The critical role of dysregulated Hh-FOXM1-TPX2 signaling in human hepatocellular carcinoma cell proliferation

Reappraisal of the Roles of the Sonic Hedgehog Signaling Pathway in Hepatocellular Carcinoma

HCC remains one of the leading causes of cancer-related death globally. The main challenges in treatments of hepatocellular carcinoma (HCC) primarily arise from high rates of postoperative recurrence and the limited efficacy in treating advanced-stage patients. Various signaling pathways involved in HCC have been reported. Among them, the Sonic hedgehog (SHH) signaling pathway is crucial. The presence of SHH ligands is identified in approximately 60% of HCC tumor tissues, including tumor nests. PTCH-1 and GLI-1 are detected in more than half of HCC tissues, while GLI-2 is found in over 84% of HCC tissues. The SHH signaling pathway (including canonical and non-canonical) is involved in different aspects of HCC, including hepatocarcinogenesis, tumor growth, tumor invasiveness, progression, and migration. The SHH signaling pathway also contributes to recurrence, metastasis, modulation of the cancer microenvironment, and sustaining cancer stem cells. It also affects the resistance of HCC cells to chemotherapy, target therapy, and radiotherapy. Reappraisal of the roles of the SHH signaling pathway in HCC may trigger some novel therapies for HCC.

GANT61, an inhibitor of Gli1, inhibits the proliferation and migration of hepatocellular carcinoma cells

Constitutive activation of Hedgehog (Hh) signaling has been implicated in many cancers including hepatocellular carcinoma (HCC). Among them, the terminal glioma-associated oncogene homolog 1 (Gli1) regulates the expression of critical genes in the Hh pathway. The current study aims to evaluate the anti-HCC effect of the Gli1 inhibitor, GANT61. In vitro analysis including cell counting kit-8 (CCK-8) assay, flow cytometry, and migration and invasion assay were adopted to evaluate the effect of GANT61 on HCC cell lines. In vivo, xenograft studies were also performed to verify the effect of GANT61 on HCC. By CCK-8 assay, we found that GANT61 could significantly reduce the growth of HCC cell lines Huh7 and hemophagocytic lymphohistiocytosis (HLE), and their IC50 concentrations were 4.481 and 6.734 μM, respectively. Flow cytometry shows that GANT61 induced cell cycle arrest in the G2/M phase and accelerated apoptosis of both HLE and Huh7 cells. While migration and invasion assay shows that GANT61 weakens cells' migration and invasion ability. Besides that, GANT61 inhibits the expression of Gli1, FoxM1, CyclinD1, and Bcl-2, upregulates the level of Bax protein, and also reverses the epithelial-mesenchymal transition program by downregulating the expression of Vimentin and N-Cadherin and upregulating the expression of epithelial E-Cadherin expression. Furthermore, GANT61 inhibits the growth of subcutaneous xenografts of Huh7 cells in nude mice. Overall, this study suggests that Gli1 is a potential target for therapy and GANT61 shows promising therapeutic potential for future treatment in HCC.

Ubenimex suppresses glycolysis mediated by CD13/Hedgehog signaling to enhance the effect of cisplatin in liver cancer

Background

Liver cancer ranks third in fatalities among all cancer-related deaths. As a traditional chemotherapy drug, the application of cis-Diamminedichloroplatinum (II) (cisplatin, CDDP) for the treatment of liver cancer is greatly limited by its side effects and high drug resistance. Therefore, we are in urgent need of a more effective and less toxic CDDP therapeutic regimen. Our research aimed to clarify the possible mechanism of ubenimex in enhancing the effect of CDDP on liver cancer.

Methods

The underlying mechanism was determined using Cell Counting Kit-8 (CCK-8) assay, flow cytometry, immunofluorescence, enzyme-linked immunosorbent assay (ELISA), transwell assay, wound healing assay and western blot assay.

