Overexpression of wip1 is associated with biologic behavior in human clear cell renal cell carcinoma

PPM1D is a potential prognostic biomarker and correlates with immune cell infiltration in hepatocellular carcinoma

Background: Protein phosphatase magnesium-dependent 1 delta (PPM1D), also referred to as wild-type p53-induced phosphatase 1 (Wip1) or protein phosphatase 2C delta (PP2Cδ), is an oncogenic nuclear serine/threonine phosphatase belonging to the PP2C family. However, the knowledge regarding PPM1D mRNA expression, tumor immunity, and the prognosis in hepatocellular carcinoma (HCC) is scanty.

Methods: We analyzed PPM1D, including its expression in both the normal and tumor tissue using the Sangerbox database and Tumor Immune Estimation Resource (TIMER). We evaluated its correlation with prognosis in different tumor types by the Kaplan-Meier plotter and Gene Expression Profiling Interactive Analysis (GEPIA). The correlations between PPM1D and the cancer immune infiltrates were determined using TIMER. The correlations between PPM1D expression and gene marker sets of the immune infiltrates were established by both the TIMER and GEPIA. Immunohistochemistry was performed to detect the expression of Wip1 protein encoded by PPM1D in HCC, and the relationship between Wip1 expression and the prognosis of HCC were analyzed.

Results: We found out that PPM1D mRNA expression was significantly higher in several human cancers, including HCC, than in the corresponding normal human tissues. The PPM1D mRNA high expression in HCC was significantly correlated with poor prognosis. The expression was associated with progression-free survival (PFS) in multiple HCC patients’ cohorts (PFS HR = 1.5, P = 0.0066). This was especially in early stage (stage 1) and AJCC_T 1 of HCC. Besides, PPM1D mRNA expression indicated a positive correlation with tumor-infiltrating Monocytes, tumor-associated macrophages (TAMs), M1 Macrophage, M2 Macrophage, dendritic cells (DCs), T-helper (Th) and Treg. Wip1 was higher in HCC than paracancerous tissue. High expression of Wip1 was associated with poor prognosis of HCC.

Conclusion: Our findings suggested that PPM1D mRNA is critical in activating tumor immunity. Besides, they implied that PPM1D could be a potential prognostic biomarker for cancer progression. Moreover, it correlated with tumor immune cell infiltration in HCC.

Radiobiology of stereotactic ablative radiotherapy (SABR): perspectives of clinical oncologists

Stereotactic ablative radiotherapy (SABR) is a novel radiation treatment method that delivers an intense dose of radiation to the treatment targets with high accuracy. The excellent local control and tolerance profile of SABR have made it become an important modality in cancer treatment. The radiobiology of SABR is a key factor in understanding and further optimizing the benefits of SABR. In this review, we have addressed several issues in the radiobiology of SABR from the perspective of clinical oncologists. The appropriateness of the linear-quadratic (LQ) model for SABR is controversial based on preclinical data, but it is a reliable tool from the perspective of clinical application because the biological effective dose (BED) calculated with it can represent the tumor control probability (TCP). Hypoxia is a common phenomenon in SABR in spite of the relatively small tumor size and has a negative effect on the efficacy of SABR. Preliminary studies indicate that a hypoxic radiosensitizer combined with SABR may be a feasible strategy, but so far there is not adequate evidence to support its application in routine practice. The vascular change of endothelial apoptosis and blood perfusion reduction in SABR may enhance the response of tumor cells to radiation. Combination of SABR with anti-angiogenesis therapy has shown promising efficacy and good tolerance in advanced cancers. SABR is more powerful in enhancing antitumor immunity and works better with immune checkpoint inhibitors (ICIs) than conventional fractionation radiotherapy. Combination of SABR with ICIs has become a practical option for cancer patients with metastases.

