SSX2IP promotes metastasis and chemotherapeutic resistance of hepatocellular carcinoma

miR-512-3p as a Potential Biomarker of Poor Outcome in Pediatric Medulloblastoma

The tumorigenesis of medulloblastoma (MB), the most frequent malignant brain tumor in children, is not completely known. MicroRNA (miRNA) expression profiles have been associated with human cancers; however, the role played by miRNAs in pediatric MB has been poorly explored. Global miRNA expression in MB and non-neoplastic cerebellum samples was evaluated by microarray assay. Nine miRNAs (miR-31-5p, -329, -383, -433, -485-3p, -485-5p, -491, -512-3p, and 539-5p) in 51 pediatric MB and 7 pediatric non-neoplastic cerebellum samples were chosen for validation by qRT-PCR. The validated miRNAs were less expressed in the MB samples than in the non-neoplastic controls. In our cohort of patients, higher miR-512-3p expression was associated with incomplete degree of resection, classification as high risk, classification as group 4, and poor overall survival. In silico analysis in an independent cohort of MB patients identified that some of the miR-512-3p target genes were also correlated with prognostic features. Our results have shown that miR-512-3p could be associated with poor clinical outcomes in pediatric MB, suggesting that miR-512-3p is a potential biomarker of prognosis.

SSX2IP promotes cell proliferation and migration in breast cancer by regulating FANCI

Synovial sarcoma X breakpoint 2 interacting protein (SSX2IP) is expressed in various normal tissues and participates in the progression of human cancers. Nevertheless, the specific functions and underlying molecular mechanisms of SSX2IP in cancer, particularly in breast cancer, remain poorly understood. In this study, we aimed to explore the functional role of SSX2IP in breast cancer. Immunohistochemical staining, quantitative real-time PCR, and western blotting blot analysis were used to assess genes expression levels. By manipulating SSX2IP expression levels and conducting functional assays including Celigo cell counting assay or CCKCCK-8-8 assay, flow cytometry, wound healing assay, and Transwell assay, we explored the impact of SSX2IP on the malignant phenotype of breast cancer cells. Additionally, the in vivo tumor-suppressive ability of SSX2IP was investigated by tumor xenograft experiment. Our results revealed an upregulation of SSX2IP in the breast cancer. Functional assays demonstrated that SSX2IP knockdown inhibited cell proliferation and migration, induced apoptosis in vitro, as well as suppressed the tumor growth in vivo. Conversely, SSX2IP overexpression contributed to the malignant phenotype of breast cancer cells. Co-expression analysis showed that FA Complementation Group I (FANCI) was co-expressed with SSX2IP. Additionally, SSX2IP positively regulated FANCI expression and its interaction was verified by Co-IP.Co-IP. Furthermore, FANCI overexpression partially reversed the effects of SSX2IP knockdown on cell proliferation and metastasis. In summary, our findings revealed that SSX2IP contributes to the progression of breast cancer by regulating FANCI, hinting at its potential as a novel biomarker and therapeutic target for the treatment of breast cancer.

Discovery and Validation of Survival-Specific Genes in Papillary Renal Cell Carcinoma Using a Customized Next-Generation Sequencing Gene Panel

PURPOSE

Papillary renal cell carcinoma (PRCC), the second most common kidney cancer, is morphologically, genetically, and molecularly heterogeneous with diverse clinical manifestations. Genetic variations of PRCC and their association with survival are not yet well-understood. This study aimed to identify and validate survival-specific genes in PRCC and explore their clinical utility.

MATERIALS AND METHODS

Using machine learning, 293 patients from the Cancer Genome Atlas-Kidney Renal Papillary Cell Carcinoma (TCGA-KIRP) database were analyzed to derive genes associated with survival. To validate these genes, DNAs were extracted from the tissues of 60 Korean PRCC patients. Next generation sequencing was conducted using a customized PRCC gene panel of 202 genes, including 171 survival-specific genes. Kaplan-Meier and Log-rank tests were used for survival analysis. Fisher's exact test was performed to assess the clinical utility of variant genes.

