth and migratory capacities under the influence of IL-13Rα1. Pathway alterations were detected by immunoblot analysis. We now have demonstrated that the loss of IL-13Rα1 induces apoptosis in pancreatic cancer cells. This was associated with an epithelial-to-mesenchymal transition. Loss of IL-13Rα1 also abolished the effects of exogenous IL-4 and IL-13 stimulation. Interestingly, in wild type cells, cytokine stimulation caused a similar increase in migratory capacities as after IL-13Rα1 knockdown. Overall, our results indicate the vital role of IL-13Rα1 in the progression of pancreatic cancer. The differential expression of IL-4Rα and IL-13Rα1 has to be taken into account when considering a cytokine-targeted therapy in pancreatic cancer.

Microenvironment of Cancer Stem Cells

Microenvironment of cancer stem cells (CSCs) consists of a variety of cells and inter-cellular matrix and communications of the components. The microenvironment of CSCs maintains the stemness feature of the CSCs. Several cell types which communicate each other via signaling molecules surrounding CSCs are main factors of the CSC microenvironment. A key question is "What kind of information the cells exchange in the CSC microenvironment?" to reveal the microenvironment and CSC features. Components and molecular markers of CSC microenvironment, signaling cross-talks in CSC microenvironment, and targeting CSC microenvironment are focused in this review.

Reconciling two opposing effects of radiation therapy: stimulation of cancer cell invasion and activation of anti-cancer immunity

PURPOSE

The damage caused by radiation therapy to cancerous and normal cells inevitably leads to changes in the secretome profile of pro and anti-inflammatory mediators. The inflammatory response depends on the dose of radiation and its fractionation, while the inherent radiosensitivity of each patient dictates the intensity and types of adverse reactions. This review will present an overview of two apparently opposite reactions that may occur after radiation treatment: induction of an antitumor immune response and a protumoral response. Emphasis is placed on the molecular and cellular mechanisms involved.

CONCLUSIONS

By understanding how radiation changes the balance between anti- and protumoral effects, these forces can be manipulated to optimize radiation oncology treatments.

Involvement of IL-4, IL-13 and Their Receptors in Pancreatic Cancer

Interleukin (IL)-4 and IL-13 are known as pleiotropic Th2 cytokines with a wide range of biological properties and functions especially in immune responses. In addition, increasing activities have also been determined in oncogenesis and tumor progression of several malignancies. It is now generally accepted that IL-4 and IL-13 can exert effects on epithelial tumor cells through corresponding receptors. Type II IL-4 receptor (IL-4Rα/IL-13Rα1), predominantly expressed in non-hematopoietic cells, is identified to be the main target for both IL-4 and IL-13 in tumors. Moreover, IL-13 can also signal by binding to the IL-13Rα2 receptor. Structural similarity due to the use of the same receptor complex generated in response to IL-4/IL-13 results in overlapping but also distinct signaling pathways and functions. The aim of this review was to summarize knowledge about IL-4 and IL-13 and their receptors in pancreatic cancer in order understand the implication of IL-4 and IL-13 and their receptors for pancreatic tumorigenesis and progression and for developing possible new diagnostic and therapeutic targets.

Radiotherapy targeting cancer stem cells "awakens" them to induce tumour relapse and metastasis in oral cancer

Radiotherapy is one of the most common treatments for oral cancer. However, in the clinic, recurrence and metastasis of oral cancer occur after radiotherapy, and the underlying mechanism remains unclear. Cancer stem cells (CSCs), considered the “seeds” of cancer, have been confirmed to be in a quiescent state in most established tumours, with their innate radioresistance helping them survive more easily when exposed to radiation than differentiated cancer cells. There is increasing evidence that CSCs play an important role in recurrence and metastasis post-radiotherapy in many cancers. However, little is known about how oral CSCs cause tumour recurrence and metastasis post-radiotherapy. In this review article, we will first summarise methods for the identification of oral CSCs and then focus on the characteristics of a CSC subpopulation induced by radiation, hereafter referred to as “awakened” CSCs, to highlight their response to radiotherapy and potential role in tumour recurrence and metastasis post-radiotherapy as well as potential therapeutics targeting CSCs. In addition, we explore potential therapeutic strategies targeting these “awakened” CSCs to solve the serious clinical challenges of recurrence and metastasis in oral cancer after radiotherapy.

miR-328-3p overexpression attenuates the malignant proliferation and invasion of liver cancer via targeting Endoplasmic Reticulum Metallo Protease 1 to inhibit AKT phosphorylation

Background

Liver cancer is one of the most common cancers worldwide. microRNAs (miRNAs) have been recognized as minimally invasive prognostic markers for distinct types of cancer. This study evaluates the mitigation role of miR-328-3p on liver cancer in vitro and in vivo.

Methods

Liver cancer cell line Huh-7 and HepG2 were used for in vitro experiments. Compared with the control group, miR-328-3p overexpression inhibited the proliferation, invasion, and promoted apoptosis of Huh-7 cells. miR-328-3p and endoplasmic reticulum metalloprotease 1 (ERMP1) had an excellent targeting relationship. Compared with the pcDNA-ERMP1 transfection group, the ratios of p-PI3K/PI3K, p-AKT/AKT, and p-mTOR/mTOR in miR-328-3p mimic and pcDNA-ERMP1 co-transfection group were significantly decreased. Animal models were set up using four-week-old immunodeficient BABL/c female nude mice. Huh-7 cells transfected with lentivirus holding miR-328-3p or empty vector were injected into the right dorsal side of BABL/c nude mice, respectively. Tumor volume was measured every five days. After one month, animals were sacrificed, xenograft tumors were dissected and weighed for RT-PCR and immunohistochemical assays.

Results

Compared with control group, miR-328-3p overexpression significantly inhibited tumor weight (0.46±0.07 vs. 0.11±0.05 g, P<0.05) and tumor volume (1876±321 vs. 543±168 mm³, P<0.05) after thirty days. miR-328-3p overexpression significantly downregulated the percentage of Ki67 positive cells, N-cadherin positive cells and vimentin positive cells.

Conclusions

These findings suggested that miR-328-3p could be a new treatment or a novel marker for liver cancer prognosis.