MicroRNA-129-2-3p directly targets Wip1 to suppress the proliferation and invasion of intrahepatic cholangiocarcinoma

Accumulated studies showed that numerous microRNAs (miRNAs) were aberrantly expressed in human intrahepatic cholangiocarcinoma (ICC) and contributed to the tumorigenic processes. However, whether miR-129-2-3p is implicated in the ICC initiation and progression is still limited. Here, the results revealed that miR-129-2-3p expression was notably decreased in ICC tissues and cell lines, and that a low miR-129-2-3p expression was obviously associated with distant metastasis and clinical stage. Exogenous miR-129-2-3p expression evidently repressed the proliferative and invasive abilities of ICC cells. Mechanistic studies indicated that Wild-type p53-induced phosphatase 1 (Wip1) was a direct target gene for miR-129-2-3p in ICC cells. Furthermore, silencing Wip1 expression mimicked the suppressive effects of miR-129-2-3p upregulation on ICC cells. Interestingly, reintroduction of Wip1 expression partially abolished the miR-129-2-3p -reduced cell proliferation and invasion in ICC. Moreover, ectopic miR-129-2-3p expression hindered the ICC tumor growth in vivo. To the best of our knowledge, it is the first time to reveal that miR-129-2-3p plays a crucial role in tumor suppression in ICC pathogenesis through directly targeting Wip1. These results will aid in elucidating the roles of miR-129-2-3p in ICC, and suggest that this miRNA may provide a potential target for the treatment of ICC

The role of PPM1D in cancer and advances in studies of its inhibitors

A greater understanding of factors causing cancer initiation, progression and evolution is of paramount importance. Among them, the serine/threonine phosphatase PPM1D, also referred to as wild-type p53-induced phosphatase 1 (Wip1) or protein phosphatase 2C delta (PP2Cδ), is emerging as an important oncoprotein due to its negative regulation on a number of crucial cancer suppressor pathways. Initially identified as a p53-regulated gene, PPM1D has been afterwards found amplified and more recently mutated in many human cancers such as breast cancer. The latest progress in this field further reveals that selective inhibition of PPM1D to delay tumor onset or reduce tumor burden represents a promising anti-cancer strategy. Here, we review the advances in the studies of the PPM1D activity and its relevance to various cancers, and recent progress in development of PPM1D inhibitors and discuss their potential application in cancer therapy. Consecutive research on PPM1D and its relationship with cancer is essential, as it ultimately contributes to the etiology and treatment of cancer.

iNOS is associated with tumorigenicity as an independent prognosticator in human intrahepatic cholangiocarcinoma

BACKGROUND

Inducible nitric oxide synthase (iNOS) has supposed to implicate in inflammation, infection, liver cirrhosis, and neoplastic diseases. This study was designed to explore the biological and clinical function of iNOS in intrahepatic cholangiocarcinoma (ICC).

METHODS

RT-PCR (Real-time quantitative PCR) and immunohistochemical staining were used to analyze the expression of iNOS in ICC and adjacent tissues. CCK8, transwell assays, flow cytometry were conducted to detect the proliferation, apoptosis, cell cycle. Western blotting was performed to detect the expression of target proteins. Multivariate analyses were conducted to analysis associates between clinicopathological values and survival.

RESULTS

We found that levels of iNOS mRNA and protein were dramatically increased in ICC samples and positively correlated with complicated bile duct stone, differentiation, pathology T, pathology M, Wip1, MMP-2, and MMP-9. iNOS expression was significantly correlated with the poor survival of ICC patients. Furthermore, iNOS was high expression in ICC cell lines (QBC-939, ICC-9810, SSP-25) compare with human normal biliary epithelium cell line (HIBEpic); both iNOS knockdown and iNOS inhibitor (1400 W) suppressed cell proliferation, invasion, and migration though nitric oxide production in ICC cells. Down-regulation of iNOS also induced G0/G1 cell cycle arrest and ICC cell apoptosis. Moreover, iNOS knockdown treatment significantly decreased Wip1, MMP-9, and MMP-2 gene expression.