RESULTS

A total of 40 survival-specific genes were identified in the TCGA-KIRP database through machine learning and statistical analysis. Of them, 10 (BAP1, BRAF, CFDP1, EGFR, ITM2B, JAK1, NODAL, PCSK2, SPATA13, and SYT5) were validated in the Korean-KIRP database. Among these survival gene signatures, three genes (BAP1, PCSK2, and SPATA13) showed survival specificity in both overall survival (OS) (p = 0.00004, p = 1.38 × 10-7, and p = 0.026, respectively) and disease-free survival (DFS) (p = 0.00002, p = 1.21 × 10-7, and p = 0.036, respectively). Notably, the PCSK2 mutation demonstrated survival specificity uniquely in both the TCGA-KIRP (OS: p = 0.010 and DFS: p = 0.301) and Korean-KIRP (OS: p = 1.38 × 10-7 and DFS: p = 1.21 × 10-7) databases.

CONCLUSIONS

We discovered and verified genes specific for the survival of PRCC patients in the TCGA-KIRP and Korean-KIRP databases. The survival gene signature, including PCSK2 commonly obtained from the 40 gene signature of TCGA and the 10 gene signature of the Korean database, is expected to provide insight into predicting the survival of PRCC patients and developing new treatment.

Centrosome amplification-related signature correlated with immune microenvironment and treatment response predicts prognosis and improves diagnosis of hepatocellular carcinoma by integrating machine learning and single-cell analyses

BACKGROUND

Centrosome amplification is a well-recognized oncogenic driver of tumor initiation and progression across a variety of malignancies and has been linked with tumor aggressiveness, metastasis, and adverse prognosis. Nevertheless, the significance of centrosome amplification in HCC is not well understood.

METHODS

The TCGA dataset was downloaded for centrosome amplification-related signature construction using the LASSO-penalized Cox regression algorithm, while the ICGC dataset was obtained for signature validation. Single-cell RNA sequencing from GSE149614 was analyzed to profile gene expression and the liver tumor niche.

RESULTS

A total of 134 centrosome amplification-related prognostic genes in HCC were detected and 6 key prognostic genes (SSX2IP, SPAG4, SAC3D1, NPM1, CSNK1D, and CEP55) among them were screened out to construct a signature with both high sensitivity and specificity in diagnosis and prognosis of HCC patients. The signature, as an independent factor, was associated with frequent recurrences, high mortality rates, advanced clinicopathologic features, and high vascular invasions. Moreover, the signature was intimately associated with cell cycle-related pathways and TP53 mutation profile, suggesting its underlying role in accelerating cell cycle progression and leading to liver cancer development. Meanwhile, the signature was also closely correlated with immunosuppressive cell infiltration and immune checkpoint expression, making it a vital immunosuppressive factor in the tumor microenvironment. Upon single-cell RNA sequencing, SSX2IP and SAC3D1 were found to be specially expressed in liver cancer stem-like cells, where they promoted cell cycle progression and hypoxia.

CONCLUSIONS

This study provided a direct molecular link of centrosome amplification with clinical characteristics, tumor microenvironment, and clinical drug-response, highlighting the critical role of centrosome amplification in liver cancer development and therapy resistance, thereby providing valuable insights into prognostic prediction and therapeutic response of HCC.

Network analysis of hepatocellular carcinoma liquid biopsies augmented by single-cell sequencing data

Liquid biopsy, the analysis of body fluids, represents a promising approach for disease diagnosis and prognosis with minimal intervention. Sequencing cell-free RNA derived from liquid biopsies has been very promising for the diagnosis of several diseases. Cancer research, in particular, has emerged as a prominent candidate since early diagnosis has been shown to be a critical determinant of disease prognosis. Although high-throughput analysis of liquid biopsies has uncovered many differentially expressed genes in the context of cancer, the functional connection between these genes is not investigated in depth. An important approach to remedy this issue is the construction of gene networks which describes the correlation patterns between different genes, thereby allowing to infer their functional organization. In this study, we aimed at characterizing extracellular transcriptome gene networks of hepatocellular carcinoma patients compared to healthy controls. Our analysis revealed a number of genes previously associated with hepatocellular carcinoma and uncovered their association network in the blood. Our study thus demonstrates the feasibility of performing gene co-expression network analysis from cell-free RNA data and its utility in studying hepatocellular carcinoma. Furthermore, we augmented cell-free RNA network analysis with single-cell RNA sequencing data which enables the contextualization of the identified network modules with cell-type specific transcriptomes from the liver.

