MicroRNA-204 inhibits the proliferation, migration and invasion of human lung cancer cells by targeting PCNA-1 and inhibits tumor growth in vivo

Anti-proliferative and apoptotic effect of cannabinoids on human pancreatic ductal adenocarcinoma xenograft in BALB/c nude mice model

Human pancreatic ductal adenocarcinoma (PDAC) is a highly malignant and lethal tumor of the exocrine pancreas. Cannabinoids extracted from the hemp plant Cannabis sativa have been suggested as a potential therapeutic agent in several human tumors. However, the anti-tumor effect of cannabinoids on human PDAC is not entirely clarified. In this study, the anti-proliferative and apoptotic effect of cannabinoid solution (THC:CBD at 1:6) at a dose of 1, 5, and 10 mg/kg body weight compared to the negative control (sesame oil) and positive control (5-fluorouracil) was investigated in human PDAC xenograft nude mice model. The findings showed that cannabinoids significantly decreased the mitotic cells and mitotic/apoptotic ratio, meanwhile dramatically increased the apoptotic cells. Parallelly, cannabinoids significantly downregulated Ki-67 and PCNA expression levels. Interestingly, cannabinoids upregulated BAX, BAX/BCL-2 ratio, and Caspase-3, meanwhile, downregulated BCL-2 expression level and could not change Caspase-8 expression level. These findings suggest that cannabinoid solution (THC:CBD at 1:6) could inhibit proliferation and induce apoptosis in human PDAC xenograft models. Cannabinoids, including THC:CBD, should be further studied for use as the potent PDCA therapeutic agent in humans.

PRIM2 Promotes Cell Cycle and Tumor Progression in p53-Mutant Lung Cancer

Simple Summary

The mutation or inactivation of tumor suppressor genes is a key driving force during tumorigenesis, among which, p53 mutation is a common feature of human cancer. Therefore, exploring the potential role of p53 mutation in the occurrence and development of tumors is a powerful support for tumor diagnosis and treatment. In this study, we found that PRIM2 expression was abnormally elevated in p53-mutated lung cancer patients, and the elevated PRIM2 promoted DNA replication, enhanced mismatch repair, activated cell cycle, and promoted lung cancer progression. Here, we first report that the expression of PRIM2 is regulated by p53, and is identified as a biomarker of lung cancer malignancy and survival prognosis.

Abstract

p53 is a common tumor suppressor, and its mutation drives tumorigenesis. What is more, p53 mutations have also been reported to be indicative of poor prognosis in lung cancer, but the detailed mechanism has not been elucidated. In this study, we found that DNA primase subunit 2 (PRIM2) had a high expression level and associated with poor prognosis in lung cancer. Furthermore, we found that PRIM2 expression was abnormally increased in lung cancer cells with p53 mutation or altered the p53/RB pathway based on database. We also verified that PRIM2 expression was elevated by mutation or deletion of p53 in lung cancer cell lines. Lastly, silence p53 increased the expression of RPIM2. Thus, these data suggest that PRIM2 is a cancer-promoting factor which is regulated by the p53/RB pathway. The p53 tumor-suppressor gene integrates numerous signals that control cell proliferation, cell cycle, and cell death; and the p53/RB pathway determines the cellular localization of transcription factor E2F, which regulates the expression of downstream targets. Next, we explored the role of PRIM2 in lung cancer and found that knockdown of PRIM2 induced cell cycle arrest, increased DNA damage, and increased cell senescence, leading to decreased lung cancer cell proliferation. Lastly, the positive correlation between PRIM2 and E2F/CDK also indicated that PRIM2 was involved in promoting cell cycle mediated by p53/RB pathway. These results confirmed that the expression of PRIM2 is regulated by the p53/RB pathway in lung cancer cells, promotes DNA replication and mismatch repair, and activates the cell cycle. Overall, we found that frequent p53 mutations increased PRIM2 expression, activated the cell cycle, and promoted lung cancer progression.

miRNAs through β-ARR2/p-ERK1/2 pathway regulate the VSMC proliferation and migration

BACKGROUND

miRNAs are involved in plaque formation of atherosclerosis and vessel restenosis. In this study, we investigated the effects of miR-599, miR-204, and miR-181b on VSMC proliferation, and migration through TGFβ receptor 2 (TGFβR2), β-arrestin 2 (β-ARR2), SMAD2/p-SMAD2, and ERK1/2/p-ERK1/2.