CONCLUSION

Lowly expressed iNOS-inhibited proliferation yet promoted apoptosis of ICC cells. Our data show targeted inhibition of iNOS in ICC may have therapeutic value.

Somatic mosaic truncating mutations of PPM1D in blood can result from expansion of a mutant clone under selective pressure of chemotherapy

Background

PPM1D (Protein phosphatase magnesium-dependent 1δ) is known as a damage response regulator, a part of the p53 negative feedback loop. Truncating mutations of PPM1D, resulting in overexpression, are frequently found in the blood of patients with breast or ovarian cancer. To identify whether the PPM1D mutation predisposes patients to such cancers or if it results from the cancer and therapy, somatic PPM1D mutations in association with previous cancer and chemotherapy need to be explored.

Methods

We performed next-generation sequencing (NGS) analysis of blood samples from patients suspected to have hereditary cancer. We grouped the patients according to their diagnoses and history of chemotherapy. For the patients with PPM1D mutations in blood, tumor tissue specimens were examined for the PPM1D mutation using conventional sequencing.

Results

A total of 1,195 patients, including 719 patients with breast cancer and 240 with ovarian cancer, were tested, and four (~0.3%) had the truncating mutation in PPM1D. All truncating mutations were in exon 6, in mosaic form, with a mean allele fraction of 11.15%. While 395 out of the 1,195 patients had undergone chemotherapy, the four with the truncating mutation had a history of cisplatin-based chemotherapy. No corresponding mutations were identified in the tumor tissues.

Conclusions

We investigated the frequency of the somatic mosaic PPM1D mutation, in patients with breast or ovarian cancer, which is suggested to be low and related to a history of cisplatin-based chemotherapy. It may be a marker of previous exposure to selective pressure for cells with an impaired DNA damage response.

PPM1D Functions as Oncogene and is Associated with Poor Prognosis in Esophageal Squamous Cell Carcinoma

Mounting evidence has demonstrated that PPM1D participates in the development and progression of a wide variety of tumors. However, its precise roles in esophageal squamous cell carcinoma (ESCC) remain under investigation. Here, UALCAN, an interactive web-portal to perform the expression analyses of PPM1D using TCGA gene expression data, and PPM1D high expression was exhibited in primary esophageal cancer. Further investigation revealed that PPM1D expression was obviously higher in ESCC tissues than in normal tissues (P < 0.01), which was consistent with the results from real-time qPCR and Western blotting in ESCC tissues and paired normal esophageal tissues. Besides, PPM1D expression was closely correlated with TNM staging, tumor differentiation and lymph node metastasis (P < 0.01), but not related to the patients' gender and age (P > 0.05). Notably, PPM1D expression in metastatic ESCC patients was markedly higher than that in non-metastatic ESCC patients (P < 0.01), and the ESCC patients with high PPM1D expression predicted poor prognosis. Multivariate assay demonstrated that PPM1D and lymph node metastasis were considered as independent prognostic factors for the ESCC patients. These findings suggest PPM1D plays a pivotal important role in onset and progression of ESCC, and may be a new biomarker for metastasis and prognosis of the ESCC patients.

The pathophysiological significance of PPM1D and therapeutic targeting of PPM1D-mediated signaling by GSK2830371 in mantle cell lymphoma

PPM1D is a serine/threonine phosphatase that negatively regulates key DNA damage response proteins, such as p53, p38 MAPK, histone H2A.X, and ATM. We investigated the pathophysiological significance of PPM1D and its therapeutic targeting by the novel PPM1D inhibitor GSK2830371 in mantle cell lymphoma (MCL). Oncomine-based analyses indicated increased PPM1D mRNA levels in MCL cells compared with their normal counterpart cells. Higher PPM1D expression was associated with higher expression of the proliferation gene signature and poorer prognosis in patients. Eight MCL (three p53 wild-type and five mutant) cell lines were exposed to GSK2830371. GSK2830371 inhibited the cell growth, being prominent in p53 wild-type cells. GSK2830371 induced apoptosis in sensitive cells, as evidenced by induction of phosphatidylserine externalization and loss of mitochondrial membrane potential. p53 knockdown de-sensitized cell sensitivity. GSK2830371 increased the levels of total and Ser15-phosphorylated p53, and p53 targets p21 and PUMA. GSK2830371 and the MDM2 inhibitor Nutlin-3a acted synergistically in p53 wild-type cells. Interestingly, GSK2830371 sensitized MCL cells to bortezomib and doxorubicin in p53 wild-type and mutant cells; p38 signaling appeared to be involved in the GSK2830371/bortezomib lethality. PPM1D inhibition may represent a novel therapeutic strategy for MCL, which can be exploited in combination therapeutic strategies for MCL.

