PinX1 serves as a potential prognostic indicator for clear cell renal cell carcinoma and inhibits its invasion and metastasis by suppressing MMP-2 via NF-κB-dependent transcription

MMPs-related risk model identification and SAA1 promotes clear cell renal cell carcinoma migration via ERK-AP1-MMPs axis

Matrix Metalloproteinases (MMPs) have been demonstrated to be essential in facilitating the migration and metastasis of clear cell renal cell carcinoma (ccRCC). However, the ability of the MMP family to predict clinical outcomes and guide optimal therapeutic strategies for ccRCC patients remains incompletely understood. In this investigation, we initially conducted a thorough examination of the MMP family in pan-cancer. Notably, MMPs exhibited distinctive significance in ccRCC. Following this, we undertook an extensive analysis to evaluate the clinical value of MMPs and potential mechanisms by which MMPs contribute to the progression of ccRCC. A novel stratification method and prognostic model were developed based on MMPs in order to enhance the accuracy of prognosis prediction for ccRCC patients and facilitate personalized treatment. By conducting multi-omics analysis and transcriptional regulation analysis, it was hypothesized that SAA1 plays a crucial role in promoting ccRCC migration through MMPs. Subsequently, in vitro experiments confirmed that SAA1 regulates ccRCC cell migration via the ERK-AP1-MMPs axis. In conclusion, our study has explored the potential value of the MMP family as prognostic markers for ccRCC and as guides for medication regimens. Additionally, we have identified SAA1 as a crucial factor in the migration of ccRCC.

SLUG and SNAIL as Potential Immunohistochemical Biomarkers for Renal Cancer Staging and Survival

Renal cell carcinoma (RCC) is the deadliest urological neoplasm. Up to date, no validated biomarkers are included in clinical guidelines for the screening and follow up of patients suffering from RCC. Slug (Snail2) and Snail (Snail1) belong to the Snail superfamily of zinc finger transcriptional factors that take part in the epithelial-mesenchymal transition, a process important during embryogenesis but also involved in tumor progression. We examined Slug and Snail immunohistochemical expression in patients with different stages of renal cell carcinomas with the aim to investigate their potential role as staging and prognostic factors. A total of 166 samples of malignant renal cell neoplasms were analyzed using tissue microarray and immunohistochemistry. Slug and Snail expressions were evaluated qualitatively (presence or absence), in nuclear and cytoplasmic cell compartments and compared in relation to clinical parameters. The Kaplan-Meier survival analysis showed the impact of the sarcomatoid component and Slug expression on the survival longevity. Cox regression analysis separated Slug as the only independent prognostic factor (p = 0.046). The expression of Snail was associated with higher stages of the disease (p = 0.004), especially observing nuclear Snail expression (p < 0.001). All of the tumors that had metastasized showed nuclear immunoreactivity (p < 0.001). In clear cell RCC, we showed a significant relationship between a high nuclear grade and nuclear Snail expression (p = 0.039). Our results suggest that Slug and Snail could be useful immunohistochemical markers for staging and prognosis in patients suffering from various RCCs, representing potential targets for further therapy strategies of renal cancer.

Oncogenic role of PinX1 in prostate cancer cells through androgen receptor dependent and independent mechanisms

Coregulators play an important role in prostate cancer (PCa), modulating androgen receptor (AR) action and representing a possible cause of androgen deprivation therapy failure. Pin2-interacting protein X1 (PinX1) is a nucleolar protein described as a steroid hormone receptor coregulator in breast cancer cell lines. In this work, we studied the effect of PinX1 on AR action in PCa. Our results demonstrate that PinX1 acts as an AR coactivator, increasing its transcriptional activity and target gene expression, as well as proliferation, migration and colony formation in PCa cell lines. These effects are observed in the presence and absence of AR agonist and antagonists, suggesting a possible androgen independent pathway for PinX1. We present the first oncogenic roles described for PinX1, acting as a coactivator of the AR.