MATERIALS & METHODS

Genes and miRNAs were predicted by bioinformatics tools and were transfected by PEI-miRNAs (miR-599, miR-204, and miR-181b) complexes into VSMCs. The gene and protein expression levels were evaluated by real-time RT-PCR and western blotting techniques, respectively. The VSMC proliferation and migration were studied by MTT and scratch assay, respectively.

RESULTS

The miR-181b and miR-204 downregulated significantly β-ARR2 gene and protein expression levels and p-ERK1/2 values. Moreover, TGFβR2 gene and protein expression levels and p-SMAD2 values were not significantly affected by miR-181b and miR-204. The VSMC proliferation (p = 0.0019, p = 0.0054, respectively) and migration (p < 0.0001, p < 0.0001, respectively) were inhibited by the miR-181b and miR-204. The miR-599 inhibited VSMC proliferation (p = 0.044) and migration (p = 0.0055) but it did not affect significantly the β-ARR2 and TGFβR2 gene and protein expression levels.

CONCLUSION

The results suggested that the inhibitory effects of miR-181b and miR-204 on VSMC proliferation and migration are mediated by the β-ARR2/p-ERK1/2 pathway. Since VSMC proliferation and migration are involved in plaque growth, therefore this pathway can be a therapeutic target for atherosclerosis.

MicroRNA-204 plays a role as a tumor suppressor in Newcastle disease virus-induced oncolysis in lung cancer A549 cells

Tumor development and progression are closely associated with various microRNAs (miRNAs/miRs). We have previously shown that Newcastle disease virus (NDV) strain 7793 induces oncolysis in lung cancer. However, how NDV exerts its oncolytic effect on lung cancer remains to be investigated. The present study assessed the role of miR-204 in the NDV-induced oncolysis of lung cancer A549 cells by oncolysis induction in vitro. miR-204 was significantly upregulated in NDV-treated A549 cells. Overexpression or inhibition of miR-204 was significantly associated with NDV-induced oncolysis in A549 cells. Caspase-3 and Bax, major regulators of the apoptosis pathway, were regulated by miR-204, and the association between caspase-3-related apoptosis and miR-204 was identified in NDV-mediated oncolysis. These data demonstrated that miR-204 as a tumor suppressor played a role in NDV-induced oncolysis in lung cancer cells. The present study demonstrates the potential of strategies using miRs to improve oncolytic NDV potency, and highlights miR-204 as a tumor suppressor in NDV-induced oncolysis of lung cancer cells.

lncRNA TPTEP1 inhibits stemness and radioresistance of glioma through miR‑106a‑5p‑mediated P38 MAPK signaling

Glioma is diagnosed as the most common intracranial malignant tumor. Cancer stem cells determine stemness and radioresistance, and may facilitate glioma recurrence. The present study aimed to investigate whether the long non-coding RNA (lncRNA) transmembrane phosphatase with tensin homology pseudogene 1 (TPTEP1) regulated cell stemness and radioresistance of glioma, and determine the underlying molecular mechanism of TPTEP1 in the modulation of glioma progression. Cell and molecular biology techniques were applied for investigating the role of TPTEP1 in glioma cell lines, animal model, and clinical samples. The results demonstrated that TPTEP1 attenuated stemness and radioresistance of glioma both in vitro and in vivo. In addition, TPTEP1 augmented MAPK14 expression by competitively interacting with microRNA (miR)-106a-5p, thus activating the P38 MAPK signaling pathway, and suppressing glioma stemness and radioresistance. TPTEP1 functionally bound to miR-106a-5p, which formed a reciprocal regulatory loop to stimulate the P38 MAPK signaling pathway. Low TPTEP1 expression levels were detected in high-grade glioma tissues compared with low-grade glioma tissues, and were positively associated with poor prognosis of patients with glioma. Furthermore, analysis using data from The Cancer Genome Atlas database confirmed the molecular mechanism and biological significance of dysregulation of TPTEP1 in glioma progression. Taken together, the results of the present study suggest that TPTEP1 may be applied as a diagnostic and prognostic indicator for glioma, and may be an alternative target for the treatment of glioma.