MicroRNA-499a-5p inhibits osteosarcoma cell proliferation and differentiation by targeting protein phosphatase 1D through protein kinase B/glycogen synthase kinase 3β signaling

A number of studies have attempted to elucidate the association between mircoRNAs (miRNAs/miRs) and cancer-associated processes. The aim of the present study was to determine how miR-499a-5p intervenes in human osteosarcoma cell proliferation and differentiation. The cancerous tissues and adjacent non-cancerous tissues of 62 patients with osteosarcoma (OS) were collected. miRNA microarray analysis revealed that 29 miRNAs were upregulated while 26 were downregulated, among which miR-499a-5p expression was the most decreased. Western blot analysis and reverse transcription-quantitative polymerase chain reaction demonstrated that the mRNA and protein expression of miR-499a-5p was lower, while that of protein phosphatase 1D (PPM1D) was higher in OS tissues compared with expression levels in normal tissues. Furthermore, miR-499a-5p expression was markedly decreased in the metastatic tumors and in those at stage III+IV compared with the non-metastatic tumors and those at stage I, respectively. In addition, following transfection of the human OS MG-63 cell line with an miR-499a-5p mimic, the expression of miR-499a-5p was elevated while the protein and mRNA expression of PPM1D was decreased. When combining these findings with the information obtained from the Targetscan predictive software, it was confirmed that PPM1D was targeted by miR-499a-5p. In MG-63 cells transfected with an miR-499a-5p mimic, PPM1D-associated downstream proteins phosphorylated protein kinase B (p-Akt) and phosphorylated glycogen synthase kinase 3β (p-GSK-3β) were significantly downregulated compared with the negative control (NC) group, while the expression of p-Akt and p-GSK-3β were significantly elevated in the tumor tissues compared with the adjacent non-tumor tissues. Simultaneously, the growth and proliferation activity of MG-63 cells were notably reduced when transfected with the miR-499a-5p mimic, compared with the NC group. Therefore, it may be concluded that miR-499a-5p suppresses OS cell proliferation and differentiation by targeting PPM1D through modulation of Akt/GSK-3β signaling.

Role of wild-type p53-induced phosphatase 1 in cancer

Wild-type p53-induced phosphatase (Wip1) is a member of the protein phosphatase type 2C family and is an established oncogene due to its dephosphorylation of several tumor suppressors and negative control of the DNA damage response system. It has been reported to dephosphorylate p53, ataxia telangiectasia mutated, checkpoint kinase 1 and p38 mitogen activated protein kinases, forming negative feedback loops to inhibit apoptosis and cell cycle arrest. Wip1 serves a major role in tumorigenesis, progression, invasion, distant metastasis and apoptosis in various types of human cancer. Therefore, it may be a potential biomarker and therapeutic target in the diagnosis and treatment of cancer. Furthermore, previous evidence has revealed a new role for Wip1 in the regulation of chemotherapy resistance. In the present review, the current knowledge on the role of Wip1 in cancer is discussed, as well as its potential as a novel target for cancer treatment and its function in chemotherapy resistance.