Angiocrine endothelium: from physiology to cancer

The concept of cancer as a cell-autonomous disease has been challenged by the wealth of knowledge gathered in the past decades on the importance of tumor microenvironment (TM) in cancer progression and metastasis. The significance of endothelial cells (ECs) in this scenario was initially attributed to their role in vasculogenesis and angiogenesis that is critical for tumor initiation and growth. Nevertheless, the identification of endothelial-derived angiocrine factors illustrated an alternative non-angiogenic function of ECs contributing to both physiological and pathological tissue development. Gene expression profiling studies have demonstrated distinctive expression patterns in tumor-associated endothelial cells that imply a bilateral crosstalk between tumor and its endothelium. Recently, some of the molecular determinants of this reciprocal interaction have been identified which are considered as potential targets for developing novel anti-angiocrine therapeutic strategies.

PinX1 represses renal cancer angiogenesis via the mir-125a-3p/VEGF signaling pathway

BACKGROUND

PIN2/TRF1-interacting telomerase inhibitor 1 (PinX1) is a tumor suppressor in various tumors. However, the molecular mechanism underlying PinX1's role in cancer development and progression remains unclear. In this study, we aimed to uncover the new molecular mechanism and role of PinX1 in renal cell carcinoma (RCC) progression.

METHODS

We used miRNA microarray to detect the different expressed miRNAs upon PinX1 knockdown. Chromatin immunoprecipitation and Luciferase reporter assays were taken to identify the molecular mechanism of PinX1 in regulating mir-125-3p. In situ hybridization was performed to analyze the expression of mir-125a-3p in RCC using tissue microarray. The correlations between the mir-125a-3p expression level and clinicopathological features were evaluated using the χ² test. The role and molecular mechanism of PinX1 in RCC angiogenesis were investigated through a series of in vitro and in vivo experiments.

RESULTS

In this study, we discovered a new molecular mechanism of PinX1, in which PinX1 transcriptionally activated mir-125a-3p expression, thereby inhibiting the expression of vascular endothelial growth factor (VEGF), which is the target gene of mir-125a-3p. PinX1 also repressed tumor angiogenesis by increasing the mir-125a-3p expression in renal cancer. Moreover, the loss of mir-125a-3p expression was manifested in patients with RCC, and low miR-125a-3p levels correlated with poor survival of these patients.

CONCLUSIONS

PinX1 represses renal cancer angiogenesis through mir-125a-3p/VEGF signal pathway. The miR-125a-3p may be a candidate clinical prognostic marker and a novel therapeutic target in RCC.

Insufficient PINX1 expression stimulates telomerase activation by direct inhibition of EBV LMP1-NF-κB axis during nasopharyngeal carcinoma development

OBJECTIVE

Early malignant transformation of nasopharyngeal carcinoma(NPC) is associated with Epstein-Barr virus(EBV) infection and telomerase activation. The EBV latent membrane protein 1(LMP1) regulates expression of various genes by triggering NF-κB signaling pathway. PINX1 is a well-identified tumor suppressor gene by inhibiting telomerase activity and cancer cell growth. However, whether and how EBV inhibit PINX1 expression and activate telomerase in NPC is still incompletely elucidated.

METHODS

Immunohistochemistry, real-time PCR and Western blotting were utilized to explore the expression of PINX1. Chromatin immunoprecipitation(ChIP) and Dual-luciferase reporter assay were used to elucidate the regulatory mechanism between NF-κB and PINX1. TRAP-SYBR Green assay and Southern blotting were utilized to detect telomerase activity and telomere length. CCK8 and EdU tests were conducted to measure proliferation ability.

RESULTS

We demonstrated that PINX1 is down-regulated in NPC for the first time. Mechanistically, we found that LMP1 could inhibit the transcriptional activity of PINX1 by promoting the binding of p65 to three specific sites in PINX1 promoter, significantly, two(-1698/-1689, tgcaatttcc; -206/-197, cgggctttac) of which have not been reported. In addition, we also observed that LMP1 overexpression resulted in increased telomerase activity, prolonged telomere length and enhanced proliferation.

CONCLUSION

We first discovered EBV led to reduced PINX1 expression through LMP1-NF-κB-PINX1 axis, which up-regulated telomerase activity in NPC. And hence, the tumor cells acquired the ability to proliferate more exuberantly. This signaling pathway illustrates the relationship between EBV latent infection and telomerase activation, and further provides new thinking for early diagnosis and treatment in NPC.

