The role of alpha-fetoprotein in the tumor microenvironment of hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is a prevalent malignant cancer worldwide, characterized by high morbidity and mortality rates. Alpha-fetoprotein (AFP) is a glycoprotein synthesized by the liver and yolk sac during fetal development. However, the serum levels of AFP exhibit a significant correlation with the onset and progression of HCC in adults. Extensive research has demonstrated that the tumor microenvironment (TME) plays a crucial role in the malignant transformation of HCC, and AFP is a key factor in the TME, promoting HCC development. The objective of this review was to analyze the existing knowledge regarding the role of AFP in the TME. Specifically, this review focused on the effect of AFP on various cells in the TME, tumor immune evasion, and clinical application of AFP in the diagnosis and treatment of HCC. These findings offer valuable insights into the clinical treatment of HCC.

Structural characteristics of alpha-fetoprotein, including N-glycosylation, metal ion and fatty acid binding sites.

Alpha-fetoprotein (AFP), a serum glycoprotein, is expressed during embryonic development and the pathogenesis of liver cancer. It serves as a clinical tumor marker, function as a carcinogen, immune suppressor, and transport vehicle; but the detailed AFP structural information has not yet been reported. In this study, we used single-particle cryo-electron microscopy(cryo-EM) to analyze the structure of the recombinant AFP obtained a 3.31 Å cryo-EM structure and built an atomic model of AFP. We observed and identified certain structural features of AFP, including N-glycosylation at Asn251, four natural fatty acids bound to distinct domains, and the coordination of metal ions by residues His22, His264, His268, and Asp280. Furthermore, we compared the structural similarities and differences between AFP and human serum albumin. The elucidation of AFP's structural characteristics not only contributes to a deeper understanding of its functional mechanisms, but also provides a structural basis for developing AFP-based drug vehicles.

The diagnostic, prognostic, drug sensitivity and ceRNA internet of PPP4R1 in liver hepatocellular carcinoma (LIHC).

Background: Recent studies have reported a role of protein phosphatase 4 regulatory subunit 1 (PPP4R1) in cancer development. However, its expression, diagnostic significance, prognostic value and biological function in liver hepatocellular carcinoma (LIHC) are not known. Methods: The expression level of PPP4R1 in pan-cancer was evaluated by analyzing publicly accessible data from the University of California Santa Cruz (UCSC) Xena database. The diagnostic value of PPP4R1 for tumors was assessed using receiver operating characteristic (ROC) curves, whereas the impact of PPP4R1 on tumor prognosis was determined using Kaplan-Meier survival curves, and a prognostic model for LIHC was established using cox regression analysis. In addition, analysis of the correlation between PPP4R1 and anti-cancer drugs using Spearman's correlation coefficient was carried out. Four databases, miRWalk (mRNA-miRNA interactions), MicroT-CDS (mRNA-miRNA interactions), LncBase (miRNA-lncRNA interactions) and Encyclopedia of RNA Interactomes (ENCORI), were used to predict the competitive endogenous RNA (ceRNA) regulatory network of PPP4R1. Finally, the expression of PPP4R1 protein levels was verified using experiments. Results: The findings indicated that the PPP4R1 expression level in cancerous tissues was notably greater than in adjacent tissues (P<0.05). PPP4R1 showed diagnostic significance for 14 tumors based on the ROC curves results area under the curve >0.7. Furthermore, the Kaplan-Meier survival plots demonstrated that PPP4R1 exhibited prognostic significance for all five tumors (P<0.05). According to the cox regression analysis, LIHC patients' prognosis was independently influenced by pathological stage, M stage, and PPP4R1 (P<0.05). The drug sensitivity analysis revealed a positive correlation between the expression level of PPP4R1 and the half maximal inhibitory concentration (IC50) of fludarabine. Additionally, the ceRNA network prediction indicated that the FGD5 antisense RNA 1 (FGD5-AS1)-hsa-miR-22-3p-PPP4R1 ceRNA network could potentially contribute to the progression of LIHC. The experimental results showed that the expression level of PPP4R1 protein was higher in cancer tissues than in paracancerous tissues. Conclusions: PPP4R1 has diagnostic value in most cancers, and high expression of PPP4R1 is associated with poor prognosis, drug resistance and natural killer cell-mediated toxicity, particularly in LIHC. Therefore, PPP4R1 may be a prognostic biomarker and a potential target for immunotherapy in LIHC.

