Harmine reinforces the effects of regorafenib on suppressing cell proliferation and inducing apoptosis in liver cancer cells

ABSTRACT The abnormal proliferation of cancer cells is driven by deregulated oncogenes or tumor suppressors, among which the cancer-vulnerable genes are attractive therapeutic targets. Targeting mislocalization of oncogenes and tumor suppressors resulting from aberrant nuclear export is effective for inhibiting growth transformation of cancer cells. We performed a clustered regularly interspaced short palindromic repeat (CRISPR)-associated (Cas) screening in a unique model of matched primary and oncogenic Kaposi’s sarcoma-associated herpesvirus (KSHV)-transformed cells and identified genes that were growth promoting and growth suppressive for both types of cells, among which exportin XPO1 was demonstrated to be critical for the survival of transformed cells. Using XPO1 inhibitor KPT-8602 and by small interfering RNA (siRNA) knockdown, we confirmed the essential role of XPO1 in cell proliferation and growth transformation of KSHV-transformed cells and in cell lines of other cancers, including gastric cancer and liver cancer. XPO1 inhibition induced cell cycle arrest through p53 activation, but the mechanisms of p53 activation differed among the different types of cancer cells. p53 activation depended on the formation of promyelocytic leukemia (PML) nuclear bodies in gastric cancer and liver cancer cells. Mechanistically, XPO1 inhibition induced relocalization of autophagy adaptor protein p62 (SQSTM1), recruiting p53 for activation in PML nuclear bodies. Taken the data together, we have identified novel growth-promoting and growth-suppressive genes of primary and cancer cells and have demonstrated that XPO1 is a vulnerable target of cancer cells. XPO1 inhibition induces cell arrest through a novel PML- and p62-dependent mechanism of p53 activation in some types of cancer cells. IMPORTANCE Using a model of oncogenic virus KSHV-driven cellular transformation of primary cells, we have performed a genome-wide CRISPR-Cas9 screening to identify vulnerable genes of cancer cells. This screening is unique in that this virus-induced oncogenesis model does not depend on any cellular genetic alterations and has matched primary and KSHV-transformed cells, which are not available for similar screenings in other types of cancer. We have identified genes that are both growth promoting and growth suppressive in primary and transformed cells, some of which could represent novel proto-oncogenes and tumor suppressors. In particular, we have demonstrated that the exportin XPO1 is a critical factor for the survival of transformed cells. Using a XPO1 inhibitor (KPT-8602) and siRNA-mediated knockdown, we have confirmed the essential role of XPO1 in cell proliferation and in growth transformation of KSHV-transformed cells, as well as of gastric and liver cancer cells. XPO1 inhibition induces cell cycle arrest by activating p53, but the mechanisms of p53 activation differed among different types of cancer cells. p53 activation is dependent on the formation of PML nuclear bodies in gastric and liver cancer cells. Mechanistically, XPO1 inhibition induces relocalization of autophagy adaptor protein p62 (SQSTM1), recruiting p53 for activation in PML nuclear bodies. These results illustrate that XPO1 is a vulnerable target of cancer cells and reveal a novel mechanism for blocking cancer cell proliferation by XPO1 inhibition as well as a novel PML- and p62-mediated mechanism of p53 activation in some types of cancer cells.

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Liver Cancer Cells Uptake Labile Iron via L-type Calcium Channel to Facilitate the Cancer Cell Proliferation

Cell Biochemistry and Biophysics ◽

10.1007/s12013-020-00951-0 ◽

2020 ◽

Author(s):

Isara Phiwchai ◽

Titipun Thongtem ◽

Somchai Thongtem ◽

Chalermchai Pilapong

Keyword(s):

Cell Proliferation ◽

Liver Cancer ◽

Calcium Channel ◽

Cancer Cells ◽

Cancer Cell ◽

Cancer Cell Proliferation ◽

Liver Cancer Cells ◽

Labile Iron

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TUG1 Promotes the Expression of IFITM3 in Hepatocellular Carcinoma by Competitively Binding to miR-29a

10.21203/rs.3.rs-70822/v1 ◽

2020 ◽

Author(s):

Qian Feng ◽

Weiwei Liu ◽

Wenjun Liao ◽

Jun Gao ◽

Jiyuan Ai ◽

...