Prognostic and Clinicopathological Value of PINX1 in Various Human Tumors: A Meta-Analysis

PINX1 (Pin2/TRF1 interacting protein X1, an intrinsic telomerase inhibitor and putative tumor suppressor gene) may represent a novel prognostic tumor biomarker. However, the results of previous studies are inconsistent and the prognostic value of PINX1 remains controversial. Therefore, we conducted a meta-analysis to determine whether PINX1 expression is associated with overall survival (OS), disease-specific survival (DSS), disease-free survival (DFS), recurrence-free survival (RFS), and clinicopathological characteristics in patients with malignant tumors. A systematic search was performed in the PubMed, Web of Science, and Embase databases in April 2018. Quality assessment was performed according to the modified Newcastle-Ottawa Scale. Pooled odds ratios (ORs) and hazard ratios (HRs) with 95.0% confidence intervals (CIs) were calculated to determine the relationship between PINX1 expression and OS, DSS, DFS/RFS, and clinicopathological characteristics. Due to the heterogeneity across the included studies, subgroup and sensitivity analyses were performed. Fixed-effects models were used when the heterogeneity was not significant and random-effects models were used when the heterogeneity was significant. Fourteen studies of 16 cohorts including 2,624 patients were enrolled. Low PINX1 expression was associated with poor OS (HR: 1.51, 95.0% CI: 1.03-2.20; P = 0.035) and DFS/RFS (HR: 1.78, 95.0% CI: 1.28-2.47; P = 0.001) but not DSS (HR: 0.80, 95.0% CI: 0.38-1.67; P = 0.548). Low PINX1 expression was also associated with lymphatic invasion (OR: 2.23, 95.0% CI: 1.35-3.70; P = 0.002) and advanced tumor-node-metastasis stage (OR: 2.43, 95.0% CI: 1.29-4.57; P = 0.006). No significant associations were observed between low PINX1 expression and sex, depth of invasion, grade of differentiation, and distant metastasis. Low PINX1 expression was associated with poor OS and DFS/RFS and lymphatic invasion and advanced tumor-node-metastasis stage, suggesting that PINX1 expression may be a useful predictor of prognosis in patients with malignant tumors.

The clinical significance of PINX1 expression in papillary thyroid carcinoma

PIN2/TERF1 interacting telomerase inhibitor 1 (PINX1) is a telomerase inhibitor located on human chromosome 8p23 and also acts as a tumor suppressor in several types of cancers, including breast, gastric, ovarian, and bladder cancer. However, the role of PINX1 expression in papillary thyroid carcinoma (PTC) has not been defined. Therefore, we investigated the role of PINX1 expression in PTC by analyzing the correlation between PINX1 expression and various clinicopathological factors. Immunohistochemistry for PINX1 was performed using a tissue microarray of samples taken from the 160 patients with PTC. We also assessed mRNA and protein expression for PINX1 via quantitative real-time polymerase chain reaction and immunohistochemical analysis. Positive staining for PINX1 was found in 16.3% of PTC cases. PINX1 expression was significantly associated with tumor size, lymph node metastasis, telomerase reverse transcriptase, promoter mutation and recurrence. PINX1 mRNA expression was more pronounced in the recurrent group than in the nonrecurrent group. In addition, results of the binary logistic regression model showed that PINX1 protein expression had a significant influence on recurrence. We concluded that PINX1 expression was associated with several clinicopathological factors and had a significant influence on recurrence in patients with PTC. Therefore, PINX1 expression could be a useful prognostic marker in PTC patients.

NDV-D90 suppresses growth of gastric cancer and cancer-related vascularization

Recent reports suggest promises on using oncolytic Newcastle disease viruses (NDV) to treat different cancers, while the effects of a NDV-D90 strain on gastric cancer remain unknown. Here we showed that NDV-D90 induced gastric cancer cell apoptosis in a dose-dependent manner in 3 gastric cancer cell lines BGC-823, SGC-7901 and MKN-28. Pronounced reduction in cell invasion was detected in NDV-D90-treated BGC-823 and SGC-7901 cells, but not in MKN-28 cells. The increases in cell apoptosis and reduction in cell growth in NDV-D90-treated gastric cancer cells seemingly resulted from augmentation of p38 signaling and suppression of ERK1/2 and Akt signaling. In vivo, orthotopic injection of NDV-D90 impaired tumor growth and induced intratumoral necrosis. Tumor cells that had been pre-treated with NDV-D90 showed defect in development of implanted tumor. Moreover, NDV-D90 appeared to reduce gastric tumor vascularization, possibly through suppression of vascular endothelial growth factor A and Matrix Metallopeptidase 2. Together, our data suggest that NDV-D90 may have potential anti-cancer effects on gastric cancer.

