The receptor for activated protein kinase C promotes cell growth, invasion and migration in cervical cancer

Neuropilin-1 enhances temozolomide resistance in glioblastoma via the STAT1/p53/p21 axis

Glioblastoma (GBM) is the most prevalent primary intracranial tumor. Temozolomide (TMZ) is the first-line chemotherapy for GBM. Nonetheless, the development of TMZ resistance has become a main cause of treatment failure in GBM patients. Evidence suggests that neuropilin-1 (NRP-1) silencing can attenuate GBM cell resistance to TMZ. This study aims to determine potential mechanisms by which NRP-1 affects TMZ resistance in GBM. The parental U251 and LN229 GBM cells were exposed to increasing concentrations of TMZ to construct TMZ-resistant GBM cells (U251/TMZ, LN229/TMZ). BALB/c nude mice were injected with U251/TMZ cells to establish the xenograft mouse model. Functional experiments were carried out to examine NRP-1 functions. Western blotting and real-time quantitative polymerase chain reaction were used to evaluate molecular protein and mRNA expression, respectively. Immunohistochemical staining showed NRP-1 and STAT1 expression in mouse tumors. The results showed that NRP-1 was highly expressed in TMZ-resistant cells. Moreover, knocking down NRP-1 attenuated the TMZ resistance of U251/TMZ cells, while upregulating NRP-1 enhanced TMZ resistance of the parental cells. NRP-1 silencing elevated GBM cell sensitivity to TMZ in tumor-bearing mice. Depleting NRP-1 reduced STAT1, p53, and p21 expression in U251/TMZ cells. STAT1 depletion offset NRP-1 silencing evoked attenuation of GBM cell resistance to TMZ. Collectively, our study reveals that NRP-1 enhances TMZ resistance in GBM possibly by regulating the STAT1/p53/p21 axis.

RACK1 promotes the occurrence and progression of cervical carcinoma

BACKGROUND

RACK1 has been identified as a multifunctional cytosolic protein, and plays a pivotal role in multiple biological responses involved in several kinds of tumors, while its effect in cervical cancer has not been well elucidated yet. The study aimed to investigate the role of RACK1 in cervical cancer occurrence and progression.

METHODS

The expression of RACK1 in cervical specimens was measured by immunohistochemical staining and Western blot assay. Transgenic mice were used to detect the role of RACK1 in modulating tumorigenesis in vivo. Cervical carcinoma cell lines were used to explore the underlying mechanisms of RACK1 on the behaviors of tumor cells in vitro.

RESULTS

We found that RACK1 expression was upregulated in cancer tissues compared with adjacent tissues, and its expression was gradually increased from cervictis, and cervical intraepithelial neoplasis (CIN) to carcinoma. Genetic overexpression of RACK1 facilitated tumor formation and growth in nude mice. Mechanism studies disclosed that RACK1 over-expression prolonged the G0 /G1 phase by up-regulating the expression of cyclinD1, down-regulating p21 and p27 probably by modulating the phosphorylation of AKT.

CONCLUSIONS

Taken together, we concluded that RACK1 stimulates tumorigenesis and progression of cervical cancer via modulating the proliferation of tumor cells, implying that targeting RACK1 may serve as a promising method for cervical cancer therapy.

Species-specific FMRP regulation of RACK1 is critical for prenatal cortical development

Fragile X messenger ribonucleoprotein 1 protein (FMRP) deficiency leads to fragile X syndrome (FXS), an autism spectrum disorder. The role of FMRP in prenatal human brain development remains unclear. Here, we show that FMRP is important for human and macaque prenatal brain development. Both FMRP-deficient neurons in human fetal cortical slices and FXS patient stem cell-derived neurons exhibit mitochondrial dysfunctions and hyperexcitability. Using multiomics analyses, we have identified both FMRP-bound mRNAs and FMRP-interacting proteins in human neurons and unveiled a previously unknown role of FMRP in regulating essential genes during human prenatal development. We demonstrate that FMRP interaction with CNOT1 maintains the levels of receptor for activated C kinase 1 (RACK1), a species-specific FMRP target. Genetic reduction of RACK1 leads to both mitochondrial dysfunctions and hyperexcitability, resembling FXS neurons. Finally, enhancing mitochondrial functions rescues deficits of FMRP-deficient cortical neurons during prenatal development, demonstrating targeting mitochondrial dysfunction as a potential treatment.

