Our aims were to investigate and establish simple and reliable implanted hepatocellular carcinoma (HCC) models in Wistar rats. Concentrated suspensions of CBRH-7919 cancer cell lines were injected subcutaneously into the scapular regions of nude mice. The developing tumor tissues were then implanted into the livers of 45 adult Wistar rats. Dexamethasone (2.5 mg/day) was injected intramuscularly daily for 1 week preoperatively and 2 weeks postoperatively. After 4 weeks of implantation, ultrasonography and nuclear magnetic resonance imaging (MRI) were performed to identify model rats with liver tumor growth and to analyze the growth and characteristics of the tumors. Five of these model rats were then sacrificed, and the tumors were removed from the liver for pathological examination. Three rats died during the operation; among the remaining 42 rats, 36 possessed a total of 43 liver tumors. The success rate of tumor implantation was 85.7 % (36/42), and the diameters of the tumors ranged from 5 to 10 mm. All tumor specimens were confirmed to be HCC by pathological examination. This study provides a new approach for establishing implanted HCC models in Wistar rats, which can be used for studying numerous biological features of HCC.
The underlying molecular pathogenesis in hepatocellular carcinoma remains poorly understood. The transcription factor MEF2D promotes survival in various cell types and it seems to function as an oncogene in leukemia. However, its potential contributions to solid cancers have not been explored. In this study, we investigated MEF2D expression and function in hepatocellular carcinoma, finding that MEF2D elevation in hepatocellular carcinoma clinical specimens was associated with poor prognosis. MEF2D-positive primary hepatocellular carcinoma cells displayed a faster proliferation rate compared with MEF2D-negative cells, and silencing or promoting MEF2D expression in these settings limited or accelerated cell proliferation, respectively. Notably, MEF2D-silencing abolished hepatocellular carcinoma tumorigenicity in mouse xenograft models. Mechanistic investigations revealed that MEF2D-silencing triggered G2-M arrest in a manner associated with direct downregulation of the cell-cycle regulatory genes RPRM, GADD45A, GADD45B, and CDKN1A. Furthermore, we identified MEF2D as an authentic target of miR-122, the reduced expression of which in hepatocellular carcinoma may be responsible for MEF2D upregulation. Together, our results identify MEF2D as a candidate oncogene in hepatocellular carcinoma and a potential target for hepatocellular carcinoma therapy.
The brown tumor of the skeletal system is mainly caused by hyperparathyroidism (HPT), and HPT is divided into three categories according to its causes: primary, secondary and tertiary HPT. The secondary HPT patients with brown tumor caused by chronic renal insufficiency are rarely reported. The tumor occurs mostly in the bones such as metacarpals, phalanges, skull, pelvis, clavicle, ribs, femur and spine. We reported two cases of juxtacortical brown tumor in patients with HPT secondary to chronic renal insufficiency which has never been reported previously.
Understanding molecular mechanisms in self-renewal of cancer stem cells (CSCs) is important for finding novel target in therapy of cancer. In this study, we explored potential effects of histone deacetylase (HDAC) on liver CSCs. Our data showed that HDAC inhibitors suppressed self-renewal and induced differentiation of liver CSCs. Furthermore, we demonstrated that HDAC3 was selectively expressed in liver CSCs and participated in self-renewal of liver CSCs via regulating expression of pluripotency factors. Overexpression of HDAC3 was associated with poor outcome of liver cancer. HDAC inhibitors could render liver CSCs sensitive to sorafenib. Taken together, our data suggest that HDAC3 plays a critical role in regulating self-renewal of liver CSCs.
High invasion and metastasis are the primary factors causing poor prognosis of patients with hepatocellular carcinoma (HCC). However, the molecular mechanisms underlying these biological behaviors have not been completely elucidated. In this study, we investigate the molecular mechanism by which hypoxia promotes HCC invasion and metastasis through inducing epithelial-mesenchymal transition (EMT).