Results

The data indicated that ubenimex suppressed the expression levels of glycolysis-related proteins by decreasing the expression levels of cluster of differentiation 13 (CD13), while overexpression of CD13 could restore the activity of glycolysis. The glycolysis inhibitor 2-deoxy-D-glucose enhanced the antiproliferative effect of ubenimex and CDDP. In addition, the inhibition of the activity levels of the Hedgehog (Hh) pathway members was accompanied by a decrease in CD13 expression, which was reversed following CD13 overexpression. Moreover, ubenimex inhibited the production of lactic acid and adenosine triphosphate (ATP), as well as the expression of key proteins involved in glycolysis, which was similar to the effects caused by the Hh inhibitor cyclopamine. However, the effects of ubenimex were mediated by targeting CD13, while cyclopamine exhibited no effects on CD13, suggesting that Hh signaling occurred in the downstream of CD13. The inhibition of glycolysis by cyclopamine was reduced following CD13 overexpression, which further indicated that ubenimex targeted the CD13/Hh pathway to inhibit glycolysis. Finally, wound healing and transwell assays and cell proliferation and apoptosis analysis demonstrated that ubenimex inhibited glycolysis by alleviating the CD13/Hh pathway, which in turn enhanced the effects of CDDP on inhibiting the progression of liver cancer.

Conclusions

Ubenimex inhibits glycolysis by targeting the CD13/Hh pathway, thus playing an anti-tumor role together with CDDP. This study demonstrated the adjuvant effect of ubenimex from the perspective of Hh signal-dependent glycolysis regulation.

TPX2 Amplification-Driven Aberrant Mitosis in Culture Adapted Human Embryonic Stem Cells with gain of 20q11.21

BACKGROUND

Despite highly effective machinery for the maintenance of genome integrity in human embryonic stem cells (hESCs), the frequency of genetic aberrations during in-vitro culture has been a serious issue for future clinical applications.

METHOD

By passaging hESCs over a broad range of timepoints (up to 6 years), the isogenic hESC lines with different passage numbers with distinct cellular characteristics, were established.

RESULT

We found that mitotic aberrations, such as the delay of mitosis, multipolar centrosomes, and chromosome mis-segregation, were increased in parallel with polyploidy compared to early-passaged hESCs (EP-hESCs) with normal copy number. Through high-resolution genome-wide approaches and transcriptome analysis, we found that culture adapted-hESCs with a minimal amplicon in chromosome 20q11.21 highly expressed TPX2, a key protein for governing spindle assembly and cancer malignancy. Consistent with these findings, the inducible expression of TPX2 in EP-hESCs reproduced aberrant mitotic events, such as the delay of mitotic progression, spindle stabilization, misaligned chromosomes, and polyploidy.

CONCLUSION

These studies suggest that the increased transcription of TPX2 in culture adapted hESCs could contribute to an increase in aberrant mitosis due to altered spindle dynamics.

Activation of the hedgehog signaling pathway is associated with the promotion of cell proliferation and epithelial-mesenchymal transition in chronic rhinosinusitis with nasal polyps

PURPOSE

To investigate the pathogenesis of the hedgehog (Hh) signaling pathway activated by inflammation in the development of chronic rhinosinusitis with nasal polyps (CRSwNP).

METHODS

The 82 people including CRSwNP patients (case group) and nasal septal deviation patients (control group) were recruited. The samples in the case group were collected and classified into two groups: mucosal tissue of nasal polyps (NP group) and mucosal tissue adjacent to nasal polyps (NM group), the samples were collected from the control group as CM group. Clinical characteristics were assessed. Hematoxylin and eosin (H&E) and immunohistochemical (IHC) staining were performed to detect eosinophils (EOS), the expression of the key genes of the pathway and epithelial-mesenchymal transition (EMT) markers in the samples.