OTUB1's role in promoting OSCC development by stabilizing RACK1 involves cell proliferation, migration, invasion, and tumor-associated macrophage M1 polarization

Ovarian tumor domain, ubiquitin aldehyde binding 1 (OTUB1), a deubiquitinating enzyme known to regulate the stability of downstream proteins, has been reported to regulate various cancers tumorigenesis, yet its direct effects on oral squamous cell carcinoma (OSCC) progression are unclear. Bioinformatics analysis was performed to screen for genes of interest, and in vitro and in vivo studies were carried out to investigate the function and mechanism of OTUB1 in OSCC. We found that OTUB1 was abnormally elevated in OSCC tissues and positively associated with the pathological stage and tumor stage. Knockdown of OTUB1 impaired the malignance of OSCC cells - suppressed cell proliferation, invasion, migration, and xenografted tumor growth. OTUB1 silencing also drove tumor-associated macrophage M1 polarization but suppressed M2 polarization, and the induction of M1 polarization inhibited the survival of OSCC cells. However, OTUB1 overexpression exerted the opposite effects. Furthermore, the protein network that interacted with the OTUB1 protein was constructed based on the GeneMANIA website. Receptor for activated C kinase 1 (RACK1), a facilitator of OSCC progression, was identified as a potential target of the OTUB1 protein. We revealed that OTUB1 positively regulated RACK1 expression and inhibited RACK1 ubiquitination. Additionally, RACK1 upregulation reversed the effects of OTUB1 knockdown on OSCC progression. Overall, we demonstrated that OTUB1 might regulate OSCC progression by maintaining the stability of the RACK1 protein. These findings highlight the potential roles of the OTUB1/RACK1 axis as a potential therapeutic target in OSCC.

Characterization of RACK1-depleted mammalian cells by a palette of microscopy approaches reveals defects in cell cycle progression and polarity establishment

The Receptor for Activated C Kinase 1 (RACK1) is an evolutionarily conserved scaffold protein involved in the regulation of numerous cellular processes. Here, we used CRISPR/Cas9 and siRNA to reduce the expression of RACK1 in Madin-Darby Canine Kidney (MDCK) epithelial cells and Rat2 fibroblasts, respectively. RACK1-depleted cells were examined using coherence-controlled holographic microscopy, immunofluorescence, and electron microscopy. RACK1 depletion resulted in decreased cell proliferation, increased cell area and perimeter, and in the appearance of large binucleated cells suggesting a defect in the cell cycle progression. Our results show that the depletion of RACK1 has a pleiotropic effect on both epithelial and mesenchymal cell lines and support its essential role in mammalian cells.

Molecular Mechanism of Malignant Transformation of Balb/c-3T3 Cells Induced by Long-Term Exposure to 1800 MHz Radiofrequency Electromagnetic Radiation (RF-EMR)

Purpose: We aimed to investigate RF-EMR-induced cell malignant transformation. Methods: We divided Balb/c-3T3 cells into sham and expo groups. The expo groups were exposed to a 1800 MHz RF continuous wave for 40 and 60 days, for 4 h per day. The sham group was sham-exposed. Cells were harvested for a cell transformation assay, transplantation in severe combined immune deficient (SCID) mice, soft agar clone formation detection, and a transwell assay. The mRNA microarray assay was used to declare key genes and pathways. Results: The exposed Balb/c-3T3 cells showed a strong increase in cell proliferation and migration. Malignant transformation was observed in expo Balb/c-3T3 cells exposed for 40 days and 60 days, which was symbolized with visible foci and clone formation. Expo Balb/c-3T3 cells that were exposed for 40 days and 60 days produced visible tumors in the SCID mice. Lipid metabolism was the key biological process and pathway involved. The mevalonate (MVA) pathway was the key metabolic pathway. The interacted miRNAs could be further research targets to examine the molecular mechanism of the carcinogenic effects of long-term exposure. Conclusion: Exposure for 40 and 60 days to 1800 MHz RF-EMR induced malignant transformation in Balb/c-3T3 cells at the SAR of 8.0 W/kg. We declared that lipid metabolism was the pivotal biological process and pathway. The MVA pathway was the key metabolic pathway.