Dicer suppresses MMP-2-mediated invasion and VEGFA-induced angiogenesis and serves as a promising prognostic biomarker in human clear cell renal cell carcinoma

Dicer, a key component of the microRNA processing machinery, has been reported to exert discrepant prognostic values and biological roles in different types of cancers. Here, we investigated the function and prognostic value of Dicer in clear cell renal cell carcinoma (ccRCC). Using the retrospective ccRCC patients’ cohorts with tissue microarray (TMA), we demonstrated that Dicer expression was significantly down-regulated in ccRCC compared with renal non-tumor tissues, and negatively associated with pN status (P = 0.005), pM status (P = 0.009) and TNM stage (P =0.013). Multivariate Cox proportional hazards regression analyses showed that positive Dicer expression was an independent favorable factor for prognosis of ccRCC patients (hazard ratio (HR) = 0.709, P = 0.025 for 5-year overall survival; HR = 0.655, P = 0.008 for disease specific survival). Moreover, we found that Dicer decreased the abilities of cell migration, invasion and angiogenesis through suppressing MMP-2 and VEGFA expression. Tumor metastasis model in vivo showed much more metastatic nodules of lung in the Dicer knockdown group than the control group via increased MMP-2 expression. Our findings imply that Dicer inhibits ccRCC metastasis and may serve as promising prognostic biomarkers for ccRCC patients.

PTBP1 knockdown in renal cell carcinoma inhibits cell migration, invasion and angiogenesis in vitro and metastasis in vivo via the hypoxia inducible factor-1α pathway

Polypyrimidine tract-binding protein 1 (PTBP1), a heterogeneous nuclear ribonucleoprotein, is a multi-functional RNA-binding protein. PTBP1 participates in a number of biological processes, including maintaining cell structure and motility, immunity, protein metabolism and the cell cycle. The present study aimed to investigate the association between PTBP1 expression and the prognosis and clinicopathological characteristics of patients with renal cell cancer (RCC). The potential mechanism of action of PTBP1 in the metastasis of RCC was also investigated. The results demonstrated that PTBP1 was overexpressed in RCC tissues compared with normal renal tissues. Furthermore, PTBP1 expression was negatively associated with patient prognosis and positively associated with tumor size, pathological tumor (pT) and pathological metastasis (pM) status and tumor lymph node metastasis (TNM) stage. PTBP1 knockdown in vitro inhibited RCC cell migration, invasion, proliferation and angiogenesis, and it was demonstrated that PTBP1 affected RCC cells primarily via the hypoxia inducible factor-1α pathway. Furthermore, PTBP1 knockdown decreased RCC lung metastasis in vivo. The present study demonstrated that PTBP1 knockdown suppresses tumor progression and metastasis, indicating that PTBP1 is an important prognostic factor in RCC and that it may be developed as a novel method of treating patients with RCC.

PinX1: structure, regulation and its functions in cancer

PIN2/TRF1-interacting telomerase inhibitor 1 (PinX1) is a novel cloned gene located at human chromosome 8p23, playing a vital role in maintaining telomeres length and chromosome stability. It has been demonstrated to be involved in tumor genesis and progression in most malignancies. However, some researches showed opposing molecular status of PinX1 gene and its expression patterns in several other types of tumors. The pathogenic mechanism of PinX1 expression in human malignancy is not yet clear. Moreover, emerging evidence suggest that PinX1 (especially its TID domain) might be a potential new target cancer treatment. Therefore, PinX1 may be a new potential diagnostic biomarker and therapeutic target for human cancers, and may play different roles in different human cancers. The functions and the mechanisms of PinX1 in various human cancers remain unclear, suggesting the necessity of further extensive works of its role in tumor genesis and progression.