It has been demonstrated that numerous microRNAs (miRNAs) have potent tumor-suppressing effects on a variety of cancers, implicating a possible application of miRNA in tumor therapy. Oncolytic adenovirus is a suitable vector to deliver tumor suppressor genes for treatment of cancers. However, it remains unknown whether co-expression of tumor suppressor genes and miRNAs can contribute to a more potent antitumor capacity within an oncolytic adenovirus delivery system. In this study, we found that expression of miRNA-34a was reduced in hepatocellular carcinoma (HCC), and the reduced expression of miRNA-34a was associated with worse outcome of HCC patients. Thus, we developed an oncolytic adenoviral vector, AdCN205, to co-express miRNA-34a and IL-24 driven by an adenovirus endogenous E3 promoter in HCC cells. High levels of miRNA-34a and IL-24 expression were detected in AdCN205-IL-24-miR-34a-infected HCC cells. AdCN205-IL-24-miR-34a significantly induced dramatic antitumor activity, as compared with that induced by AdCN205-IL-24 or AdCN205-miR-34a alone. Transfer of miRNA-34a into HCC cells inhibited the expression of its target genes, Bcl-2 and SIRT1. Treatment of established xenograft HCC tumors with AdCN205-IL-24-miR-34a in a mouse model resulted in complete tumor regression without recurrence. Taken together, our data provide a promising and reasonable delivery strategy of double-aimed cancer therapy, in which miRNAs and tumor-suppressing genes are used simultaneously.
DNA methylation is an important epigenetic modification and is frequently altered in cancer. Convert of 5-methylcytosine (5 mC) to 5-hydroxymethylcytosine (5 hmC) by ten-eleven translocation (TET) family enzymes plays important biological functions in embryonic stem cells, development, aging and disease. Recent reports showed that level of 5 hmC was altered in various types of cancers. However, the change of 5 hmC level in hepatocellular carcinoma (HCC) and association with clinical outcome were not well defined. Here, we reported that level of 5 hmC was decreased in HCC tissues, as compared with non-tumor tissues. Clincopathological analysis showed the decreased level of 5 hmC in HCC was associated with tumor size, AFP level and poor overall survival. We also found that the decreased level of 5 hmC in non-tumor tissues was associated with tumor recurrence in the first year after surgical resection. In an animal model with carcinogen DEN-induced HCC, we found that the level of 5 hmC was gradually decreased in the livers during the period of induction. There was further reduction of 5 hmC in tumor tissues when tumors were developed. In contrast, level of 5 mC was increased in HCC tissues and the increased 5 mC level was associated with capsular invasion, vascular thrombosis, tumor recurrence and overall survival. Furthermore, our data showed that expression of TET1, but not TET2 and TET3, was downregulated in HCC. Taken together, our data indicated 5 hmC may be served as a prognostic marker for HCC and the decreased expression of TET1 is likely one of the mechanisms underlying 5 hmC loss in HCC.
Hepatocellular carcinoma (HCC) is a hypervascular cancer characterized by rapid progression as well as resistance to conventional chemotherapy. It has been shown that microRNAs play critical roles in pathogenesis of HCC. MicroRNA-122 (miR-122) is a liver-specific microRNA and is frequently downregulated in HCC. In the present study, we investigated whether restoration of miR-122 in HCC cells could render cells sensitive to chemotherapeutic agents adriamycin (ADM) or vincristine (VCR). Our data showed that overexpression of miR-122 in HCC cells induced by adenovirus expressing miR-122 could render cell sensitive to ADM or VCR. Analysis of cell cycle distribution showed that the anti-proliferative effect of miR-122 is associated with increase of cell number in the G2/M phase. Moreover, treatment with Ad-miR122 and ADM or VCR resulted in high accumulation of HCC cells in G2/M phase. We further demonstrated that overexpression of miR-122 could modulate the sensitivity of the HCC cells to chemotherapeutic drugs through downregulating MDR related genes MDR-1, GST-?, and MRP, antiapoptotic gene Bcl-w and cell cycle related gene cyclin B1. Taken together, our findings demonstrated that combination of Ad-miR122 with chemotherapeutic agents inhibited HCC cell growth by inducing G2/M arrest and that this arrest is associated, at least in part, with reduced expression of MDR related genes and Cyclin B1.
Recent studies have indicated that short hairpin RNA (shRNA) driven by RNA polymerase (Pol) II promoters can be transcribed into precursor mRNAs together with transgenes. It remains unclear, however, whether coexpression of shRNA and transgene from a single promoter is feasible for cancer therapy.
microRNA-122 (miR-122) plays an important role in both of hepatic physiology and pathology. Downregulation of miR-122 was reported in human primary hepatocellular carcinoma (HCC) and restoration of miR-122 could suppress the growth of cancer cells. In this study, we presented a novel strategy for cancer therapy based on gene transfer of miR-122 by adenoviral vector.