Human bone marrow mesenchymal stem cell-derived extracellular vesicles impede the progression of cervical cancer via the miR-144-3p/CEP55 pathway

Cervical cancer is the most common gynaecological malignancy, with a high incidence rate and mortality rate in middle‐aged women. Human bone marrow mesenchymal stem cells (hBMSCs) have been implicated in the initiation and subsequent development of cancer, along with the involvement of extracellular vesicles (EVs) mediating intracellular communication by delivering microRNAs (miRNAs or miRs). This study is aimed at investigating the physiological mechanisms by which EVs‐encapsulated miR‐144‐3p derived from hBMSCs might mediate the progression of cervical cancer. The expression profiles of centrosomal protein, 55 Kd (CEP55) and miR‐144‐3p in cervical cancer cell lines and tissues, were quantified by RT‐qPCR and Western blot analysis. The binding affinity between miR‐144‐3p and CEP55 was identified using in silico analysis and luciferase activity determination. Cervical cancer cells were co‐cultured with EVs derived from hBMSCs that were treated with either miR‐144‐3p mimic or miR‐144‐3p inhibitor. Cervical cancer cell proliferation, invasion, migration and apoptosis were detected in vitro. The effects of hBMSCs‐miR‐144‐3p on tumour growth were also investigated in vivo. miR‐144‐3p was down‐regulated, whereas CEP55 was up‐regulated in cervical cancer cell lines and tissues. CEP55 was targeted by miR‐144‐3p, which suppressed cervical cancer cell proliferation, invasion and migration and promoted apoptosis via CEP55. Furthermore, similar results were obtained by hBMSCs‐derived EVs carrying miR‐144‐3p. In vivo assays confirmed the tumour‐suppressive effects of miR‐144‐3p in hBMSCs‐derived EVs on cervical cancer. Collectively, hBMSCs‐derived EVs‐loaded miR‐144‐3p impedes the development and progression of cervical cancer through target inhibition of CEP55, therefore providing us with a potential therapeutic target for treating cervical cancer.

The role of RNA-binding and ribosomal proteins as specific RNA translation regulators in cellular differentiation and carcinogenesis

Tight control of mRNA expression is required for cell differentiation; imbalanced regulation may lead to developmental disorders and cancer. The activity of the translational machinery (including ribosomes and translation factors) regulates the rate (slow or fast) of translation of encoded proteins, and the quality of these proteins highly depends on which mRNAs are available for translation. Specific RNA-binding and ribosomal proteins seem to play a key role in controlling gene expression to determine the differentiation fate of the cell. This demonstrates the important role of RNA-binding proteins, specific ribosome-binding proteins and microRNAs as key molecules in controlling the specific proteins required for the differentiation or dedifferentiation of cells. This delicate balance between specific proteins (in terms of quality and availability) and post-translational modifications occurring in the cytoplasm is crucial for cell differentiation, dedifferentiation and oncogenic potential. In this review, we report how defects in the regulation of mRNA translation can be dependent on specific proteins and can induce an imbalance between differentiation and dedifferentiation in cell fate determination.

RACK1 promotes miR-302b/c/d-3p expression and inhibits CCNO expression to induce cell apoptosis in cervical squamous cell carcinoma

Background

Cervical squamous cell carcinoma (CSCC) is one of the main causes of cancer-related deaths in women worldwide. The present study was conducted with the main objective of determining the potential role of receptor for activated protein kinase C1 (RACK1) in CSCC through regulation of microRNA (miR)-302b/c/d-3p and Cyclin O (CCNO).

Methods

The expression of RACK1, miR-302b/c/d-3p and CCNO in CSCC tissues and cells was measured by RT-qPCR and Western blot analysis. The interaction among RACK1, miR-302b/c/d-3p, and CCNO was determined by dual luciferase reporter assay. Subsequently, effects of RACK1, miR-302b/c/d-3p and CCNO on CSCC cell cycle entry, proliferation and apoptosis were investigated with the use of flow cytometry, EdU, and TUNEL assays. Furthermore, mouse xenograft model of CSCC cells was established to verify the function of RACK1 in vivo.

Results

RACK1 and miR-302b/c/d-3p were down-regulated and CCNO was overexpressed in CSCC. CCNO was identified as the target of miR-302b/c/d-3p. Importantly, overexpressed miR-302b-3p, miR-302c-3p or miR-302d-3p or RACK1 enhanced the apoptosis and suppressed the proliferation of CSCC cells in vitro, while inhibiting tumor growth in vivo by targeting CCNO.

Conclusions

On all accounts, overexpressed RACK1 could dampen the progression of CSCC through miR-302b/c/d-3p-mediated CCNO inhibition.