Wip1 is associated with tumorigenity and metastasis through MMP-2 in human intrahepatic cholangiocarcinoma

Wip1 has been shown to correlate with the metastasis/invasion of several tumors. This study was designed to investigate the clinical significance and biological function of Wip1 in intrahepatic cholangiocarcinoma (ICC). The expression of Wip1 was investigated in sixty human ICC biopsy samples by immunohistochemistry. Transient and stable knockdown of Wip1 in two human ICC cells (ICC-9810 and SSP25) were established using short hairpin RNA expression vector. Immunohistochemistry revealed that Wip1 was up-regulated in human ICC tissues (47/60, 78.3%). High levels of Wip1 in human ICC correlated with metastasis to the lymph metastasis (P=0.022). Genetic depletion of Wip1 in ICC cells resulted in significantly inhibited proliferation and invasion compared with controls. Most importantly, Wip1 down-regulation impaired tumor migration capacity of ICC cells in vivo. Subsequent investigations revealed that matrix metalloproteinase-2 (MMP-2) is an important target of Wip1. Consistently, in human ICC tissues, Wip1 level was positively correlated with MMP-2 expression. Taken together, our founding indicates that Wip1 may be a crucial regulator in the tumorigenicity and invasion of human ICC, Wip1 exerts its pro-invasion function at least in part through the MMP-2 signaling pathway, suggesting Wip1 as a potential therapeutic target for ICC.

CLASP2 is involved in the EMT and early progression after transurethral resection of the bladder tumor

Background

Cytoplasmic linker-associated protein 2 (CLASP2) belongs to a family of microtubule plus-end tracking proteins that localizes to the distal ends of microtubules and regulate microtubule dynamics. We speculated that it might be involved in the epithelial-mesenchymal transition (EMT) and progression of bladder cancer (BC).

Methods

Western blotting and RT-PCR were used to detect the changes at protein and mRNA levels in BC cell lines. Cell proliferation, clonogenic formation, wound healing and chamber invasion assay were used to investigate the abilities of cellular proliferation, migration and invasion. The data of BC patients treated with transurethral resection of the bladder tumor (TURBT) was collected and analyzed. The levels of mRNA of CLASP2 and EMT-related markers in tumor and urine samples were tested by RT-PCR.

Results

Expressions of CLASP2 varied in four BC cell lines. Manipulation of CLASP2 expression changed EMT-related markers. CLASP2 could promote proliferation, migration and invasion in BC cell lines. The combination (CLASP2 + E-cadherin mRNA in urine) could better discriminate the patients with or without 2-years progression compared with tumor grade after TURBT.

Conclusion

CLASP2 is involved in the EMT and progression of bladder urothelial cancer. Simultaneous urine-based detection of CLASP2 and E-cadherin mRNA can efficiently discriminate patients with or without 2-years progression after TURBT.

Clinical significance of Wip1 overexpression and its association with the p38MAPK/p53/p16 pathway in NSCLC

Wip1 is deregulated in numerous human malignancies. However, its roles in non-small cell lung cancer (NSCLC) remain unclear. In the current study, the expression of Wip1 was investigated in NSCLC and its clinical significance was detected. Immunohistochemical staining was used to measure the expression of (wild-type p53 induced phosphatase 1) Wip1, p38 mitogen-activated protein kinase (MAPK), p53, p16 protein in a group of 60 NSCLC and 20 normal lung tissues. In addition, western blotting was performed to detect the Wip1 protein in fresh tissues. The correlations between clinical characteristics and Wip1 expression were analyzed using SPSS, version 16.0 software. The expression of Wip1 was positive in 63.3% (38/60) of NSCLC tissues, and in none of the normal lung tissues (0/20; P<0.01). In addition, Wip1 overexpression was significantly associated with tumor length and differentiation (P=0.008 and 0.03, respectively). The expression of Wip1 was negatively correlated with that of p38MAPK, p53 and p16 (r=−0.284, −0.352 and −0.348, respectively). The results of the current study demonstrated that Wip1 was frequently overexpressed in NSCLC, which may serve an essential role in the p38MAPK/p53/p16 signaling pathway.