Correlation between Immunohistochemical Markers in Hepatocellular Carcinoma Cells and In Vitro High-Throughput Drug Sensitivity Screening

AIM

This study analyzed the correlation between immunohistochemical markers in hepatocellular carcinoma cells and the results of in vitro high-throughput drug sensitivity screening, to provide a reference for individualized drug treatment in patients with liver cancer.

METHODS

Seventy-four patients with hepatocellular carcinoma were included in this study from December 2019 to June 2021, and their liver cancer cells were used for in vitro high-throughput drug sensitivity screening. According to the screening results, the patients were divided into relatively sensitive and insensitive groups, and the correlations between sensitivity and immunohistochemistry results were analyzed statistically.

RESULTS

Alpha-fetoprotein (AFP)-positive liver cancer cells were significantly more sensitive to gemcitabine than AFP-negative cells (χ ² = 6.102, P=0.014). AFP was also positively correlated with sensitivity of liver cancer cells to three combined regimens containing oxaliplatin (L-OHP) and epirubicin (EPI) : L-OHP + EPI + irinotecan + 5-fluorouracil (5-FU), L-OHP + irinotecan + EPI, and L-OHP + EPI (χ ² = 8.168, P=0.004, χ ² = 5.705, P=0.017, and χ ² = 8.275, P=0.004, respectively).

CONCLUSION

Gemcitabine and L-OHP + EPI + irinotecan + 5-FU, L-OHP + EPI, and L-OHP + irinotecan + EPI were more effective against AFP-positive compared with AFP-negative liver cancer cells according to in vitro high-throughput drug sensitivity screening. These results may guide the selection of personalized drug treatments for patients with advanced liver cancer in the future but still need further clinical studies to confirm.

A signature of saliva-derived exosomal small RNAs as predicting biomarker for esophageal carcinoma: a multicenter prospective study

BACKGROUND

The tRNA-derived small RNAs (tsRNAs) are produced in a nuclease-dependent manner in responses to variety of stresses that are common in cancers. We focus on a cancer-enriched tsRNA signature to develop a salivary exosome-based non-invasive biomarker for human esophageal squamous cell carcinoma (ESCC).

METHODS

Cancer-enriched small RNAs were identified by RNA sequencing of salivary exosomes obtained from ESCC patients (n = 3) and healthy controls (n = 3) in a pilot study and further validated in discovery cohort (n = 66). A multicenter prospective observational study was conducted in two ESCC high-incidence regions (n = 320 and 200, respectively) using the newly developed biomarker signature.

RESULTS

The tsRNA (tRNA-GlyGCC-5) and a previously undocumented small RNA were specifically enriched in salivary exosomes of ESCC patients, ESCC tissues and ESCC cells. The bi-signature composed of these small RNAs was able to discriminate ESCC patients from the controls with high sensitivity (90.50%) and specificity (94.20%). Based on the bi-signature Risk Score for Prognosis (RSP), patients with high-RSP have both shorter overall survival (OS) (HR 4.95, 95%CI 2.90-8.46) and progression-free survival (PFS) (HR 3.69, 95%CI 2.24-6.10) than those with low-RSP. In addition, adjuvant therapy improved OS (HR 0.47, 95%CI 0.29-0.77) and PFS (HR 0.36, 95%CI 0.21-0.62) only for patients with high but not low RSP. These findings are consistent in both training and validation cohort.

CONCLUSIONS

The tsRNA-based signature not only has the potential for diagnosis and prognosis but also may serve as a pre-operative biomarker to select patients who would benefit from adjuvant therapy.