Complementary Targeting of Rb Phosphorylation and Growth in Cervical Cancer Cell Cultures and a Xenograft Mouse Model by SHetA2 and Palbociclib

Cervical cancer is caused by high-risk human papillomavirus (HPV) types and treated with conventional chemotherapy with surgery and/or radiation. HPV E6 and E7 proteins increase phosphorylation of retinoblastoma (Rb) by cyclin D1/cyclin dependent kinase (CDK)4/6 complexes. We hypothesized that cyclin D1 degradation by the SHetA2 drug in combination with palbociclib inhibition of CDK4/6 activity synergistically reduces phosphorylated Rb (phospho-Rb) and inhibits cervical cancer growth. The effects of these drugs, alone, and in combination, were evaluated in SiHa and CaSki HPV-positive and C33A HPV-negative cervical cancer cell lines using cell culture, western blots and ELISA, and in a SiHa xenograft model. Endpoints were compared by isobolograms, ANOVA, and Chi-Square. In all cell lines, combination indexes documented synergistic interaction of SHetA2 and palbociclib in association SHetA2 reduction of cyclin D1 and phospho-Rb, palbociclib reduction of phospho-Rb, and enhanced phospho-Rb reduction upon drug combination. Both drugs significantly reduced phospho-Rb and growth of SiHa xenograft tumors as single agents and acted additively when combined, with no evidence of toxicity. Dilated CD31-negative blood vessels adjacent to, or within, areas of necrosis and apoptosis were observed in all drug-treated tumors. These results justify development of the SHetA2 and palbociclib combination for targeting phospho-Rb in cervical cancer treatment.

Long noncoding RNA ZFAS1 promotes tumorigenesis and metastasis in nasopharyngeal carcinoma by sponging miR-892b to up-regulate LPAR1 expression

OBJECTIVE

In this study, we explored the NPC-specific expression of ZFAS1 and the mechanism of ZFAS1-mediated growth, aggressiveness and tumorigenesis in NPC.

METHODS

The expression profile of lncRNAs was detected in NPC tissues and matching para-carcinoma tissues using microarray analysis. LncRNA-miRNA and miRNA-mRNA interaction networks were constructed using the miRcode v11 and TargetScanHuman v7.2 web server and then validated using dual-luciferase assay. Western blot and RT-qPCR were performed to detect protein and RNA expression. The effects of ZFAS1, miR-892b and LPAR1 dysregulation on the proliferative, migratory and invasive abilities of NPC cells were observed using colony formation, cell counting kit-8 (CCK-8) and transwell assays in vitro. In vivo, a xenograft nude mouse model was established to detect the impact of ZFAS1 dysregulation on the tumorigenicity of NPC cells.

RESULTS

The expression of multiple lncRNAs, of which ZFAS1 was up-regulated, was dysregulated in NPC tissues. ZFAS1 directly targeted miR-892b, and miR-892b negatively regulated the expression of downstream LPAR1. The proliferation, migration and invasion of NPC cells could be largely enhanced by the downregulation of miR-892b as well as the up-regulation of ZFAS1 and LPAR1, while the overexpression of miR-892b and the downregulation of ZFAS1 and LPAR1 decreased these abilities. In nude mice, the growth of tumour xenografts formed by HONE1 cells was significantly suppressed when ZFAS1 was silenced.

CONCLUSION

The study demonstrated that lncRNA ZFAS1 may act as a promoter of tumorigenesis and metastasis in nasopharyngeal carcinoma, by up-regulating the expression of LPAR1 in a miR-892b-dependent manner.

p38-regulated FOXC1 stability is required for colorectal cancer metastasis

Aberrant expression of forkhead box C1 (FOXC1) promotes tumor metastasis in multiple human malignant tumors. However, the upstream modulating mode and downstream molecular mechanism of FOXC1 in metastasis of colorectal cancer (CRC) remain unclear. Herein we describe a systematic analysis of FOXC1 expression and prognosis in CRC performed on our clinical data and public databases, which indicated that FOXC1 upregulation in CRC samples was significantly associated with poor prognosis. FOXC1 knockdown inhibited migration and invasion, whereas FOXC1 overexpression caused the opposite phenotype in vitro and in vivo. Furthermore, MMP10, SOX4 and SOX13 were verified as the target genes of FOXC1 for promoting CRC metastasis. MMP10 was demonstrated as the direct target and mediator of FOXC1. Interestingly, Ser241 and Ser272 of FOXC1 were identified as the key sites to interact with p38 and phosphorylation, which were critically required for maintaining the stability of FOXC1 protein. Moreover, FOXC1 was dephosphorylated by protein phosphatase 2A and phosphorylated by p38, which maintained FOXC1 protein stability through inhibiting ubiquitination. Expression of p38 was correlated with FOXC1 and MMP10 expression, indirectly indicating that FOXC1 was regulated by p38 MAPK. Therefore, FOXC1 is strongly suggested as a pro-metastatic gene in CRC by transcriptionally activating MMP10, SOX4 and SOX13; p38 interacts with and phosphorylates the Ser241 and ser272 sites of FOXC1 to maintain its stability by inhibiting ubiquitination and degradation. In conclusion, the protein stability of FOXC1 mediated by p38 contributes to the metastatic effect in CRC. © 2019 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Taurine-upregulated gene 1 contributes to cancers through sponging microRNA

