The phosphoinositide hydrolase phospholipase C delta1 inhibits epithelial-mesenchymal transition and is silenced in colorectal cancer

MicroRNA-191 regulates oral squamous cell carcinoma cells growth by targeting PLCD1 via the Wnt/β-catenin signaling pathway

BACKGROUND

Studies have shown that microRNA-191 (miR-191) is involved in the development and progression of a variety of tumors. However, the function and mechanism of miR-191 in oral squamous cell carcinoma (OSCC) have not been clarified.

METHODS

The expression level of miR-191 in tumor tissues of patients with primary OSCC and OSCC cell lines were detected using real-time quantitative polymerase chain reaction (RT-qPCR) and western blot. OSCC cells were treated with miR-191 enhancers and inhibitors to investigate the effects of elevated or decreased miR-191 expression on OSCC cells proliferation, migration, cell cycle, and tumorigenesis. The target gene of miR-191 in OSCC cells were analyzed by dual-Luciferase assay, and the downstream signaling pathway of the target genes was detected using western blot assay.

RESULTS

The expression of miR-191 was significantly upregulated in OSCC tissues and cell lines. Upregulation of miR-191 promoted proliferation, migration, invasion, and cell cycle progression of OSCC cells, as well as tumor growth in nude mice. Meanwhile, reduced expression of miR-191 inhibited these processes. Phospholipase C delta1 (PLCD1) expression was significantly downregulated, and negatively correlated with the expression of miR-191 in OSCC tissues. Dual-Luciferase assays showed that miR-191-5p could bind to PLCD1 mRNA and regulate PLCD1 protein expression. Western blot assay showed that the miR-191 regulated the expression of β-catenin and its downstream gene through targeting PLCD1.

CONCLUSION

MicroRNA-191 regulates oral squamous cell carcinoma cells growth by targeting PLCD1 via the Wnt/β-catenin signaling pathway. Thus, miR-191 may serve as a potential target for the treatment of OSCC.

lncRNA MIR503HG Targets miR-191-5p/PLCD1 Axis and Negatively Modulates Apoptosis, Extracellular Matrix Disruption, and Inflammation in Abdominal Aortic Aneurysm

As the most prevalent subtype of aortic aneurysm, abdominal aortic aneurysm (AAA) features the apoptosis, extracellular matrix (ECM) disruption, and inflammation response of vascular smooth muscle cells (VSMCs). Noncoding RNAs (ncRNAs) are crucial factors in AAA progression, while the investigations have not been fully explained. miR-191-5p upregulation is found in aortic aneurysm. However, its role in AAA has not been addressed. This research purposed to excavate the possible and associated molecular axis of miR-191-5p in AAA. In our study, miR-191-5p level was detected to be high in the tissues from AAA patients in comparison with the control group. After miR-191-5p expression was enhanced, cell viability was repressed, cell apoptosis was boosted, and ECM disruption and the inflammation response were fortified. Furthermore, the relationship among MIR503HG, miR-191-5p, and phospholipase C delta 1 (PLCD1) in VSMCs was disclosed via mechanism assays. Decreased MIR503HG lacked the inhibition on miR-191-5p targeting PLCD1, resulting in downregulation of PLCD1, which facilitated the progression of AAA. Thus, targeting MIR503HG/miR-191-5p/PLCD1 pathway will provide an additional method for the cure of AAA patients.

MiR-17-3p Facilitates Aggressive Cell Phenotypes in Colon Cancer by Targeting PLCD1 Through Affecting KIF14