α-Conotoxin recombinant protein ImI-AFP3 efficiently inhibits the growth and migration of lung cancer cells.

α-Conotoxin ImI is a selective antagonist of alpha7 nicotinic acetylcholine receptor (α7 nAChR) that is involved in cancer development. Human alpha fetoprotein domain 3 (AFP3) is a prototype of anticancer agents. In an effort to design drugs for anticancer treatments, we fused the ImI peptide to AFP3 as a fusion protein for testing. The fusion protein (ImI-AFP3) was highly expressed in the insect Bac-to-Bac system. The purified fusion protein was found to have improved anticancer activity and synergized with the drug gefitinib to inhibit the growth and migration of A549 and NCI-H1299 lung cancer cells. Our data have demonstrated that the recombinant protein ImI-AFP3 is a promising candidate for drug development to suppress lung cancer cell growth, especially to suppress hepatoid adenocarcinoma of the lung (HAL) cell growth.

Glucose metabolism reprogramming promotes immune escape of hepatocellular carcinoma cells.

Hepatocellular carcinoma (HCC) is a complex process that plays an important role in its progression. Abnormal glucose metabolism in HCC cells can meet the nutrients required for the occurrence and development of liver cancer, better adapt to changes in the surrounding microenvironment, and escape the attack of the immune system on the tumor. There is a close relationship between reprogramming of glucose metabolism and immune escape. This article reviews the current status and progress of glucose metabolism reprogramming in promoting immune escape in liver cancer, aiming to provide new strategies for clinical immunotherapy of liver cancer.

Alpha fetoprotein promotes polarization of macrophages towards M2-like phenotype and inhibits macrophages to phagocytize hepatoma cells.

Alpha-fetoprotein(AFP) is a cancer biomarker for the diagnosis of hepatocellular carcinoma(HCC); however, its role in macrophage polarization and phagocytosis remains unclear. In the present study, we explored the correlation between AFP regulation of macrophage function and the possible regulatory mechanisms. Human mononuclear leukemia cells (THP-1) and monocytes from healthy donors were used to analyze the effect of AFP on the macrophages' phenotype and phagocytosis. THP-1 cells and healthy human donor-derived monocytes were polarized into M0 macrophages induced by phorbol ester (PMA), and M0 macrophages were polarized into M1 macrophages induced by lipopolysaccharide(LPS) and interferon-γ(IFN-γ). Interleukin-4(IL-4) and interleukin-13(IL-13) were used to induce M0 macrophage polarization into M2 macrophages. Tumor-derived AFP(tAFP) stimulated M0 macrophage polarization into M2 macrophages and inhibited M1 macrophages to phagocytize HCC cells. The role of AFP in promoting macrophage polarization into M2 macrophages and inhibiting the M1 macrophages to phagocytize HCC cells may be involved in activating the PI3K/Akt signaling pathway. AFP could also enhanced the migration ability of macrophages and inhibited the apoptosis of HCC cells when co-cultured with M1-like macrophages. AFP is a pivotal cytokine that inhibits macrophages to phagocytize HCC cells.

Tumor-associated macrophage polarization in the inflammatory tumor microenvironment.

The chronic inflammation of tumor continues to recruit TAMs (tumor-associated macrophages) to the TME (tumor microenvironment) and promote polarization. Pro-inflammatory signals polarize macrophages to the M1 phenotype to enhance inflammation against pathogens. Tumor inflammatory development changes the pro-inflammatory response to an anti-inflammatory response, resulting in the alteration of macrophages from M1 to M2 to promote tumor progression. Additionally, hypoxia activates HIF (hypoxia-inducible factors) in the TME, which reprograms macrophages to the M2 phenotype to support tumor development. Here, we discuss the factors that drive phenotypic changes in TAMs in the inflammatory TME, which will help in the development of cancer immunotherapy of macrophages.