RESULTS

There were significant differences in the nasal obstruction visual analog scale (VAS) score, rhinorrhea VAS score, percentage of blood EOS, blood EOS absolute counts and tissue EOS counts in the case group compared with the control group (P < 0.05). The EOS level and expression levels of PTCH1, SMO, Gli1, Gli2, Ki67 and vimentin were higher in NP group than in the other two groups (P < 0.05). E-cadherin expression was decreased in NP group (P < 0.05). A positive correlation between PTCH1 expression and CRSwNP Lund-Mackay score in NP group.

CONCLUSIONS

Our results indicated that the activation of Hh signaling pathway might promote cell proliferation and EMT occurrence, ultimately leading to the development of CRSwNP, which might provide a new target for treatment.

TPX2 promotes ovarian tumorigenesis by interacting with Lamin A/C and affecting its stability

OBJECTIVE

Ovarian cancer (OC) is one of the fatal gynecologic malignancies. However, there are no effective prognostic or therapeutic indicators for OC. Herein, we aim to reveal the potential function of targeting protein for Xklp2 (TPX2) in OC progression.

METHODS

Immunohistochemical and bioinformatic analyses were used to evaluate the level of TPX2 in OC samples. Effects of TPX2 on cell proliferation, cell apoptosis and ROS production were evaluated in vivo and in vitro. Mass spectrometry, Co-IP and immunofluorescence assays were performed to identify and verify protein-protein interactions.

RESULTS

Our data showed that pathological overexpression (OE) of the TPX2 in OC could manifest a poor prognosis. Functional studies demonstrated that TPX2 silencing led to the suppression of cell proliferation in vitro and in vivo through an increase in reactive oxygen species (ROS) level and apoptosis, while TPX2 OE exhibited the opposite effect. Furthermore, by mass spectrometric analysis, we identified a novel interacting partner, Lamin A/C, for TPX2. Mechanistically, TPX2 regulated Lamin A/C's stability by modulating the level of phospho-Lamin A/C (Ser 22).

CONCLUSION

Our findings thus suggest that TPX2 may be a promising therapeutic target for OC.

TPX2 prompts mitotic survival via the induction of BCL2L1 through YAP1 protein stabilization in human embryonic stem cells

Genetic alterations have been reported for decades in most human embryonic stem cells (hESCs). Survival advantage, a typical trait acquired during long-term in vitro culture, results from the induction of BCL2L1 upon frequent copy number variation (CNV) at locus 20q11.21 and is one of the strongest candidates associated with genetic alterations that occur via escape from mitotic stress. However, the underlying mechanisms for BCL2L1 induction remain unknown. Furthermore, abnormal mitosis and the survival advantage that frequently occur in late passage are associated with the expression of BCL2L1, which is in locus 20q11.21. In this study, we demonstrated that the expression of TPX2, a gene located in 20q11.21, led to BCL2L1 induction and consequent survival traits under mitotic stress in isogenic pairs of hESCs and human induced pluripotent stem cells (iPSCs) with normal and 20q11.21 CNVs. High Aurora A kinase activity by TPX2 stabilized the YAP1 protein to induce YAP1-dependent BCL2L1 expression. A chemical inhibitor of Aurora A kinase and knockdown of YAP/TAZ significantly abrogated the high tolerance to mitotic stress through BCL2L1 suppression. These results suggest that the collective expression of TPX2 and BCL2L1 from CNV at loci 20q11.21 and a consequent increase in YAP1 signaling promote genome instability during long-term in vitro hESC culture.

Construction and validation of prognostic signature for hepatocellular carcinoma basing on hepatitis B virus related specific genes

BACKGROUND

Hepatocellular carcinoma (HCC) is a frequent primary liver cancer, and it is one of the leading cause of cancer-related deaths. Hepatitis B virus (HBV) infection is a crucial risk factor for HCC. Thus, this study aimed to explore the prognostic role of HBV-positive HCC related specific genes in HCC.

METHODS

The HCC related data were downloaded from three databases, including The Cancer Genome Atlas (TCGA), International Cancer Genome Consortium (ICGC), and Gene Expression Omnibus (GEO). Univariate Cox regression analysis and LASSO Cox regression analysis were conducted to build the Risk score. Multivariate Cox regression analysis and survival analysis determined the independent prognostic indicators.