TRIAL REGISTRATION

A prospective study of diagnosis biomarkers of esophageal squamous cell carcinoma, ChiCTR2000031507 . Registered 3 April 2016 - Retrospectively registered.

Reduced RBPMS Levels Promote Cell Proliferation and Decrease Cisplatin Sensitivity in Ovarian Cancer Cells

Worldwide, the number of cancer-related deaths continues to increase due to the ability of cancer cells to become chemotherapy-resistant and metastasize. For women with ovarian cancer, a staggering 70% will become resistant to the front-line therapy, cisplatin. Although many mechanisms of cisplatin resistance have been proposed, the key mechanisms of such resistance remain elusive. The RNA binding protein with multiple splicing (RBPMS) binds to nascent RNA transcripts and regulates splicing, transport, localization, and stability. Evidence indicates that RBPMS also binds to protein members of the AP-1 transcription factor complex repressing its activity. Until now, little has been known about the biological function of RBPMS in ovarian cancer. Accordingly, we interrogated available Internet databases and found that ovarian cancer patients with high RBPMS levels live longer compared to patients with low RBPMS levels. Similarly, immunohistochemical (IHC) analysis in a tissue array of ovarian cancer patient samples showed that serous ovarian cancer tissues showed weaker RBPMS staining when compared with normal ovarian tissues. We generated clustered regularly interspaced short palindromic repeats (CRISPR)-mediated RBPMS knockout vectors that were stably transfected in the high-grade serous ovarian cancer cell line, OVCAR3. The knockout of RBPMS in these cells was confirmed via bioinformatics analysis, real-time PCR, and Western blot analysis. We found that the RBPMS knockout clones grew faster and had increased invasiveness than the control CRISPR clones. RBPMS knockout also reduced the sensitivity of the OVCAR3 cells to cisplatin treatment. Moreover, β-galactosidase (β-Gal) measurements showed that RBPMS knockdown induced senescence in ovarian cancer cells. We performed RNAseq in the RBPMS knockout clones and identified several downstream-RBPMS transcripts, including non-coding RNAs (ncRNAs) and protein-coding genes associated with alteration of the tumor microenvironment as well as those with oncogenic or tumor suppressor capabilities. Moreover, proteomic studies confirmed that RBPMS regulates the expression of proteins involved in cell detoxification, RNA processing, and cytoskeleton network and cell integrity. Interrogation of the Kaplan-Meier (KM) plotter database identified multiple downstream-RBPMS effectors that could be used as prognostic and response-to-therapy biomarkers in ovarian cancer. These studies suggest that RBPMS acts as a tumor suppressor gene and that lower levels of RBPMS promote the cisplatin resistance of ovarian cancer cells.

A novel tp53-associated nomogram to predict the overall survival in patients with pancreatic cancer

BACKGROUND

Gene mutations play critical roles in tumorigenesis and cancer development. Our study aimed to screen survival-related mutations and explore a novel gene signature to predict the overall survival in pancreatic cancer.

METHODS

Somatic mutation data from three cohorts were used to identify the common survival-related gene mutation with Kaplan-Meier curves. RNA-sequencing data were used to explore the signature for survival prediction. First, Weighted Gene Co-expression Network Analysis was conducted to identify candidate genes. Then, the ICGC-PACA-CA cohort was applied as the training set and the TCGA-PAAD cohort was used as the external validation set. A TP53-associated signature calculating the risk score of every patient was developed with univariate Cox, least absolute shrinkage and selection operator, and stepwise regression analysis. Kaplan-Meier and receiver operating characteristic curves were plotted to verify the accuracy. The independence of the signature was confirmed by the multivariate Cox regression analysis. Finally, a prognostic nomogram including 359 patients was constructed based on the combined expression data and the risk scores.