Colon cancer (CC) is a common and lethal cancer to be further elucidated. Accumulating studies elaborated the crucial role of miRNAs differentially expressed in cancer cell growth. In the present study, differentially expressed miRNAs related to CC were screened by the bioinformatics methods on the strength of TCGA database. Highly expressed miR-17-3p was proved to notably influence CC cell proliferative, migratory, invasion, and apoptotic levels. By using TargetScan and miRTarBase databases, phospholipase C delta 1 (PLCD1) was predicted as a target downstream of miR-17-3p, and their binding site was predicted. Through TCGA database, low expression of PLCD1 and its significant negative correlation with miR-17-3p were identified in CC. Dual-luciferase reporter gene analysis ascertained the targeting relationship between miR-17-3p and PLCD1. Cell Counting Kit-8, colony formation, and transwell assays were introduced to detect CC cell malignant progression. Flow cytometry was applied to detect CC cell apoptosis. As result revealed, miR-17-3p was markedly highly expressed, and PLCD1, the target of miR-17-3p, was remarkably lowly expressed in CC cells. Forced expression of miR-17-3p facilitated CC cell proliferation, migration, invasion, and suppressed apoptosis. Biological roles of upregulating miR-17-3p in the colon cancer cells were markedly weakened by over-expressing PLCD1 simultaneously. MiR-17-3p regulated CC cell malignant progression, as well as apoptosis by targeting PLCD1. Moreover, KIF14 was extensively considered as an involved tumor-promoting gene that could be affected by miR-17-3p/PLCD1 axis based on BioGRID analysis and CO-IP assay. Concludingly, this study exhibited that miR-17-3p facilitated CC progression by PLCD1 downregulation.

Phospholipase C delta 1 inhibits WNT/β-catenin and EGFR-FAK-ERK signaling and is disrupted by promoter CpG methylation in renal cell carcinoma

BACKGROUND

PLCD1, located at 3p22, encodes an enzyme that mediates cellular metabolism and homeostasis, intracellular signal transduction and movement. PLCD1 plays a pivotal role in tumor suppression of several types of cancers; however, its expression and underlying molecular mechanisms in renal cell carcinoma (RCC) pathogenesis remain elusive.

METHODS

RT-PCR and Western blot were used to detect PLCD1 expression in RCC cell lines and normal tissues. Bisulfite treatment, MSP and BGS were utilized to explore the CpG methylation status of PLCD1 promoter. Online databases were analyzed for the association between PLCD1 expression/methylation and patient survival. In vitro experiments including CCK8, colony formation, wound-healing, transwell migration and invasion, immunofluorescence and flow cytometry assays were performed to evaluate tumor cell behavior. Luciferase assay and Western blot were used to examine effect of PLCD1 on WNT/β-catenin and EGFR-FAK-ERK signaling.

RESULTS

We found that PLCD1 was widely expressed in multiple adult normal tissues including kidney, but frequently downregulated or silenced in RCC due to its promoter CpG methylation. Restoration of PLCD1 expression inhibited the viability, migration and induced G2/M cell cycle arrest and apoptosis in RCC cells. PLCD1 restoration led to the inhibition of signaling activation of WNT/β-catenin and EGFR-FAK-ERK pathways, and the EMT program of RCC cells.

CONCLUSIONS

Our results demonstrate that PLCD1 is a potent tumor suppressor frequently inactivated by promoter methylation in RCC and exerts its tumor suppressive functions via suppressing WNT/β-catenin and EGFR-FAK-ERK signaling. These findings establish PLCD1 as a promising prognostic biomarker and treatment target for RCC.

Origin recognition complex 1 regulates phospholipase Cδ1 to inhibit cell proliferation, migration and epithelial-mesenchymal transition in lung adenocarcinoma