Both adoptive immunotherapy and gene therapy hold a great promise for treatment of malignancies. However, these strategies exhibit limited anti-tumor activity, when they are used alone. In this study, we explore whether combination of cytokine-induced killer (CIK) adoptive immunotherapy with oncolytic adenovirus-mediated transfer of human interleukin-12 (hIL-12) gene induce the enhanced antitumor potency. Our results showed that oncolytic adenovirus carrying hIL-12 (AdCN205-IL12) could produce high levels of hIL-12 in liver cancer cells, as compared with replication-defective adenovirus expressing hIL-12 (Ad-IL12). AdCN205-IL12 could specifically induce cytotoxocity to liver cancer cells. Combination of CIK cells with AdCN205-IL12 could induce higher antitumor activity to liver cancer cells in vitro than that induced by either CIK or AdCN205-IL12 alone, or combination of CIK and control vector AdCN205-GFP. Furthermore, treatment of the established liver tumors with the combined therapy of CIK cells and AdCN205-IL12 resulted in tumor regression and long-term survival. High level expression of hIL-12 in tumor tissues could increase traffic of CIK cells to tumor tissues and enhance their antitumor activities. Our study provides a novel strategy for the therapy of cancer by the combination of CIK adoptive immunotherapy with oncolytic adenovirus-mediated transfer of immune stimulatory molecule hIL-12.
The influence of solute-solute interactions on hormone retention during nanofiltration (NF) was quantified and mechanisms underlying retention identified. A new approach to predict both the mass of hormone sorbed to organic matter and the retention of hormone influenced by solute-solute interactions was applied. Laboratory-scale experiments were carried out in a cross-flow filtration system examining organic matter concentration, solution pH, and hormone type. Solute-solute interactions between HA and estrone improved estrone retention while decreasing estrone adsorption to membranes. HA concentration determined the amount of estrone bound to HA and hence affected estrone retention based on the mechanism of size exclusion. The solution pH influenced both solute-solute as well as solute-membrane interactions. Solute-solute interactions were most important below the pK(a) of estrone, whereas charge repulsion between estrone and negative functional groups of the membrane dominated estrone retention above the pK(a). Of the four hormones studied, progesterone had the greatest affinity for both HA and NF membrane, which was attributed to hydrogen bonding ability. Using partition coefficients K(OM) from solid-phase microextraction (SPME) resulted in very good agreement between predicted and experimental retention.
Hepatocellular carcinoma (HCC) exhibits cellular heterogeneity and embryonic stem-cell-related genes are preferentially overexpressed in a fraction of cancer cells of poorly differentiated tumors. However, it is not known whether or how these cancer cells contribute to tumor initiation and progression. Here, our data showed that increased expression of pluripotency transcription factor Nanog in cancer cells correlates with a worse clinical outcome in HCC. Using the Nanog promoter as a reporter system, we could successfully isolate a small subpopulation of Nanog-positive cells. We demonstrate that Nanog-positive cells exhibited enhanced ability of self-renewal, clonogenicity, and initiation of tumors, which are consistent with crucial hallmarks in the definition of cancer stem cells (CSCs). Nanog(Pos) CSCs could differentiate into mature cancer cells in in vitro and in vivo conditions. In addition, we found that Nanog(Pos) CSCs exhibited resistance to therapeutic agents (e.g., sorafenib and cisplatin) and have a high capacity for tumor invasion and metastasis. Knock-down expression of Nanog in Nanog(Pos) CSCs could decrease self-renewal accompanied with decreased expression of stem-cell-related genes and increased expression of mature hepatocyte-related genes. Overexpression of Nanog in Nanog(Neg) cells could restore self-renewal. Furthermore, we found that insulin-like growth factor (IGF)2 and IGF receptor (IGF1R) were up-regulated in Nanog(Pos) CSCs. Knock-down expression of Nanog in Nanog(Pos) CSCs inhibited the expression of IGF1R, and overexpression of Nanog in Nanog(Neg) cells increased the expression of IGF1R. A specific inhibitor of IGF1R signaling could significantly inhibit self-renewal and Nanog expression, indicating that IGF1R signaling participated in Nanog-mediated self-renewal.
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