RESULTS

TP53 mutation was screened to be the robust and survival-related mutation type, and was associated with immune cell infiltration. Two thousand, four hundred fifty-five genes included in the six modules generated in the WGCNA were screened as candidate survival related TP53-associated genes. A seven-gene signature was constructed: Risk score = (0.1254 × ERRFI1) - (0.1365 × IL6R) - (0.4400 × PPP1R10) - (0.3397 × PTOV1-AS2) + (0.1544 × SCEL) - (0.4412 × SSX2IP) - (0.2231 × TXNL4A). Area Under Curves of 1-, 3-, and 5-year ROC curves were 0.731, 0.808, and 0.873 in the training set and 0.703, 0.677, and 0.737 in the validation set. A prognostic nomogram including 359 patients was constructed and well-calibrated, with the Area Under Curves of 1-, 3-, and 5-year ROC curves as 0.713, 0.753, and 0.823.

CONCLUSIONS

The TP53-associated signature exhibited good prognostic efficacy in predicting the overall survival of PC patients.

Expression and prognostic utility of SSX2IP in patients with nasopharyngeal carcinoma

Cell adhesion affects carcinogenesis, tumor progression, and metastasis. We datamined a published transcriptome (GSE12452) of nasopharyngeal carcinoma (NPC) and identified SSX2IP as a significantly upregulated gene in NPC carcinogenesis among genes associated with cell adhesion (GO:0007155). Consequently, we assessed SSX2IP protein expression and its prognostic significance in 124 patients with NPC using immunohistochemistry and the H-score method. The status of SSX2IP immunoexpression correlated with clinical and pathological characteristics, as well as oncological outcomes. High levels of SSX2IP expression were significantly associated with more advanced primary tumor and TNM stages. Kaplan-Meier and log-rank analyses revealed that high levels of SSX2IP expression, and advanced tumor stage and lymph node metastasis were significantly associated with lower rates of local recurrence-free survival (LRFS), distant metastasis-free survival (DMeFS), and disease-specific (DSS) survival. Multivariate analysis showed that high levels of SSX2IP expression significantly predicted DSS (hazard ratio [HR], 4.290; 95% confidence interval [CI], 2.271-8.102; p < 0.001), DMeFS (HR, 4.159' 95% CI, 2.072-8.345; p < 0.001), and LRFS (HR, 3.007' 95% CI,: 1.418-6.378; p = 0.004). We associated high levels of SSX2IP immunoexpression with aggressive pathological features and worse oncological outcomes, suggesting its potential therapeutic value for patients with NPC.

MORC2, a novel oncogene, is upregulated in liver cancer and contributes to proliferation, metastasis and chemoresistance

Microrchidia 2 (MORC2) is important in DNA damage repair and lipogenesis, however, the clinical and functional role of MORC2 in liver cancer remains to be fully elucidated. The aim the present study was to clarify the role of MORC2 in liver cancer. Expression profile analysis, immunohistochemical staining, reverse transcription-quantitative polymerase chain reaction analysis and western blot analysis were performed to evaluate the levels of MORC2 in liver cancer patient specimens and cell lines; subsequently the expression of MORC2 was suppressed or increased in liver cancer cells and the effects of MORC2 on the cancerous transformation of liver cancer cells were examined in vitro and in vivo. MORC2 was upregulated in liver cancer tissues, and the upregulation was associated with certain clinicopathologic features of patients with liver cancer. MORC2 knockdown caused marked inhibition of liver cancer cell proliferation and clonogenicity, whereas the overexpression of MORC2 substantially promoted liver cancer cell proliferation. In addition, the knockdown of MORC2 inhibited the migratory and invasive ability of liver cancer cells, whereas increased migration and invasion rates were observed in cells with ectopic expression of MORC2. In a model of nude mice, the overexpression of MORC2 promoted tumorigenicity and markedly enhanced pulmonary metastasis of liver cancer. Furthermore, MORC2 regulated apoptosis and its expression level had an effect on the sensitivity of liver cancer cells to doxorubicin, 5-fluorouracil and cisplatin. Mechanically, MORC2 modulated the mitochondrial apoptotic pathway, possibly in a p53-dependent manner, and its dysregulation also resulted in the abnormal activation of the Hippo pathway. For the first time, to the best of our knowledge, the present study confirmed that MORC2 was a novel oncogene in liver cancer. These results provide useful insight into the mechanism underlying the tumorigenesis and progression of liver cancer, and offers clues into potential novel liver cancer therapies.