RESULTS

After cross analysis of differentially expressed genes (DEGs), we have identified 106 overlapped DEGs, which were probably HBV-positive HCC related specific genes. These 106 DEGs were significantly enriched in 213 GO terms and 8 KEGG pathways. Among that, 11 optimal genes were selected to build a Risk score, and Risk score was an independent prognostic factor for HCC. High risk HCC patients had worse OS. Moreover, five kinds of immune cells were differentially infiltrated between high and low risk HCC patients.

CONCLUSION

The prognostic signature, based on HMMR, MCM6, TPX2, KIF20A, CCL20, RGS2, NUSAP1, FABP5, FZD6, PBK, and STK39, is conducive to distinguish different prognosis of HCC patients.

Comprehensive Analysis of the Oncogenic Role of Targeting Protein for Xklp2 (TPX2) in Human Malignancies

Mitosis and spindle assembly require the microtubule-associated protein Xenopus kinesin-like protein 2 (TPX2). Although TPX2 is highly expressed in several malignant tumor forms, little is known about its role in cancer. In this study, we performed the gene set enrichment analysis of TPX2 in 33 types of cancers and an extensive pan-cancer bioinformatic analysis using prognosis, tumor mutational burdens, microsatellite instability, tumor microenvironment, and immune cell infiltration data. According to the differential expression study, TPX2 was found to be overexpressed across all studied cancer types. Based on the survival analysis, increased TPX2 expression was associated with a poor prognosis for most cancers. The TPX2 expression level was confirmed to correlate with the clinical stage, microsatellite instability, and tumor mutational burden across all cancer types. Furthermore, TPX2 expression has been linked to tumor microenvironments and immune cell infiltration, particularly in bladder urothelial carcinoma, liver hepatocellular carcinoma, lung adenocarcinoma, stomach adenocarcinoma, and uterine corpus endometrial carcinoma. Finally, the gene set enrichment analysis implicated TPX2 in the regulation of aminoacyl tRNA biosynthesis, which is the most important tumor cell cycle signaling pathway. This comprehensive pan-cancer analysis shows that TPX2 is a prognostic molecular biomarker for most cancers and suggests its potential as an effective therapeutic target for the treatment of these diseases.

FOXM1 Is a Novel Molecular Target of AFP-Positive Hepatocellular Carcinoma Abrogated by Proteasome Inhibition

Alpha-fetoprotein (AFP) is an oncofetal protein that is elevated in a subset of hepatocellular carcinoma (HCC) with poor prognosis, but the molecular target activated in AFP-positive HCC remains elusive. Here, we demonstrated that the transcription factor forkhead box M1 (FOXM1) is upregulated in AFP-positive HCC. We found that FOXM1 expression was highly elevated in approximately 40% of HCC cases, and FOXM1-high HCC was associated with high serum AFP levels, a high frequency of microscopic portal vein invasion, and poor prognosis. A transcriptome and pathway analysis revealed the activation of the mitotic cell cycle and the inactivation of mature hepatocyte metabolism function in FOXM1-high HCC. The knockdown of FOXM1 reduced AFP expression and induced G2/M cell cycle arrest. We further identified that the proteasome inhibitor carfilzomib attenuated FOXM1 protein expression and suppressed cell proliferation in AFP-positive HCC cells. Carfilzomib in combination with vascular endothelial growth factor receptor 2 (VEGFR2) blockade significantly prolonged survival by suppressing AFP-positive HCC growth in a subcutaneous tumor xenotransplantation model. These data indicated that FOXM1 plays a pivotal role in the proliferation of AFP-positive liver cancer cells. Carfilzomib can effectively inhibit FOXM1 expression to inhibit tumor growth and could be a novel therapeutic option in patients with AFP-positive HCC who receive anti-VEGFR2 antibodies.