PINX1 and TERT Are Required for TNF-α-Induced Airway Smooth Muscle Chemokine Gene Expression

Airway smooth muscle (ASM) cells contribute to asthmatic lung pathology with chemokine hypersecretion and increased ASM cell mass. With little recent progress in the development of asthma therapies, a greater understanding of lung inflammation mechanisms has become a priority. Chemokine gene expression in ASM cells is dependent upon NF-κB transcription factor activity. The telomerase/shelterin complex maintains chromosomal telomere ends during cell division. Telomerase is a possible cofactor for NF-κB activity, but its role in NF-κB activity in airway tissue inflammation is not known. In this study, we sought to address two key questions: whether telomerase is involved in inflammation in ASM cells, and whether components of the shelterin complex are also required for an inflammatory response in ASM cells. Telomerase inhibitors and telomerase small interfering RNA (siRNA) reduced TNF-α-induced chemokine expression in ASM cells. Telomerase siRNA and inhibitors reduced NF-κB activity. An siRNA screen of shelterin components identified a requirement for PIN2/TERF1 interacting-telomerase inhibitor 1 (PINX1) in chemokine gene expression. High-level PINX1 overexpression reduced NF-κB reporter activity, but low-level expression amplified NF-κB activity. Coimmunoprecipitation studies showed association of PINX1 and p65. Overexpression of the N terminus (2-252 aa) of PINX1, but not the C-terminal telomerase-inhibitor domain (253-328 aa), amplified TNF-α-induced NF-κB activity. GST pull-downs demonstrated that the N terminus of PINX1 bound more p65 than the C-terminal telomerase-inhibitor domain; these observations were confirmed in whole cells with N-terminal and C-terminal PINX1 immunoprecipitation. We conclude that telomerase and PINX1 are required for chemokine expression in ASM cells and represent significant new targets for future anti-inflammatory therapies for lung diseases, such as asthma.

RUNX3 regulates renal cell carcinoma metastasis via targeting miR-6780a-5p/E-cadherin/EMT signaling axis

Runt-related transcription factor 3 (RUNX3) is a tumor suppressor in many human solid tumors. In this study, renal cell carcinoma (RCC) microarray analysis showed that the level of RUNX3 expression was lower in RCC tissue than in adjacent normal renal tissues, and was correlated with depth of invasion (pT stage) (P<0.001) and Tumor Node Metastasis (TNM) stage (P<0.001). RUNX3 expression was negatively correlated with poor 5-year overall and disease-free patient survival. RUNX3 suppressed RCC metastasis and invasion and increased levels of E-cadherin, an important marker of epithelial-mesenchymal transition, in vitro and in vivo. RUNX3 also inhibited microRNA-6780a-5p, which directly targeted the E-cadherin 3'untranslated region and decreased its expression. We confirmed that miR-6780a-5p mimics abrogated RUNX3-mediated E-cadherin upregulation and RCC metastasis/invasion inhibition. Thus, RUNX3 targeted the miR-6780a-5p/E-cadherin/EMT signaling axis to suppress renal carcinoma cell migration and invasion. This pathway illustrates a new RUNX3 function and provides potential targets for the treatment of RUNX3 mutant and loss-of-function RCC tumors. RUNX3 may also act as an effective prognostic indicator in RCC.

Genetic profile and biological implication of PIN2/TRF1-interacting telomerase inhibitor 1 (PinX1) in human cancers: an analysis using The Cancer Genome Atlas

Pin2/TRF1-interacting telomere inhibitor 1 (PinX1) was originally identified as a telomerase inhibitor, involved in maintaining telomerase activity, telomere length, and chromosomal stability. However, research has shown that PinX1 can have opposing molecular status in its expression patterns in several other tumor types. We thus investigated the genetic profile and biological implication of PinX1 in several human cancers using the cBioportal database. Our results showed that PinX1 deletion accounted for the most alterations, with the frequency of its deletion regularly occurring in pathological types of carcinosarcoma and adenocarcinoma. We found few instances of PinX1 gene mutations and 3D structural analysis demonstrated that these mutation sites were always located within telomerase inhibitor domains. Furthermore, our analysis of several human cancers from the cBioportal database revealed more frequent PinX1 homozygous depletion and PinX1 heterozygous deficiency, but both more infrequent PinX1 gain and rare instances of PinX1 amplification. The status of PinX1 genetic alterations was correlated with prognosis and may be tumor-type specific. As such, its biological function in tumorigenesis and later prognosis is complicated and may involve co-worked with NEIL2, R3HCC1, POLR3D, GTF2E2, and INTS10. In addition, we observed that PinX1 interacts with TERT, DKC1, PTGES3, and HSP90AA1. PinX1 mRNA expression was decreased in most selected cancer tissues, which could promote tumor growth and enhance tumorigenicity. Collectively, our data reveal PinX1 expression patterns and potential mechanisms in various human cancers. Further work will be needed to comprehensively examine its role in tumor genesis and progression.