SSRP1 Contributes to the Malignancy of Hepatocellular Carcinoma and Is Negatively Regulated by miR-497

The aim of this study is to clarify the clinical implication and functional role of structure specific recognition protein 1 (SSRP1) in hepatocellular carcinoma (HCC) and explore the underlying mechanism of aberrant high expression of SSRP1 in cancers. In the present investigation, we validated that SSRP1 was upregulated in HCC samples. We also demonstrated that its upregulation was associated with several clinicopathologic features such as higher serum AFP level, larger tumor size, and higher T stage of HCC patients; and its high expression indicated shorter overall survival and faster recurrence. To investigate the role of SSRP1 in HCC progression, both loss- and gain-function models were established. We demonstrated that SSPR1 modulated both proliferation and metastasis of HCC cells in vitro and vivo. Furthermore, we demonstrated that SSRP1-modulated apoptosis process and its knockdown increased the sensitivity of HCC cells to doxorubicin, 5-Fluorouracil, and cisplatin. We also identified microRNA-497 (miR-497) as a posttranscriptional regulator of SSRP1. Ectopic expression of miR-497 inhibited 3'-untranslated-region–coupled luciferase activity and suppressed endogenous SSRP1 expression at both messenger RNA and protein levels. For the first time, we proved that SSRP1 upregulation contributed to HCC development and the tumor-suppressive miR-497 served as its negative regulator.

Upregulation of Fas in epithelial ovarian cancer reverses the development of resistance to cisplatin

This study was to investigate the role of Fas in the development of Cisplatin-resistant ovarian cancer. On the cellular level, Fas expression was significantly reduced in Cisplatin resistant A2780 (A2780/CP) cells compared with A2780 cells. Fas silence with siRNA would promote tumor cell lines proliferation, facilitate tumor cell cycle transition of G1/S, prevent cell apoptosis, and promote cell migration. Expression of drug resistance gene was negatively correlated to Fas. In nude mice metastasis model of human ovarian carcinoma by subcutaneous transplantation, after Ad-Fas injected intratumorly, we found that upregulation of Fas could inhibit transplantation tumor tissue growth and reduce the expression of drug resistance gene. Our results indicated that upregulation of Fas in epithelial ovarian cancer reversed the development of resistance to Cisplatin. In conclusion, our findings suggested that Fas might act as a promising therapeutic target for improvement of the sensibility to Cisplatin in ovarian cancer. [BMB Reports 2015; 48(1): 30-35]

RUNX3 is a novel negative regulator of oncogenic TEAD-YAP complex in gastric cancer

Runt-related transcription factor 3 (RUNX3) is a well-documented tumour suppressor that is frequently inactivated in gastric cancer. Here, we define a novel mechanism by which RUNX3 exerts its tumour suppressor activity involving the TEAD-YAP complex, a potent positive regulator of proliferative genes. We report that the TEAD-YAP complex is not only frequently hyperactivated in liver and breast cancer, but also confers a strong oncogenic activity in gastric epithelial cells. The increased expression of TEAD-YAP in tumour tissues significantly correlates with poorer overall survival of gastric cancer patients. Strikingly, RUNX3 physically interacts with the N-terminal region of TEAD through its Runt domain. This interaction markedly reduces the DNA-binding ability of TEAD that attenuates the downstream signalling of TEAD-YAP complex. Mutation of RUNX3 at Arginine 122 to Cysteine, which was previously identified in gastric cancer, impairs the interaction between RUNX3 and TEAD. Our data reveal that RUNX3 acts as a tumour suppressor by negatively regulating the TEAD-YAP oncogenic complex in gastric carcinogenesis.