Keyword(s):

Hepatocellular Carcinoma ◽

Cell Proliferation ◽

Liver Cancer ◽

Cancer Cells ◽

Cell Invasion ◽

Human Liver ◽

Target Gene ◽

Liver Cancer Cells ◽

Tumor Tissues ◽

Hcc Cells

Abstract Background: Numerous studies have demonstrated the important relationship of TUG1 with tumorigenesis. The present study investigated the role of TUG1 and its downstream genes miR-29a and IFITM3 in the occurrence and development of hepatocellular carcinoma (HCC). We found that both TUG1 and IFITM3 genes are highly expressed in HCC, whereas the expression of miR-29a is low in HCC. Downregulation of TUG1 reduces cell invasion, metastasis, and cell proliferation ability and promotes cell apoptosis. Simultaneous downregulation of miR-29a reverses this effect. Moreover, IFITM3, as the target gene of miR-29a, is positively regulated by TUG1. However, the adjustment relationship between these three components is still unknown and thus warrants further investigation. The present study investigated the regulatory relationship between TUG1, miR-29a, and IFITM3 in human liver cancer.Methods: The expression of TUG1 and miR-29a in tumor tissues and adjacent non-tumor tissues of 65 patients with HCC was detected by real-time quantitative polymerase chain reaction (RT-qPCR). The migration and invasion of liver cancer cells were studied by the wound healing assay and the Transwell method, respectively. The apoptosis rate of HCC cells was detected by flow cytometry, and the proliferation rate of hepatoma cells was detected by the 5-ethynyl-2′-deoxyuridine (EDU) method. Immunofluorescence was used to detect the expression of TUG1 and IFITM3 in HCC-LM3 and HL-7702 cell lines. The relationship between TUG1 and miR-29a was detected using a double luciferase reporter assay and fluorescence in situ hybridization (FISH). Tumors were established in vivo by subcutaneous injection of HCC cells into nude mice and injection of these cells into the tail vein. Western blotting was used to quantify the biomarkers.Results: The expression of TUG1 increased significantly in tumor tissues and HCC cells. Moreover, the expression of miR-29a in liver cancer tissues was significantly lower than that in normal human liver tissues. The expression of TUG1 in liver cancer tissue was negatively correlated with miR-29a. Knockdown of TUG1 weakened the invasion, migration, and proliferation of HCC cells, and enhanced their apoptosis. A simultaneous knockdown of miR-29a enhanced cell invasion, metastasis, and cell proliferation, whereas the apoptosis ability decreased. As a target gene of miR-29a, IFITM3 is not only negatively regulated by miR-29a, but also positively regulated by TUG1. Therefore, TUG1 regulates IFITM3 in HCC cells by competitively binding to miR-29a, thus affecting cell invasion, migration, proliferation, and apoptosis.Conclusion: As a CeRNA, TUG1 competitively binds to miR-29a to regulate IFITM3 and promote the development of liver cancer. Downregulation of TUG1 can significantly inhibit the migration, invasion, and proliferation of liver cancer cells. Based on these results, we conclude that TUG1 could serve as a key gene to improve the prognosis of patients with HCC.

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CRISPR-Cas9 screening of KSHV-transformed cells identifies XPO1 as a vulnerable target of cancer cells

10.1101/601369 ◽

2019 ◽

Author(s):

Marion Gruffaz ◽

Hongfeng Yuan ◽

Wen Meng ◽

Hui Liu ◽

Sangsu Bae ◽

...

Keyword(s):

Cell Proliferation ◽

Liver Cancer ◽

Cancer Cells ◽

Tumor Suppressors ◽

Nuclear Bodies ◽

Transformed Cells ◽

Liver Cancer Cells ◽

Pml Nuclear Bodies ◽

Growth Transformation ◽

P53 Activation

AbstractThe abnormal proliferation of cancer cells is driven by deregulated oncogenes or tumor suppressors, of which the cancer vulnerable genes are attractive therapeutic targets. Targeting mislocalization of oncogenes and tumor suppressors resulting from aberrant nuclear export is effective for inhibiting growth transformation of cancer cells. We performed a CRISPR-Cas9 screening in a unique model of matched primary and oncogenic KSHV-transformed cells, and identified genes that were pro-growth and growth-suppressive of both cells, of which exportin XPO1 was demonstrated to be critical for the survival of transformed cells. Using XPO1 inhibitor KPT-8602 and by siRNA knockdown, we confirmed the essential role of XPO1 in cell proliferation and growth transformation of KSHV-transformed cells, and cell lines of other cancers including gastric cancer and liver cancer. XPO1 inhibition induced cell cycle arrest through p53 activation but the mechanism of p53 activation differed among different types of cancer cells. p53 activation depended on the formation of PML nuclear bodies in gastric cancer and liver cancer cells. Mechanistically, XPO1 inhibition induced relocalization of autophagy adaptor protein p62 (SQSTM1), recruiting p53 for activation in PML nuclear bodies. Taken together, we have identified novel pro-growth and growth-suppressive genes of primary and cancer cells, and demonstrated XPO1 as a vulnerable target of cancer cells. XPO1 inhibition induces cell arrest through a novel PML-and p62-dependent mechanism of p53 activation in some types of cancer cells.ImportanceUsing a model of oncogenic virus KSHV driven cellular transformation of primary cells, we have performed a genome-wide CRISPR-Cas9 screening to identify vulnerable genes of cancer cells. This screening is unique in that this virus-induced oncogenesis model does not depend on any cellular genetic alterations, and has matched primary and KSHV-transformed cells, which are not available for similar screenings in other types of cancer. We have identified genes that are both pro-growth and growth-suppressive in primary and transformed cells, some of which could represent novel proto-oncogenes and tumor suppressors. In particular, we have demonstrated exportin XPO1 as a critical factor for the survival of transformed cells. Using a XPO1 inhibitor KPT-8602 and by siRNA-mediated knockdown, we have confirmed the essential role of XPO1 in cell proliferation and growth transformation of KSHV-transformed cells, as well as gastric and liver cancer cells. XPO1 inhibition induces cell cycle arrest by activating p53 but the mechanism of p53 activation differed among different types of cancer cells. p53 activation is dependent on the formation of PML nuclear bodies in gastric and liver cancer cells. Mechanistically, XPO1 inhibition induces relocalization of autophagy adaptor protein p62 (SQSTM1), recruiting p53 for activation in PML nuclear bodies. These results illustrate XPO1 as a vulnerable target of cancer cells, and reveal a novel mechanism for blocking cancer cell proliferation by XPO1 inhibition as well as a novel PML-and p62-mediated mechanism of p53 activation in some types of cancer cells.