Knockdown of the long noncoding RNA XIST suppresses glioma progression by upregulating miR-204-5p

Background: Gliomas are the most prevalent primary malignant tumors of the central nervous system. Our previous study showed that miR-204-5p is a tumor suppressor gene in glioma. Bioinformatic analyses suggest that long noncoding RNA (lncRNA) X-inactive specific transcript (XIST) is a potential target gene of miR-204-5p.

Methods: We analyzed the expression of XIST and miR-204-5p in glioma tissues and the correlation with glioma grade. A series of in vitro experiments were carried out to elucidate the role of XIST in glioma progression. A mouse xenograft model was established to detect whether knockdown of XIST can inhibit glioma growth. A luciferase assay was performed to determine whether XIST can bind to miR-204-5p and the binding specificity. Cells stably expressing shXIST or shNC were transfected with anti-miR-204-5p or anti-miR-204-5p-NC to evaluate whether XIST mediates the tumor-suppressive effects of miR-204-5p.

Results: XIST was upregulated in glioma tissues compared with normal brain tissues (NBTs), while miR-204-5p expression was significantly decreased in glioma tissues compared with NBTs. Both XIST and miR-204-5p expression levels were clearly related to glioma grade, and the expression of XIST was obviously negatively correlated with miR-204-5p expression. Knockdown of XIST inhibited glioma cell proliferation, migration, and invasion, promoted apoptosis of glioma cells, inhibited tumor growth and increased the survival time in nude mice. miR-204-5p could directly bind to XIST and negatively regulate XIST expression. XIST mediated glioma progression by targeting miR-204-5p in glioma cells. XIST crosstalk with miR-204-5p regulated Bcl-2 expression to promote apoptosis.

Conclusion: Our results provide evidence that XIST, miR-204-5p and Bcl-2 form a regulatory axis that controls glioma progression and can serve as a potential therapeutic target for glioma.

MicroRNAs as Theranostics Targets in Oral Carcinoma Stem Cells

Oral cancer belongs to head and neck squamous cell carcinoma and has been recognized as one of the most prevalent malignancies worldwide. Recent studies have suggested that cancer stem cells (CSCs) may participate in tumor initiation, metastasis and even recurrence, so the regulation of CSCs has drawn significant attention over the past decade. Among various molecules that are associated with CSCs, non-coding RNAs (ncRNAs) have been indicated as key players in the acquisition and maintenance of cancer stemness. In addition, accumulating studies have shown that the aberrant expression of these ncRNAs may serve as surrogate diagnostic markers or even therapeutic targets for cancer treatment. The current study reviews the previous work by us and others to summarize how these ncRNAs affect oral cancer stemness and their potential theranostic applications. A better understanding of the implication of these ncRNAs in oral tumorigenesis will facilitate the translation of basic ncRNA research into clinical application in the future.

MicroRNA Dysregulation in Cutaneous Squamous Cell Carcinoma

Cutaneous squamous cell carcinoma (CSCC) is the second most frequent cancer in humans and it can be locally invasive and metastatic to distant sites. MicroRNAs (miRNAs or miRs) are endogenous, small, non-coding RNAs of 19–25 nucleotides in length, that are involved in regulating gene expression at a post-transcriptional level. MicroRNAs have been implicated in diverse biological functions and diseases. In cancer, miRNAs can proceed either as oncogenic miRNAs (onco-miRs) or as tumor suppressor miRNAs (oncosuppressor-miRs), depending on the pathway in which they are involved. Dysregulation of miRNA expression has been shown in most of the tumors evaluated. MiRNA dysregulation is known to be involved in the development of cutaneous squamous cell carcinoma (CSCC). In this review, we focus on the recent evidence about the role of miRNAs in the development of CSCC and in the prognosis of this form of skin cancer.