Morphine enhances renal cell carcinoma aggressiveness through promotes survivin level

Background: Morphine is an opioid analgesic drug often used for pain relief in cancer patients. However, there is growing evidence that morphine may modulate tumor growth, progression and metastasis. Unfortunately, the results obtained by these studies are still contradictory.

Methods: In this study, we investigated the effect of morphine in human clear cell renal cell carcinoma 786-O, RLC-310 cells and whether morphine affects on tumor growth in human clear cell renal cell carcinoma 786-O, RLC-310 cells. The cell proliferation was determined by MTT assay, cell proliferation, migration and invasion assays. Immunofluorescence staining and Q-PCR was used to determine the Survivin expression.

Results: It was shown that morphine enhances proliferation of 786-O, RLC-310 cells, whereas morphine promoted the growth and aggressive phenotype of 786-O and RLC-310 cells in vitro though Survivin-dependent signaling.

Conclusions: Our data showed that morphine promotes RCC growth and increases RCC progression via over-expression of Survivin.

MicroRNA-361-3p suppresses tumor cell proliferation and metastasis by directly targeting SH2B1 in NSCLC

Background

Lung cancer is the most common malignancies worldwide. However, the detailed molecular mechanisms underlying lung cancer progression are still not completely clear. MicroRNAs are small noncoding RNAs which occupy a crucial role of cancer metastasis. Accumulating evidence suggests that miR-361 plays important roles in human carcinogenesis. However, its precise biological role remains largely elusive, especially in lung cancer. This study examined the role of miR-361-3p in non-small cell lung cancer (NSCLC).

Methods

Real-time quantitative PCR (qRT-PCR) was used to analyze the expression of miR-361-3p in NSCLC tissue and in compared adjacent non-cancerous tissues. The effect of miR-361-3p on proliferation was evaluated by CCK8 and colony formation assays. The effect of miR-361-3p on migration and invasion was evaluated by transwell assays. Western blotting and immunohistochemical staining were applied to analyze the expression of target proteins and downstream molecule, and the luciferase reporter assay to assess the target genes of miR-361-3p in non-small cell lung cancer cells.

Results

miR-361-3p was significantly decreased in NSCLC tissue and cell lines, and its expression levels were highly correlated with lymph node metastasis (P < 0.01) and TNM stages (P < 0.05). Down-regulation of miR-361-3p promoted cell growth, proliferation, colony formation, invasion and migration in vitro, and promoted proliferation and metastasis in vivo (P < 0.01); whereas up-regulation of miR-361-3p had the contrary effects. The luciferase reporter assay showed that SH2B1 was a direct target gene of miR-361-3p. Enforced expression of miR-361-3p inhibited the expression of SH2B1 significantly and the restoration of SH2B1 expression reversed the inhibitory effects of miR-361-3p on NSCLC cell proliferation and metastasis.

Conclusions

miR-361-3p functions as a novel tumor suppressor in NSCLC and the anti-oncogenic activity may involve its inhibition of the target gene SH2B1. These findings suggest the possibility for miR-361-3p as a therapeutic target in NSCLC.

Hedgehog Signaling in the Maintenance of Cancer Stem Cells

Cancer stem cells (CSCs) represent a rare population of cells with the capacity to self-renew and give rise to heterogeneous cell lineages within a tumour. Whilst the mechanisms underlying the regulation of CSCs are poorly defined, key developmental signaling pathways required for normal stem and progenitor functions have been strongly implicated. Hedgehog (Hh) signaling is an evolutionarily-conserved pathway essential for self-renewal and cell fate determination. Aberrant Hh signaling is associated with the development and progression of various types of cancer and is implicated in multiple aspects of tumourigenesis, including the maintenance of CSCs. Here, we discuss the mounting evidence suggestive of Hh-driven CSCs in the context of haematological malignancies and solid tumours and the novel strategies that hold the potential to block many aspects of the transformation attributed to the CSC phenotype, including chemotherapeutic resistance, relapse and metastasis.