FOXM1-induced TYMS upregulation promotes the progression of hepatocellular carcinoma

Background

Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer and one of the major causes of cancer-related death. Thymidylate synthase (TYMS) catalyzes the methylation of deoxy guanosine to deoxy thymidylate, which is a crucial gene for DNA repair and replication. Thus, TYMS was reported to be closely associated with developing a variety of tumors, but it has been poorly studied in HCC.

Materials and methods

We used the cell counting kit-8 (CCK-8), BrdU, and CFSE assay to measure cell proliferation. The flow cytometry assay and the TUNEL assay were used for assessing cell apoptosis. The flow cytometry assay was used to analyze the cell cycle. The Transwell invasion assay and the wound healing assay were conducted to determine the invasive ability of the cells. RT-qPCR and Western blot analyses were performed to evaluate the mRNA and protein expression levels of specific genes, respectively.

Results

TYMS was found to be upregulated in both HCC cells and patient samples. High expression of TYMS was associated with an unfavorable prognosis in HCC patients based on the TCGA-LIHC dataset. Cell proliferation, apoptosis, and invasion assays revealed that TYMS promoted the proliferation and invasion of HCC cells as well as inhibited apoptosis. In addition, TYMS is a downstream target of FOXM1. TYMS knockdown reversed the 5-FU resistance caused by FOXM1 overexpression and re-sensitized HCC cells to 5-FU treatment.

Conclusion

This study suggested that TYMS serves as an oncogene in HCC, and targeting the FOXM1-TYMS axis may help improve the survival of HCC patients as well as provide new insights for treating advanced HCC patients.

Hedgehog-Gli2 Signaling Promotes Chemoresistance in Ovarian Cancer Cells by Regulating MDR1

Background

Cisplatin (DDP) resistance remains a key challenge in improving the clinical outcome of patients with ovarian cancer (OC). Gli2 overexpression can lead to DDP resistance in OC cells, but the specific underlying regulatory mechanism remains unclear. The membrane transporter encoding gene MDR1 positively regulates chemotherapy resistance in various cancer types. We evaluated MDR1 as a potential Gli2 downstream target and the contribution of the Gli2/MDR1 axis in promoting DDP resistance in OC cells.

Methods

To generate drug-resistant SKOV3/DDP cells, SKOV3 cells were grown for six months under continuous induction wherein the DDP concentration was steadily increased. Gli2 expression in OC cells with varying DDP sensitivities was detected using western blot. Cell counting kit-8 assays were used to assess the DDP sensitivity of SKOV3, SKOV3/DDP, A2780, and A2780/DDP cells and reversal of DDP resistance in SKOV3/DDP and A2780/DDP cells. Cell proliferation was analyzed using 5-ethynyl-2′-deoxyuridine (EdU) incorporation assays. The transcriptional regulation of MDR1 by Gli2 was determined using luciferase reporter assays. Finally, xenograft OC tumors were generated in nude mice, which were then treated with intraperitoneal DDP or phosphate-buffered saline (PBS) injections to investigate if Gli2 affected DDP resistance in OC in vivo.

Results

DDP-resistant SKOV3/DDP and A2780/DDP cells showed higher expression of Gli2 and MDR1 as compared with that in DDP-sensitive OC cells. Gli2 knockdown in SKOV3/DDP cells significantly reduced MDR1 expression, whereas it increased DNA damage, thereby sensitizing OC cells to DDP. Similar results were obtained after targeting Gli2 expression with the Gli-antagonist 61 inhibitor (GANT61) in SKOV3/DDP and A2780/DDP cells. In cells stably overexpressing Gli2, treatment with gradient concentrations of verapamil, an MDR1 inhibitor, significantly inhibited MDR1 expression. Our findings indicate that downregulation of MDR1 expression may reverse OC cell resistance to DDP. Moreover, dual-luciferase reporter gene assays confirmed that MDR1 is a direct downstream target of Gli2, with Gli2 positively regulating MDR1 expression. Finally, subcutaneous xenotransplantation in nude mice demonstrated that Gli2 plays a key role in regulating OC drug resistance.