Uniform thin ice on ultraflat graphene for high-resolution cryo-EM.

Cryo-electron microscopy (cryo-EM) visualizes the atomic structure of macromolecules that are embedded in vitrified thin ice at their close-to-native state. However, the homogeneity of ice thickness, a key factor to ensure high image quality, is poorly controlled during specimen preparation and has become one of the main challenges for high-resolution cryo-EM. Here we found that the uniformity of thin ice relies on the surface flatness of the supporting film, and developed a method to use ultraflat graphene (UFG) as the support for cryo-EM specimen preparation to achieve better control of vitreous ice thickness. We show that the uniform thin ice on UFG improves the image quality of vitrified specimens. Using such a method we successfully determined the three-dimensional structures of hemoglobin (64 kDa), α-fetoprotein (67 kDa) with no symmetry, and streptavidin (52 kDa) at a resolution of 3.5 Å, 2.6 Å and 2.2 Å, respectively. Furthermore, our results demonstrate the potential of UFG for the fields of cryo-electron tomography and structure-based drug discovery.

α-Fetoprotein fragment synergizes with sorafenib to inhibit hepatoma cell growth and migration and promote the apoptosis.

Alpha fetoprotein (AFP) is associated with hepatocellular carcinoma (HCC) by stimulating the proliferation, metastasis and drug resistance. The application of AFP fragments to inhibit the malignant behaviours induced by AFP is a new strategy for the treatment of HCC. In an effort to design, screen and discover drugs, we attempted to express different human AFP fragments (AFP220-609 , AFP390-609 and AFP460-609 ) in a Bac-to-Bac system. We found that the AFP390-609 fragment was highly expressed in the system. Then, we assessed the bioactivity of the fragment in the human liver cancer cell line Bel7402, and the results indicated that the AFP fragment synergized with sorafenib to inhibit the hepatoma cell growth and migration and promote the apoptosis. This study provides a method to produce significant AFP fragments to screen AFP inhibitors for use in HCC therapy.

Erratum: Hepatitis B Virus X Protein Driven Alpha Fetoprotein Expression to Promote Malignant Behaviors of Normal Liver Cells and Hepatoma Cells: Erratum.

[This corrects the article DOI: 10.7150/jca.13628.].

[Corrigendum] SCF increases cardiac stem cell migration through PI3K/AKT and MMP­2/­9 signaling.

Following the publication of this article, the authors have realized that they mistakenly used the total AKT blot featured in Fig. 4A for the GAPDH blot in Fig. 3B on p. 116. The corrected version of Fig. 3, featured the correct data for the GAPDH experiment, is shown opposite. The authors regret that this error was not picked up upon before the paper was sent to press, and thank the Editor of International Journal of Molecular Medicine for allowing them the opportunity to publish a corrigendum. The error did not affect either the results or the conclusions reported in the study, and all the authors agree to this corrigendum. Furthermore, they regret any inconvenience caused to the readership. [the original article was published in International Journal of Molecular Medicine 34: 112­118, 2014; DOI: 10.3892/ijmm.2014.1773].

Dynamic contrast-enhanced MRI predicts PTEN protein expression which can function as a prognostic measure of progression-free survival in NPC patients.