RUNX3 regulates hepatocellular carcinoma cell metastasis via targeting miR-186/E-cadherin/EMT pathway

Runt-related transcription factor 3 (RUNX3) has been reported as a tumor suppressor in some kinds of cancers. In the present study, hepatocellular carcinoma (HCC) microarray analysis showed that RUNX3 expression was significantly lower in HCC tissues compared with that in adjacent non-tumor tissues, and was negatively associated with metastasis and TNM stage. RUNX3 was an independently prognostic factor for 5-year overall and disease-free patient survival. Mechanically, RUNX3 repressed metastasis and invasion of HCC, and increased E-cadherin expression. RUNX3 also repressed microRNA-186 to increase E-cadherin expression. We demonstrated that miR-186 mimics attenuated RUNX3-induced increase of E-cadherin and inhibition of metastasis and invasion. In conclusion, RUNX3 suppressed HCC cell migration and invasion by targeting the miR-186/E-cadherin/EMT pathway. RUNX3 may be recommended as an effective prognostic indicator and therapeutic target for patients with HCC.

Low expression of PinX1 is associated with malignant behavior in basal-like breast cancer

Human Pinx1 protein, associated with shelterin proteins, is widely revealed as a haploinsufficient tumor suppressor. Growing evidence has manifested the deregulation of PinX1 in distinct cancers. Nonetheless, the loss status of PinX1 and its diagnostic, prognostic and clinicopathological significance in Basal-like breast cancer are still unclear. In the present study, the PinX1 expression levels of breast cancer tissues were investigated by qRT-PCR and immunoblotting assays. Then immunohistochemistry (IHC) was performed to detect PinX1 expression on a tissue microarray. The optimal threshold for PinX1 positivity was determined by receiver operating characteristic (ROC) curve analysis. To clarify the probable role of PinX1 in BLBC, the PinX1 knockout and stably over-expressed MDA-MB-231 cell lines were constructed by the CRISPR-Cas9 system and gene transfection. The association of PinX1 expression with cell proliferation, migration and apoptosis of MDA-MB-231 cells were observed by CCK-8 assay, wound healing assay, Transwell assay, flow cytometric analysis and immunoblotting of the cleaved caspase-3 protein level. Our results showed that both PinX1 mRNA and protein expression were downregulated in breast cancer tissues (P<0.05). In IHC analysis, the optimal cut-off parameter for PinX1 positive expression was 62.5% (the AUC was 0.749, P<0.01). PinX1 positivity was 76.9% (10/14) in luminal subtypes, 50% (5/10) in Her2-enriched breast cancer and 27.3% (9/33) in basal-like subtypes. Besides, in 59 invasive ductal breast carcinomas, PinX1 expression was inversely related to histology grade (P<0.05) while it was positively associated with PR status (P<0.05) and ER status (P<0.05). These results indicated that low expression of PinX1 correlated with aggressive clinicopathological significance of breast cancer, especially in the basal-like subtype. Besides, we identified that overexpression of PinX1 inhibited the proliferation rates and migration ability and increased the apoptosis rates of BLBC. Our findings demonstrated that low expression of PinX1 was associated with malignant behaviors in basal-like subtype of breast cancer. PinX1 is likely a feasible biomarker and molecular target of BLBC.

The depletion of PinX1 involved in the tumorigenesis of non-small cell lung cancer promotes cell proliferation via p15/cyclin D1 pathway

Background

The telomerase/telomere interacting protein PinX1 has been suggested as a tumor suppressor. However, the clinical and biological significance of PinX1 in human non-small cell lung cancer (NSCLC) is unclear.