Conclusions

We identified a mechanism by which Hedgehog-Gli signaling regulates OC chemoresistance by modulating MDR1 expression. Hence, Gli2 and MDR1 are potential biomarkers and therapeutic targets in patients with chemoresistant OC.

Aberrant expression of the extracellular matrix component Biglycan regulated by Hedgehog signalling promotes colorectal cancer cell proliferation

Hedgehog (Hh) signalling plays essential roles in regulating embryonic development and contributes to tumour initiation, growth and progression in multiple cancers. The detailed mechanism by which Hh signalling participates in tumour growth warrants thorough study, although several downstream target genes have been identified. Herein, a set of novel targets of Hh signalling was identified in multiple types of tumour cells via RNA-Seq analysis. Among these targets, the expression regulation and oncogenic function of the extracellular matrix component biglycan (BGN) were investigated. Further investigation verified that Hh signalling activates the expression of BGN via the transcription factor Gli2, which directly binds to the promoter region of BGN. Functional assays revealed that BGN facilitates tumour cell growth and proliferation in colorectal cancer (CRC) cells, and xenograft assays confirmed that BGN also promotes tumour growth . Moreover, analysis of clinical CRC samples showed that both the protein and mRNA levels of BGN are increased in CRC tissues compared to those in adjacent tissues, and higher expression of BGN is correlated with poorer prognosis of CRC patients, further confirming the function of BGN in CRC. Taken together, aberrantly activated Hh signalling increases the expression of BGN, possibly regulates the extracellular matrix, and thereby promotes tumour growth in CRC.

Identification of biomarkers related to glycolysis with weighted gene co-expression network analysis in oral squamous cell carcinoma

BACKGROUND

Oral squamous cell carcinoma (OSCC) is the most common tumor in the oral cavity and maxillofacial region. Increasing evidence suggests that aerobic glycolysis plays an important role in the occurrence, development, and prognosis of OSCC. Therefore, the identification of biomarkers related to glycolysis in OSCC represents considerable potential for improving its treatment.

METHODS

In the present study, a single-sample gene-set enrichment analysis (ssGSEA) algorithm with weighted gene co-expression network analysis (WGCNA) were used to quantify the degree of glycolysis and identify key modules with the greatest correlation with glycolysis.

RESULTS

Glycolytic scores significantly correlated with prognosis. In the key module 5 HUB genes were finally selected, which displayed a robust predictive effect. The expressions of key genes were associated with glycolysis.

CONCLUSIONS

The research comprehensively analyzed the glycolysis of OSCC and identified several biomarkers related to glycolysis. These biomarkers may represent potential therapeutic targets for future OSCC therapy.

DNAJC5 promotes hepatocellular carcinoma cells proliferation though regulating SKP2 mediated p27 degradation

DNAJC5 (DnaJ heat shock protein family (Hsp40) member C5), also known as cysteine tandem protein (CSPα), is important for maintaining the normal function of nerve tissues, but its oncogenic function remains unknown. Here, we report a unique mechanism underlying the oncogenic function of DNAJC5. DNAJC5 protein expression is highly detectable in human hepatocellular carcinoma (HCC) tissues and is strongly related to a poor prognosis among HCC patients. DNAJC5 overexpression promotes HCC cell proliferation and reduced the ratio of cells in G₁ phase of the cell cycle. Furthermore, DNAJC5 interacts with SKP2 and enhances the degradation of p27 (a cyclin-dependent kinase inhibitor1B) by promoting formation of the SKP2-p27 complex. In contrast, DNAJC5 knockdown rescues the SKP2-mediated decrease in p27 protein levels. These results reveal that the DNAJC5-SKP2-p27 pathway is a novel mechanism for the oncogenic function of DNAJC5 in HCC.