OBJECTIVES: The objective of our study was to investigate whether a phosphatase and tensin homolog deleted on chromosome 10 (PTEN) expression was associated with dynamic contrast-enhanced MRI (DCE-MRI) parameters and prognosis in nasopharyngeal carcinoma (NPC). METHODS: Two-hundred-and-forty-five (245) patients with NPC who underwent pretreatment biopsy, expression of PTEN detected by immunohistochemistry of biopsy, and radical intensity-modulated radiation therapy (IMRT) with or without chemotherapy were included. Tumor segmentations were delineated on pretreatment MRI manually. The pharmacokinetic parameters (Ktrans, Kep, Ve, and Vp) derived from dynamic contrast-enhanced MRI (DCE-MRI) using the extended Toft's model within the tumor segmentations were estimated. The following demographics and clinical features were assessed and correlated against each other: gender, age, TNM stage, clinical-stage, Epstein-Barr virus (EBV), pathological type, progression-free survival (PFS), and prognosis status. DCE parameter evaluation and clinical feature comparison between the PTEN positive and negative groups were performed and correlation between PTEN expression with the PFS and prognosis status using Cox regression for survival analysis were assessed. RESULTS: A significantly lower Ktrans and Kep were found in NPC tumors in PTEN negative patients than in PTEN positive patients. Ktrans performed better than Kep in detecting PTEN expression with the ROC AUC of 0.752. PTEN negative was associated with later TNM stage, later clinical-stage, shorter PFS, and worse prognosis. Moreover, N stage, pathological type, Kep, and prognostic status can be considered as independent variables in discrimination of PTEN negative expression in NPCs. CONCLUSIONS: PTEN negative indicated a shorter PFS and worse prognosis than PTEN positive in NPC patients. Ktrans and Kep derived from DCE-MRI, which yielded reliable capability, may be considered as potential imaging markers that are correlated with PTEN expression and could be used to predict PTEN expression noninvasively. Combined radiological and clinical features can improve the performance of the classification of PTEN expression.

AFP-Inhibiting Fragments for Drug Delivery: The Promise and Challenges of Targeting Therapeutics to Cancers.

Alpha fetoprotein (AFP) plays a key role in stimulating the growth, metastasis and drug resistance of hepatocellular carcinoma (HCC). AFP is an important target molecule in the treatment of HCC. The application of AFP-derived peptides, AFP fragments and recombinant AFP (AFP-inhibiting fragments, AIFs) to inhibit the binding of AFP to intracellular proteins or its receptors is the basis of a new strategy for the treatment of HCC and other cancers. In addition, AIFs can be combined with drugs and delivery agents to target treatments to cancer. AIFs conjugated to anticancer drugs not only destroy cancer cells with these drugs but also activate immune cells to kill cancer cells. Furthermore, AIF delivery of drugs relieves immunosuppression and enhances chemotherapy effects. The synergism of immunotherapy and targeted chemotherapy is expected to play an important role in enhancing the treatment effect of patients with cancer. AIF delivery of drugs will be an available strategy for the targeted treatment of cancer in the future.

Alpha-Fetoprotein Binding Mucin and Scavenger Receptors: An Available Bio-Target for Treating Cancer.

Alpha-fetoprotein (AFP) entrance into cancer cells is mediated by AFP receptors (AFPRs) and exerts malignant effects. Therefore, understanding the structure of AFPRs will facilitate the development of rational approaches for vaccine design, drug delivery, antagonizing immune suppression and diagnostic imaging to treat cancer effectively. Throughout the last three decades, the identification of universal receptors for AFP has failed due to their complex carbohydrate polymer structures. Here, we focused on the two types of binding proteins or receptors that may serve as AFPRs, namely, the A) mucin receptors family, and B) the scavenger family. We presented an informative review with detailed descriptions of the signal transduction, cross-talk, and interplay of various transcription factors which highlight the downstream events following AFP binding to mucin or scavenger receptors. We mainly explored the underlying mechanisms involved mucin or scavenger receptors that interact with AFP, provide more evidence to support these receptors as tumor AFPRs, and establish a theoretical basis for targeting therapy of cancer.

IL-6/STAT3 Is a Promising Therapeutic Target for Hepatocellular Carcinoma.