Methods

PinX1 gene/expression pattern and its association with NSCLC patient survival were analyzed in cBioportal Web resource and two cohorts of NSCLC samples. A series of in vivo and in vitro assays were performed to elucidate the function of PinX1 on NSCLC cells proliferation and underlying mechanisms.

Results

More frequency of gene PinX1 homozygous deletion and heterozygote deficiency was first retrieved from cBioportal Web resource. Low expression of PinX1 correlated with smoking condition, histological type, T stage, N stage, M stage and TNM stage, and was an independent predictor for overall survival in a learning cohort (n = 93) and a validation cohort (n = 51) of NSCLC patients. Furthermore, knockdown of PinX1 dramatically accelerated NSCLC cell proliferation and G1/S transition, whereas ectopic overexpression of PinX1 substantially inhibited cell viability and cell cycle transition in vitro and in vivo. p15/cyclin D1 pathway and BMP5 might contribute to PinX1-associated cell proliferation and cell cycle transition.

Conclusion

The cost-effective expression of PinX1 could constitute a novel molecular predictor/marker for NSCLC management.

Electronic supplementary material

The online version of this article (doi:10.1186/s12943-017-0637-4) contains supplementary material, which is available to authorized users.

Biological Features of a Renal Cell Carcinoma Cell Line Derived from Spinal Metastasis

The establishment of a metastatic renal cell carcinoma (mRCC) cell line can facilitate the search for molecular mechanisms involved in RCC metastasis. A novel human mRCC cell line, designated RCC96, was established from an mRCC of the spine from a 65-year-old Chinese man. Morphology, cell cycle phase, chromosome number, cell capability of migration, tumorigenicity in nude mice, and cytogenetic features of RCC96 were investigated. Cell growth curve was detected and the cell number doubling time was 52 h. Karyotype analysis showed that these cells were polyploidy. Transmission electron microscope showed that cells were with large atypical nuclei, well-developed rough endoplasmic reticulum, rich Golgi complex, and mitochondria, as well as visible microacinar in the cytoplasm. PCR and immunofluorescence staining demonstrated that the expression of some genes such as KISS-1, MMP2, and VEGF in RCC96 was not entirely consistent with that in other RCC cell lines, indicating the differences between primary and metastatic RCC cell lines. The RCC96 cell line may serve as a useful tool for studying the molecular pathogenesis and testing new therapeutic reagents for mRCC.

Senescence marker protein 30 (SMP30) serves as a potential prognostic indicator in hepatocellular carcinoma

Senescence marker protein 30 (SMP30) has been identified as a tumor-related molecule of hepatocellular carcinoma (HCC). Its clinical significance and underlying mechanisms in HCC tissues, however, remain largely unexplored. We have demonstrated a preferentially expressed SMP30 in normal liver using a tissue microarray. By employing real-time quantitative PCR, two tissue microarrays and Oncomine database analysis, we have also shown that the SMP30 in HCC tissues has significantly reduced when compared with that in paired adjacent non-tumor tissues (P = 0.0037). The reduced expression of SMP30 is very noticeably related to larger tumor size (P = 0.012), enhanced TNM (P = 0.009) and worse survival (P < 0.0001) in HCC patients. The analyses using Cox regression have indicated that the decreased SMP30 expression is an independent risk to the reduced overall survival rate of HCC patients (P = 0.001), and the down-regulation of SMP30 in HCC might be mediated by DNA methylation. Moreover, genes co-expressed with SMP30 may affect the prognosis through apoptotic process, biological adhesion and blood coagulation by PANTHER analyses. Our studies have indicated that the SMP30 may serve as a candidate of HCC clinical prognostic marker and a potential therapeutic target.