S100A14 promotes the growth and metastasis of hepatocellular carcinoma

BACKGROUND

S100A14 has recently been implicated in the progress of several types of cancers. This study aimed to investigate the clinical significance and possible mechanisms of action of S100A14 in the invasion and metastasis of hepatocellular carcinoma (HCC).

METHODS

S100A14 expression in HCC was detected at mRNA and protein levels and its prognostic significance was assessed. Functional roles of S100A14 in HCC were investigated using MTT, BrdU, wound healing, transwell invasion assay and HCC metastatic mouse model.

RESULTS

S100A14 was significantly elevated in HCC tissues, correlated with multiple tumor nodes, high Edmondson-Steiner grade and vascular invasion. Multivariate Cox analysis showed that the S100A14 expression level was a significant and independent prognostic factor for overall survival (OS) of HCC patients (hazard ratio=1.98, 95% confidence interval=1.14-3.46, P=0.013). S100A14 promoted cell proliferation, invasion and metastasis of HCC in vitro and in vivo.

CONCLUSION

These results suggest S100A14 is a novel prognostic marker and therapeutic target for HCC.

Novel hepatocellular carcinoma molecules with prognostic and therapeutic potentials

Hepatocellular carcinoma (HCC), the predominant form of primary liver cancer, is the sixth most common cancer worldwide and the third leading cause of cancer-related death. The difficulty to diagnose early cancer stages, the aggressive behaviors of HCC, and the poor effectiveness of therapeutic treatments, represent the reasons for the quite similar deaths per year and incidence number. Considering the fact that the diagnosis of HCC typically occurs in the advanced stages of the disease when the therapeutic options have only modest efficacy, the possibility to identify early diagnostic markers could be of significant benefit. So far, a large number of biomarkers have been associated to HCC progression and aggressiveness, but many of them turned out not to be of practical utility. This is the reason why active investigations are ongoing in this field. Given the huge amount of published works aimed at the identification of HCC biomarkers, in this review we mainly focused on the data published in the last year, with particular attention to the role of (1) molecular and biochemical cellular markers; (2) micro-interfering RNAs; (3) epigenetic variations; and (4) tumor stroma. It is worth mentioning that a significant number of the HCC markers described in the present review may be utilized also as targets for novel therapeutic approaches, indicating the tight relation between diagnosis and therapy. In conclusion, we believe that integrated researches among the different lines of investigation indicated above should represent the winning strategies to identify effective HCC markers and therapeutic targets.

Msd1/SSX2IP-dependent microtubule anchorage ensures spindle orientation and primary cilia formation

Anchoring microtubules to the centrosome is critical for cell geometry and polarity, yet the molecular mechanism remains unknown. Here we show that the conserved human Msd1/SSX2IP is required for microtubule anchoring. hMsd1/SSX2IP is delivered to the centrosome in a centriolar satellite-dependent manner and binds the microtubule-nucleator γ-tubulin complex. hMsd1/SSX2IP depletion leads to disorganised interphase microtubules and misoriented mitotic spindles with reduced length and intensity. Furthermore, hMsd1/SSX2IP is essential for ciliogenesis, and during zebrafish embryogenesis, knockdown of its orthologue results in ciliary defects and disturbs left-right asymmetry. We propose that the Msd1 family comprises conserved microtubule-anchoring proteins.

E2A suppresses invasion and migration by targeting YAP in colorectal cancer cells

Background

E2A gene, which encodes two basic helix–loop–helix (bHLH) transcription factors E12 and E47, has been identified as regulator of B lymphoid hematopoiesis and suppressor of lymphoma. E47 protein was found to decrease E-cadherin expression and induce epithelial-mesenchymal transition (EMT). However, the role of E2A in colorectal cancer (CRC) metastasis is still elusive.

Methods

qRT-PCR and semi-qRT-PCR were performed to determine mRNA level of E2A in CRC specimens and colorectal cancer cells. RNAi was employed to downregulate E2A expression and subsequent protein level change was evaluated by immunoblot. Cell invasion and migration capacity were detected by transwell assay using cell culture inserts with or without basement membrane matrix, respectively.