As a common pulmonary malignant disease, lung adenocarcinoma exhibits high mortality and morbidity rate. Phospholipase Cδ1 (PLCD1), an enzyme involved in the homeostasis of energy metabolism, is downregulated in lung adenocarcinoma. According to GEPIA, origin recognition complex 1 (ORC1) is a highly expressed gene in lung adenocarcinoma and is negatively associated with PLCD1. To the best of our knowledge, the present study was the first to investigate the role of ORC1 in regulating PLCD1 in lung adenocarcinoma. According to TCGA database, low expression of PLCD1 was correlated with the low overall survival rate of patients suffering from lung adenocarcinoma. The protein and mRNA expression levels of PLCD1 and ORC1 were detected in A549 cells by western blot analysis and reverse transcription-quantitative PCR, respectively. Cell proliferation, invasion and migration were analyzed by MTT, colony formation, Transwell and wound healing assay. Immunofluorescence staining was adopted to estimate the content of Ki67 and western blot was applied for the evaluation of PLCD1, MMP2, MMP9, E-cadherin, N-cadherin, vimentin, Snail and ORC. The binding interaction between ORC1 and PLCD1 was analyzed using chromatin immunoprecipitation and luciferase reporter enzyme gene assays. The results indicated that PLCD1 was lowly expressed in lung adenocarcinoma cells in comparison with that in 16HBE. When PLCD1 was overexpressed in cancer cells, cell proliferation, invasion and migration were significantly inhibited. However, in the presence of both ORC1 and PLCD1 overexpression, the suppressive effects of PLCD1 overexpression alone on cell proliferation, invasion, migration and EMT were attenuated. In conclusion, ORC1 was indicated to inhibit PLCD1, thus regulating the proliferation, migration and EMT processes of lung adenocarcinoma cells, which suggested that ORC1 might be a target for the treatment of lung adenocarcinoma.

PLCD1-Induced DNA Damage Inhibits the Tumor Growth via Downregulating CDKs in Chondrosarcoma

Purpose

Typical genes for the treatment and diagnosis of high-grade chondrosarcoma are still in need. Our study aimed to explore the PLCD1 function in chondrosarcoma for further treatment.

Materials and Methods

Our study collected the information of 49 patients in our department. The PLCD1 expression in our cohort was detected and was compared with the TCGA database. PLCD1 knockdown and overexpression cell lines were established stably. Cell viability assay and colony formation assay were performed for cell proliferation. Flow cytometry analysis was performed for cell cycle and apoptosis. Western blotting was performed for PLCD1-related protein expression. Animal xenografts were established to verify the effect of PLCD1 in high-grade chondrosarcoma.

Results

Compared with the TCGA database, the relation between PLCD1 expression and the malignancy of chondrosarcoma was demonstrated. A lower PLCD1 expression was detected mainly in high-grade chondrosarcoma. PLCD1 overexpression in high-grade chondrosarcoma suppressed CDKs/cyclins and induced DNA damage causing cell cycle blocking and apoptosis. Antitumor effect of PLCD1 overexpression was verified in vivo.

Conclusion

Lower PLCD1 was expressed in high-grade chondrosarcoma. Overexpressed PLCD1-induced DNA damage caused cell cycle blocking and apoptosis in vitro and in vivo. PLCD1 could be a novel target in high-grade chondrosarcoma for further drug development.

Overarching roles of diacylglycerol signaling in cancer development and antitumor immunity

Diacylglycerol (DAG) is a lipid second messenger that is generated in response to extracellular stimuli and channels intracellular signals that affect mammalian cell proliferation, survival, and motility. DAG exerts a myriad of biological functions through protein kinase C (PKC) and other effectors, such as protein kinase D (PKD) isozymes and small GTPase-regulating proteins (such as RasGRPs). Imbalances in the fine-tuned homeostasis between DAG generation by phospholipase C (PLC) enzymes and termination by DAG kinases (DGKs), as well as dysregulation in the activity or abundance of DAG effectors, have been widely associated with tumor initiation, progression, and metastasis. DAG is also a key orchestrator of T cell function and thus plays a major role in tumor immunosurveillance. In addition, DAG pathways shape the tumor ecosystem by arbitrating the complex, dynamic interaction between cancer cells and the immune landscape, hence representing powerful modifiers of immune checkpoint and adoptive T cell-directed immunotherapy. Exploiting the wide spectrum of DAG signals from an integrated perspective could underscore meaningful advances in targeted cancer therapy.