ING4 suppresses tumor angiogenesis and functions as a prognostic marker in human colorectal cancer

ING4, a potential tumor suppressor, is implicated in cell cycle arrest, apoptosis, cell migration and angiogenesis. Here, we investigated the clinical value of ING4 and its impact on angiogenesis in colorectal cancer (CRC). In this study, we found that ING4 expression was significantly reduced in CRC tissues versus paired normal colon tissues. Moreover, low ING4 expression was significantly associated with increased lymph node metastasis, advanced TNM stage and poor overall survival. Multivariate Cox regression analysis showed that ING4 expression was an independent favourable prognostic factor for CRC (hazard ratio = 0.45, P = 0.001). In addition, we found that ING4 strongly inhibited CRC angiogenesis by suppressing Sp1 expression and transcriptional activity through ubiquitin degradation and down-regulating the expressions of Sp1 downstream pro-angiogenic genes, MMP-2 and COX-2. Moreover, ING4 might inhibit phosphorylation activity of cyclin/CDK2 complexes to trigger Sp1 degradation by inducing p21 expression in despite of p53 status. Our findings imply that reduced ING4 expression in CRC resulted in increased angiogenesis and contributed to CRC metastasis and poor prognosis. Restoration of ING4 may be a novel strategy for the treatment of metastatic CRC.

Ginkgo biloba extract mitigates liver fibrosis and apoptosis by regulating p38 MAPK, NF-κB/IκBα, and Bcl-2/Bax signaling

Background

Liver fibrosis is the consequence of diverse liver injuries and can eventually develop into liver cirrhosis. Ginkgo biloba extract (GBE) is an extract from dried ginkgo leaves that has many pharmacological effects because of its various ingredients and has been shown to be hepatoprotective.

Purpose and methods

Aimed to investigate the underlying protective mechanisms of GBE on carbon tetrachloride (CCl₄)-induced liver fibrosis in rats. Male Sprague Dawley rats were randomly divided into four groups: control group (C), model group (M), low-dose group (L), and high-dose group (H). Liver fibrosis was induced by CCl₄ groups M, L, and H: group C was administered saline. In addition, GBE at different doses was used to treat groups L and H.

Results

The results of hematoxylin and eosin staining, Masson’s trichrome staining, a liver function index, and a liver fibrosis index showed that GBE application noticeably mitigated fibrosis and improved the function of the liver. The western blotting and immunohistochemistry analyses indicated that GBE reduced liver fibrosis not only by inhibiting p38 MAPK and NF-κBp65 via inhibition of IκBα degradation but also by inhibiting hepatocyte apoptosis via downregulation of Bax, upregulation of Bcl-2, and subsequent inhibition of caspase-3 activation. Inflammation-associated factors and hepatic stellate cell (HSC)-activation markers further demonstrated that GBE could effectively inhibit HSC activation and inflammation as a result of its regulation of p38 MAPK and nuclear factor-kappa B/IκBα signaling.

Conclusion

Our findings indicated a novel role for GBE in the treatment of liver fibrosis. The potential mechanisms may be associated with the following signaling pathways: 1) the p38 MAPK and nuclear factor-kappa B/IκBα signaling pathways (inhibiting inflammation and HSCs activation) and 2) the Bcl-2/Bax signaling pathway (inhibiting the apoptosis of hepatocytes).

P16-specific DNA methylation by engineered zinc finger methyltransferase inactivates gene transcription and promotes cancer metastasis

Background

P16 DNA methylation is well known to be the most frequent event in cancer development. It has been reported that genetic inactivation of P16 drives cancer growth and metastasis, however, whether P16 DNA methylation is truly a driver in cancer metastasis remains unknown.

Results

A P16-specific DNA methyltransferase (P16-dnmt) expression vector is designed using a P16 promoter-specific engineered zinc finger protein fused with the catalytic domain of dnmt3a. P16-dnmt transfection significantly decreases P16 promoter activity, induces complete methylation of P16 CpG islands, and inactivates P16 transcription in the HEK293T cell line. The P16-Dnmt coding fragment is integrated into an expression controllable vector and used to induce P16-specific DNA methylation in GES-1 and BGC823 cell lines. Transwell assays show enhanced migration and invasion of these cancer cells following P16-specific DNA methylation. Such effects are not observed in the P16 mutant A549 cell line. These results are confirmed using an experimental mouse pneumonic metastasis model. Moreover, enforced overexpression of P16 in these cells reverses the migration phenotype. Increased levels of RB phosphorylation and NFκB subunit P65 expression are also seen following P16-specific methylation and might further contribute to cancer metastasis.

Conclusion

P16 methylation could directly inactivate gene transcription and drive cancer metastasis.

Electronic supplementary material

The online version of this article (doi:10.1186/s13059-015-0819-6) contains supplementary material, which is available to authorized users.