Results

E2A expression was decreased in metastatic CRC tissues. Invasion and migration assays showed downregulation of E2A increased metastatic capacity of CRC cells while forced expression of E12 or E47 could offset this effect. Both E12 and E47 suppressed EMT induced by E2A downregulation. Moreover, Yes-Associated Protein (YAP) was a downstream target of E2A and suppression of YAP inhibited the pro-migration/invasion of E2A deficiency.

Conclusion

Our results suggest that E2A suppresses CRC cell metastasis, at least partially if not all, by inhibiting YAP expression.

Roadblocks to translational advances on metastasis research

Promising advances in cancer therapy stemming from an increasing understanding of the molecular and genetic underpinnings of the tumorigenic process have been fueled by a strong, determined scientific community, influential patient advocacy groups and committed funding bodies. Despite these efforts, the development of effective drugs to prevent systemic dissemination of cancer cells or to eliminate overt metastasis in secondary organs remains a challenge to both researchers and physicians. In an attempt to tackle the most relevant and timely translational issues, a meeting held in 2012 as a result of a successful partnership between the Volkswagen Foundation and Nature Medicine brought together a group of metastasis research experts to identify the most important hurdles and help create a framework for potential clinical and translational strategies.

Cadherin-12 contributes to tumorigenicity in colorectal cancer by promoting migration, invasion, adhersion and angiogenesis

Background

Cadherin 12 (CDH12), which encodes a type II classical cadherin from the cadherin superfamily, may mediate calcium-dependent cell adhesion. It has been demonstrated that CDH12 could play an important role in the invasion and metastasis of salivary adenoid cystic carcinoma. We decided to investigate the relationship between CDH12 expression level and clinicopathologic variables in colorectal carcinoma (CRC) patients and to explore the functions of CDH12 in tumorigenesis in CRC.

Methods

The expression levels of CDH12 in colorectal carcinoma tissues were detected by immunohistochemistry. Real-time PCR and Western Blot were used to screen CDH12 high-expression cell lines. CCK-8 assay was used to detect the proliferation ability of CRC cells being transfected by shRNAs against CDH12. The wound assay and transwell assay were performed to test migration and invasion ability. The importance of CDH12 in cell-cell junctions was detected by cell adhesion assay and cell aggregation assay. Endothelial tube formation assay was used to test the influence of CDH12 on angiogenesis.

Results

Statistical analysis of clinical cases revealed that the positive rate of CDH12 was higher in the CRC tumor tissues compared with the adjacent non-tumor tissues. The expression levels of CDH12 in CRC patients are significantly correlated with invasion depth. Consistently, the ability of proliferation, migration and invasion were suppressed when CDH12 was decreased in CRC cells transfected with shRNAs. Cell adhesion assay and cell aggregation assay presented that tumor cells tend to disperse with the lack of CDH12. Endothelial tube formation assay showed that down-regulation of CDH12 could obviously inhibit the process of angiogenesis, implying that CDH12 may play an important role in tumor metastasis

Conclusion

Our results showed that CDH12 promotes proliferation, migration, invasion, adhesion and angiogenesis, suggesting that CDH12 may be an oncogene in colorectal cancer. CDH12 is expected to become a new diagnostic and prognostic marker and a novel target of the treatment of colorectal cancer.

Epigenetic silencing of miR-338-3p contributes to tumorigenicity in gastric cancer by targeting SSX2IP

MicroRNA has been recently recognized as playing a prominent role in tumorigenesis and metastasis. Here, we report that miR-338-3p was epigenetically silenced in gastric cancer, and its down-regulation was significantly correlated with gastric cancer clinicopathological features. Strikingly, restoring miR-338-3p expression in SGC-7901 gastric cancer cells inhibited proliferation, migration, invasion and tumorigenicity in vitro and in vivo, at least partly through inducing apoptosis. Furthermore, we demonstrate the oncogene SSX2IP is a target of miR-338-3p. We propose that miR-338-3p functions as a tumor suppressor in gastric cancer, and the methylation status of its CpG island could serve as a potential diagnostic marker for gastric cancer.