Phospholipase C Beta 2 Protein Overexpression Is a Favorable Prognostic Indicator in Newly Diagnosed Normal Karyotype Acute Myeloid Leukemia

Phospholipase C beta 2 (PLC-β2) regulates various essential functions in cell signaling, differentiation, growth, and mobility. We investigated the clinical implications of PLC-β2 protein expression in newly diagnosed normal karyotype acute myeloid leukemia (NK-AML). The PLC-β2 expression status in bone marrow tissues obtained from 101 patients with NK-AML was determined using semiquantitative immunohistochemistry (IHC). IHC results were compared with those for known prognostic markers. Using a cutoff score for positivity of 7.0, the PLC-β2 overexpression group showed superior overall survival (OS) (72.6% vs. 26.5%; P=0.016) and low hazard ratio (HR) (0.453; P=0.019) compared with the PLC-β2 low-expression group. The PLC-β2 overexpression group showed no significant gain in event-free survival (50.6% vs. 43.0%, P=0.465) and HR (0.735; P=0.464). Among the known prognostic markers, only FLT3-ITD positivity was associated with a significantly low OS and high HR. In conclusion, PLC-β2 overexpression was associated with favorable OS in NK-AML patients. Our results suggest that PLC-β2 expression assessment using IHC allows prognosis prediction in NK-AML.

The tumor suppressor Zinc finger protein 471 suppresses breast cancer growth and metastasis through inhibiting AKT and Wnt/β-catenin signaling

Background

Zinc-finger protein 471 (ZNF471) is a member of the Krüppel-associated box domain zinc finger protein (KRAB-ZFP) family. ZNF471 is methylated in squamous cell carcinomas of tongue, stomach and esophageal. However, its role in breast carcinogenesis remains elusive. Here, we studied its expression, functions, and molecular mechanisms in breast cancer.

Methods

We examined ZNF471 expression by RT-PCR and qPCR. Methylation-specific PCR determined its promoter methylation. Its biological functions and related molecular mechanisms were assessed by CCK-8, clonogenicity, wound healing, Transwell, nude mice tumorigenicity, flow cytometry, BrdU-ELISA, immunohistochemistry and Western blot assays.

Results

ZNF471 was significantly downregulated in breast cell lines and tissues due to its promoter CpG methylation, compared with normal mammary epithelial cells and paired surgical-margin tissues. Ectopic expression of ZNF471 substantially inhibited breast tumor cell growth in vitro and in vivo, arrested cell cycle at S phase, and promoted cell apoptosis, as well as suppressed metastasis. Further knockdown of ZNF471 verified its tumor-suppressive effects. We also found that ZNF471 exerted its tumor-suppressive functions through suppressing epithelial-mesenchymal transition, tumor cell stemness and AKT and Wnt/β-catenin signaling.

Conclusions

ZNF471 functions as a tumor suppressor that was epigenetically inactivated in breast cancer. Its inhibition of AKT and Wnt/β-catenin signaling pathways is one of the mechanisms underlying its anti-cancer effects.

Noteworthy prognostic value of phospholipase C delta genes in early stage pancreatic ductal adenocarcinoma patients after pancreaticoduodenectomy and potential molecular mechanisms

The purpose of this investigation was to explore the prognostic value of phospholipase C delta (PLCD) genes in early stage pancreatic ductal adenocarcinoma (PDAC) and its potential molecular mechanisms. The prognostic value of PLCD genes in early stage PDAC was assessed using the Kaplan-Meier method and multivariate Cox proportional hazards regression model. Genome-wide correlation analysis was performed on PLCD3 to identify the highly correlated genes in the transcriptome. Then, PLCD3 and these correlated genes together underwent a bioinformatics analysis to elucidate the potential molecular biological functions of PLCD3 in PDAC. PLCD1 and PLCD3 are significantly overexpressed in PDAC. In PDAC patients, PLCD3 is overexpressed in certain groups of people with a history of alcoholism (P = .032). High expression of PLCD3 was found to be associated with lower overall survival (OS) of patients with early stage PDAC (P = .020; adjusted P = .016). A combination of PLCD3 and clinical variables was able to better predict the outcome of patients with early stage PDAC. These clinical variables are histological grade (P = .001; adjusted P = .001), targeted molecular therapy (P < .001; adjusted P < .001), radiation therapy (P = .002; adjusted P = .039), and residual resection (P = .001; adjusted P = .002). The bioinformatics analysis revealed that PLCD3 is associated with angiogenesis, intracellular signal transduction, and regulation of cell proliferation. In conclusion, PLCD3 may be a potential prognostic biomarker for early stage PDAC.