Imaging with 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) is used to determine sites of abnormal glucose metabolism to predict high tumor grade, metastasis, and poor patient survival. However, not all tumors with increased 18F-FDG uptake show aggressive tumor biology, as evident from the moderate correlation between metastasis and high FDG uptake. We hypothesized that metastasis is likely attributable to the complexity and heterogeneity of the cancer microenvironment. To identify the cancer microenvironment that induces the epithelial-mesenchymal transition (EMT) process, tumor areas of patients with HCC were analyzed by immunostaining. Our data demonstrated the induction of EMT process in HCC cells with low proliferation under hypoxic conditions. To validate our finding, among HCC cell lines, HepG2 cells with highly increased expression of HIF1α under hypoxia were employed in vitro and in vivo. Major changes in EMT-associated protein expression, such as the up-regulation of N-cadherin and snail/slug are associated with decreased proliferation-related protein (PCNA) caused by glucose deprivation under hypoxia. Indeed, PCNA knockdown-HepG2 cells under hypoxia showed the induction of more EMT process compare to the control. Thus, HCC cells with low proliferative potential under glucose-deprived and hypoxic conditions show high probability for induced EMT process and promote cell invasion. This study investigates reasons as to why an EMT process cannot fully be predicted. Our observations indicate that rather than analyzing a single factor, an integrated analysis of hypoxia with low glucose metabolism and low cell proliferation might be helpful to predict the potential impact on induction of EMT process and promotion of cell invasion.Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related deaths worldwide and is associated with various risk factors such as hepatitis virus infection, aflatoxin exposure, fatty liver, or alcohol abuse 1,2 . HCC is a clinical, metabolic, and heterogeneous tumor with various phenotypes 1-6 . Tumors include proliferating, slow dividing, quiescent or necrotic/apoptotic tumor cell populations, as well as fast-or slow-migrating tumor cells 7,8 . Genetic heterogeneity in solitary disseminated tumor cells and metastasis has been shown by genetic and expression profiling studies 9-15 . One of the known causes of heterogeneity related to rapid cellular proliferation is the formation of abnormal vascular networks characterized by leaking and compressed blood and lymphatic vessels, creating hypoxic areas in the tumors. Tumor hypoxia induces metabolic reprogramming from mitochondrial oxidation to glycolysis and drug resistance by activating pathways controlled by hypoxia-inducible factor (HIF) 16,17 . Moreover, there is a close relationship between hypoxia and tumor metastasis that leads to poor prognosis 18-20 .Epithelial-mesenchymal transition (EMT) is a complex trans-differentiation process that increases the migratory and invasive ...
In this work, the influence of parylene N film on the spheroid formation of osteoblast-like cells (MG-63) was determined and compared with that of high-hydrophilicity microenvironments, such as hydrophilic culture matrix and ultraviolet-treated parylene N film. To elucidate the change in cell properties due to the microenvironment of parylene N film, global gene expression profiles of MG-63 cells on parylene N film were analyzed. We confirmed the upregulated expression of osteoblast differentiation- and proliferation-related genes, such as Runx2, ALPL, and BGLAP and MKi67 and PCNA, respectively, using the real-time polymerase chain reaction. In addition, the differentiation and proliferation of osteoblast cells cultured on parylene N film were validated using immunostaining. Finally, the formation of spheroids and regulation of differentiation in human mesenchymal stem cells (MSCs) on parylene N film was demonstrated. The results of this study confirm that the microenvironment with the controlled hydrophobic property of parylene N film could effectively trigger the bone differentiation and maintains the proliferation of MSCs, similar to MG-63 cells without any scaffold structures or physical treatments.
Background: Hepatocellular carcinoma (HCC) is the leading cause of cancer-related deaths worldwide. The only drug currently approved for clinical use in the treatment of advanced HCC is sorafenib. However, many patients with HCC show reduced sensitivity to sorafenib during treatment. SIRT3, a member of the mammalian sirtuin family, is a tumor suppressor in certain tumor types. However, only few studies have investigated the effects of SIRT3 on tumor prognosis and sorafenib sensitivity in patients with HCC. Here, we aimed to investigate the correlation between SIRT3 expression and glucose metabolism and proliferation in HCC and discover effective compounds that increase endogenous SIRT3 modulation effect of sorafenib. Methods: To determine the correlation between SIRT3 and glucose related proteins, immunostaining was performed with liver cancer tissue using various antibodies. To investigate whether the expression of SIRT3 in HCC is related to the resistance to sorafenib, we treated sorafenib after the modulation of SIRT3 levels in HCC cell lines (overexpression in Huh7, knockdown in HepG2). We also employed PD0332991 to modulate the SIRT3 expression in HCC cell and conducted functional assays. Results: SIRT3 expression was downregulated in high glycolytic and proliferative HCC cells of human patients, xenograft model and HCC cell lines. Moreover, SIRT3 expression was downregulated after sorafenib treatment, resulting in reduced drug sensitivity in HCC cell lines. To enhance the anti-tumor effect of sorafenib, we employed PD0332991 (CDK4/6-Rb inhibitor) based on the correlation between SIRT3 and phosphorylated retinoblastoma protein in HCC. Notably, combined treatment with sorafenib and PD0332991 showed an enhancement of the antitumor effect in HCC cells. Conclusions: Our data suggest that the modulation of SIRT3 by CDK4/6 inhibition might be useful for HCC therapy together with sorafenib, which, unfortunately, has limited efficacy and whose use is often associated with drug resistance.
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