Hepatocellular carcinoma (HCC) is a common malignant tumor of which the occurrence and development, the tumorigenicity of HCC is involving in multistep and multifactor interactions. Interleukin-6 (IL-6), a multifunctional inflammatory cytokine, has increased expression in HCC patients and is closely related to the occurrence of HCC and prognosis. IL-6 plays a role by binding to the IL-6 receptor (IL-6R) and then triggering the Janus kinase (JAK) associated with the receptor, stimulating phosphorylation and activating signal transducer and activator of transcription 3 (STAT3) to initiate downstream signals, participating in the processes of anti-apoptosis, angiogenesis, proliferation, invasion, metastasis, and drug resistance of cancer cells. IL-6/STAT3 signal axes elicit an immunosuppressive in tumor microenvironment, it is important to therapy HCC by blocking the IL-6/STAT3 signaling pathway. Recent, some inhibitors of IL-6/STAT3 have been development, such as S31-201 or IL-6 neutralizing monoclonal antibody (IL-6 mAb), Madindoline A (Inhibits the dimerization of IL-6/IL-6R/gpl30 trimeric complexes), C188-9 and Curcumin (Inhibits STAT3 phosphorylation), etc. for treatment of cancers. Overall, consideration of the IL-6/STAT3 signaling pathway, and its role in the carcinogenesis and progression of HCC will contribute to the development of potential drugs for targeting treatment of liver cancer.

Role of Alpha-Fetoprotein in Hepatocellular Carcinoma Drug Resistance.

Hepatocellular carcinoma (HCC) is a major type of primary liver cancer and a major cause of cancer-related deaths worldwide because of its high recurrence rate and poor prognosis. Surgical resection is currently the major treatment measure for patients in the early and middle stages of the disease. Because due to late diagnosis, most patients already miss the opportunity for surgery upon disease confirmation, conservative chemotherapy (drug treatment) remains an important method of comprehensive treatment for patients with middle- and late-stage liver cancer. However, multidrug resistance (MDR) in patients with HCC severely reduces the treatment effect and is an important obstacle to chemotherapeutic success. Alpha-fetoprotein (AFP) is an important biomarker for the diagnosis of HCC. The serum expression levels of AFP in many patients with HCC are increased, and a persistently increased AFP level is a risk factor for HCC progression. Many studies have indicated that AFP functions as an immune suppressor, and AFP can promote malignant transformation during HCC development and might be involved in the process of MDR in patients with liver cancer. This review describes drug resistance mechanisms during HCC drug treatment and reviews the relationship between the mechanism of AFP in HCC development and progression and HCC drug resistance.

Exosome-Delivered LncHEIH Promotes Gastric Cancer Progression by Upregulating EZH2 and Stimulating Methylation of the GSDME Promoter.

Gastric cancer is the third leading cause of cancer-related deaths worldwide and is characterized by poor survival and high recurrence rates. Long non-coding RNAs (lncRNAs) have gained considerable attention in recent years as prognostic markers and gene regulators in various cancers. Here, we found that lncHEIH was upregulated in gastric cancer tissues and cell lines and positively correlated with high expression levels of EZH2. Mechanistically, the lncHEIH-EZH2 axis could promote the progression of gastric cancer. In addition, lncHEIH encapsulated in exosomes was released by gastric cancer cells and then absorbed by normal gastric cells. The uptake of lncHEIH resulted in the upregulation of EZH2, which inhibited the expression of the tumor suppressor GSDME by methylation of the GSDME promoter, promoting the malignant transformation of normal gastric cells. Overall, lncHEIH promotes gastric cancer progression by upregulating the expression of EZH2 and reducing the expression of GSDME in normal cells to induce malignant cell proliferation and migration, indicating its potential as a target in gastric cancer therapy.

Overexpression of GATA5 Stimulates Paclitaxel to Inhibit Malignant Behaviors of Hepatocellular Carcinoma Cells.