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Tumor Cells Talk to Normal Cells Through Exosomes to Rebuild the Tumor Microenvironment

10.21203/rs.3.rs-444267/v1 ◽

2021 ◽

Author(s):

Chunwen Pu ◽

Qi Wang ◽

Aijun Sun ◽

Ping Sun ◽

Hui Huang ◽

...

Keyword(s):

Cell Cycle ◽

Flow Cytometry ◽

Cell Proliferation ◽

Tumor Microenvironment ◽

Liver Cancer ◽

Cancer Cells ◽

Cell Invasion ◽

Hepg2 Cells ◽

Normal Cells ◽

Liver Cancer Cells

Abstract BackgroundExosomes play a key role in the growth of normal cells and various diseases such as cancer. Tumor exosomes regulate the connection between normal cells and cancer cells in the tumor microenvironment, thereby promoting the growth and invasion of cancer cells.MethodsWe used HepG2 cells silenced by shRNA targeting GPC3, LO2 and HepG2 cells treated with different concentrations of GPC3. We determined the effects of GPC3 on cell proliferation, apoptosis and invasion using CCK8, flow cytometry and Transwell, and Western blotting Method to determine the expression of GPC3/WNT3A/β-catenin.HepG2 exosomes (Exo) and HepG2 exosomes treated with shRNA targeting GPC3 (sh-GPC3-Exo) were used to treat LO2 and HepG2 cells separately. Cell proliferation was measured by CCK8 experiment.The cell cycle and apoptosis were measured by flow cytometry. The cell invasion ability was analyzed by Transwell. The expression of GPC3/WNT3A/β-catenin signal protein was determined by Western blotting.ResultsThis is the first study to prove the bidirectional regulation of GPC3 between normal cells and liver cancer cells. After treatment of LO2 cells and HepG2 cells with GPC3, the LO2 cell cycle was blocked in the G0/G1 phase, while inhibiting cell proliferation, promoting cell apoptosis and invasion, but for HepG2 cells it appeared to promote proliferation.Silencing GPC3 can inhibit the proliferation and invasion, and promote cell apoptosis of HepG2. Subsequent experiments found that the expression of GPC3 was found in both LO2 and HepG2 exosomes, and the expression of GPC3 in HepG2 exosomes was significantly higher than that in LO2 exosomes. These suggest that GPC3 in exosomes has the potential to become a biomarker of HCC.In addition, HepG2 exosomes (Exo) can inhibit the proliferation of LO2 cells and promote apoptosis and invasion, which is consistent with the effect of GPC3 treatment. We also found that GPC3 is contained in HepG2 exosomes (shGPC3-Exo) that have silenced GPC3, which has the same effect on LO2 cells as HepG2 exosomes (Exo), but the degree of influence is reduced. shGPC3-Exo showed a promoting effect on the proliferation of HepG2 cells, but inhibited cell invasion. Therefore, GPC3 in Exo plays a role in the proliferation of LO2 cells and HepG2 cells. Further studies have shown that GPC3 in liver cancer exosomes regulates the proliferation, apoptosis and invasion of LO2 and HepG2 cells through the Wnt /β-catenin signaling pathway.ConclusionGPC3 in the exosomes of liver cancer cells inhibits the proliferation of normal liver cells and promotes apoptosis by activating the Wnt/β-catenin signaling pathway, promotes the proliferation of liver cancer cells, and assists the occurrence and development of HCC.

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