Long non-coding RNAs (lncRNAs) are a class of RNAs whose transcripts are more than 200 nucleotides in length and lack protein-coding ability. Taurine-upregulated gene 1 (TUG1), a novel cancer-related lncRNA, has been documented to be abnormally expressed in various types of cancers and act as an oncogene or anti-oncogene. It has been considered previously that TUG1 is closely related to the cell proliferation, invasion, metastasis, and apoptosis of cancer. In recent years, it has been found that TUG1 acts as a microRNA (miRNA) sponge to indirectly regulate the expression of the miRNA target gene and dominates cancer progression in several types of cancers. However, TUG1 also binds to different miRNAs to produce diverse regulatory mechanisms in the same cancer. TUG1 is expected to be a biomarker and a new therapeutic target for the diagnosis and prognosis of certain cancers. In this review, we highlight the up-to-date original studies that focus on the role of TUG1 sponging miRNA in cancers and summarize the function of TUG1 in cancer progression. The novel TUG1-miRNA regulatory network is comprehensively and minutely included in this review. We hope that this review will help readers obtain a more detailed knowledge of the molecular mechanism by which TUG1 sponging miRNA plays its role in cancers, and provide some insights and directions for future cancer research.

CD38 affects the biological behavior and energy metabolism of nasopharyngeal carcinoma cells

Nasopharyngeal carcinoma (NPC) is the most common malignant tumor type in Southern China and South-East Asia. Cluster of differentiation (CD)38 is highly expressed in the human immune system and participates in the activation of T, natural killer and plasma cells mediated by CD2 and CD3 through synergistic action. CD38 is a type II transmembrane glycoprotein, which was observed to mediate diverse activities, including signal transduction, cell adhesion and cyclic ADP-ribose synthesis. However, the significance of CD38 in NPC biological behavior and cellular energy metabolism has not been examined. In order to elucidate the effect of CD38 on the biological behavior of NPC cells, stable CD38-overexpressed NPC cell lines were established. It was demonstrated that CD38 promoted NPC cell proliferation with Cell Counting Kit-8 and colony formation assays. It was also indicated that CD38 inhibited cell senescence, and promoted cell metastasis. Furthermore, it was determined that CD38 promoted the conversion of cells to the S phase and decreased the content of reactive oxygen species and Ca²⁺. Additionally, cell metabolism assays demonstrated that CD38 increased the concentration of ATP, lactic acid, cyclic adenosine monophosphate and human ADP/acrp30 concentration in NPC cells. To investigate the possible mechanism, bioinformatics analysis and mass spectrometry technology was used to determine the most notably changing molecule and signaling pathways, and it was determined and verified that CD38 regulated the metabolic-associated signaling pathways associated with tumor protein 53, hypoxia inducible factor-1α and sirtuin 1. The present results indicated that CD38 may serve a carcinogenic role in NPC by regulating metabolic-associated signaling pathways.

SMAGP a novel biomarker of cervical cancer development and progression

Introduction

Cervical cancer, one of the most common malignant gynecological tumors, is a significant burden on the health of females worldwide. The purpose of this study was to investigate genes associated with lymph node metastasis in cervical cancer.

Methods

We report on the lymph node metastasis-associated gene, small cell adhesion glycoprotein (SMAGP), as a key regulator of cervical cancer development and progression. SMAGP expression levels were investigated in 70 cervical squamous cell carcinoma samples and 10 normal cervical squamous epithelium samples.

Results

Immunohistochemistry analysis revealed that SMAGP protein levels were significantly elevated in cervical cancer tissue compared with normal cervical squamous epithelium. Silencing of SMAGP induced cell cycle arrest, inhibited the cell proliferation and colony formation ability of cervical cancer cells in vitro and suppressed their tumorigenic potential in nude mice. In addition, SMAGP knockdown reduced expression of epithelial mesenchymal transition-related proteins, including vimentin, β-cadherin, MMP2, and Twist.

Conclusion

Together, our findings demonstrate that SMAGP plays a critical role in cell proliferation and tumorigenesis and could be a new therapeutic target in cervical cancer.