OBJECTIVE: Explore the effect of GATA5 expression on Paclitaxel inhibiting growth of hepatocellular carcinoma (HCC) cells. MATERIALS AND METHODS: In the experimental study, HCC cell lines (HLE, Bel7402 and PLC/PRF/5) were treated with different concentrations of Paclitaxel (5-20 mg/ml) for 24 hours. HLE cells were transfected with GATA5-siRNA vector, while Bel7402 and PLC/PRF/5 cells were transfected with overexpressed GATA5 vector for 24 hours, followed by treatment of the cells with Paclitaxel (10 mg/ml) for 24 hours and subsequently 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay to detect growth of HCC cells. Soft agar cultured was used to analyze formation of colony. Apoptosis of HCC cells were detected by Flow cytometer. Migration of HCC cells was observed by trawell assays. Western blotting and laser confocal microscopy were utilized to detect expression and location of the proteins. RESULTS: Inhibiting expression of GATA5 reduced sensitivity of HLE cells to Paclitaxel, while overexpression of GATA5 increased sensitivity of Bel7402 cells and PLC/PRF/5 cells to Paclitaxel. Overexpression of GATA5 played a role in stimulating Paclitaxel to inhibit growth, colony formation and migration, as well as enhance apoptosis in HCC cells. Overexpression of GATA5 also promoted Paclitaxel to inhibit expression of reprogramming genes, such as Nanog, EpCAM, c-Myc and Sox2 in Bel7402 and PLC/PRF/5 cells. Inhibited expression of GATA5 led to enhancement of the expression of CD44 and CD133, in HLE cells. Overexpression of GATA5 was not only alone but also synergized with Paclitaxel to inhibit expression of CD44 and CD133 in Bel7402 or PLC/PRF/5 cells. CONCLUSION: Overexpression of GATA5 played a role in enhancing Paclitaxel to inhibit the malignant behaviors of HCC cells. It was involved in suppressing expression of the reprogramming genes and stemness markers. Targeting GATA5 is an available strategy for applying paclitaxel to therapy of patients with HCC.

Effects of alpha-fetoprotein on the occurrence and progression of hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors in the world. Alpha-fetoprotein (AFP) is considered as a diagnostic and prognostic tumorous marker for HCC, and up to 70% of HCC patients showed elevated serum levels of AFP. In the past two decades, evidences have shown that AFP not only is a tumorous biomarker for diagnosing HCC, but also plays a very complicated role in regulating proliferation, apoptosis, and autophagy and inhibiting the immune response of cells. Because AFP is significantly elevated during hepatocarcinogenesis, the role of AFP in the development of HCC is a scientific problem worthy of further exploration. In this review, we reviewed the effects of AFP on hepatocyte malignant transformation and the underlying mechanisms involved in the progression of HCC.

Ropivacaine promotes apoptosis of hepatocellular carcinoma cells through damaging mitochondria and activating caspase-3 activity.

BACKGROUND: Recent evidences indicated that some local anaesthetic agents played a role in inhibiting the proliferation of cancer cells; Whether ropivacaine is able to promote apoptosis of hepatocellular carcinoma (HCC) cells is still unclear. The aim of this study was to investigate the effect of ropivacaine on the apoptosis of HCC cells. METHODS: In the present study, we treated the HCC cell lines, Bel7402 and HLE with ropivacaine. MTT, DAPI stain, trypan blue exclusion dye assay, flow cytometry, electron microscopy, computational simulation, laser confocal microscope, Western blotting, and enzyme activity analysis of caspase-3 were applied to detect the growth and apoptosis of HCC cells and to explore the role mechanism of ropivacaine. RESULTS: Ropivacaine was able to inhibit proliferation and promote apoptosis of HCC cells in a dose- and time-dependent manner. Ropivacaine also has a trait to inhibit the migration of HCC cells; ropivacaine damaged the mitochondria of HCC cells. The results also indicated that ropivacaine was able to interact with caspase-3, promote cytoplasmic caspase-3 migration into the nucleus, stimulate cleavage of caspase-3 and PARP-1, caspase-9 proteins, inhibit the expression of Bcl-2, promote expression of Apaf-1 and mitochondria release cytochrome C, and activate the activity of caspase-3. CONCLUSIONS: Ropivacaine has a novel role in promoting apoptosis of HCC cells; The role mechanism of ropivacaine maybe involve in damaging the function of mitochondria and activating the caspase-3 signalling pathway in HCC cells. Our findings provide novel insights into the local anaesthetic agents in the therapy of HCC patients.