Dual specific phosphatase 4 suppresses ferroptosis and enhances sorafenib resistance in hepatocellular carcinoma.

AIMS: This investigation aims to elucidate the mechanism underlying sorafenib-induced ferroptosis in hepatocellular carcinoma (HCC). METHODS: The role of dual specificity phosphatase 4 (DUSP4) in sorafenib-treated HCC was investigated using comprehensive assessments both in vitro and in vivo, including Western blotting, qRT-PCR, cell viability assay, lipid reactive oxygen species (ROS) assay, immunohistochemistry, and xenograft tumor mouse model. Additionally, label-free quantitative proteomics was employed to identify potential proteins associated with DUSP4. RESULTS: Our study revealed that suppression of DUSP4 expression heightens the susceptibility of HCC cells to ferroptosis inducers, specifically sorafenib and erastin, in both in vitro and in vivo settings. Furthermore, we identified DUSP4-mediated regulation of key ferroptosis-related markers, such as ferritin light chain (FTL) and ferritin heavy chain 1 (FTH1). Notably, label-free quantitative proteomics unveiled the phosphorylation of threonine residue T148 on YTH Domain Containing 1 (YTHDC1) by DUSP4. Further investigations unraveled that YTHDC1, functioning as an mRNA nuclear export regulator, is a direct target of DUSP4, orchestrating the subcellular localization of FTL and FTH1 mRNAs. Significantly, our study highlights a strong correlation between elevated DUSP4 expression and sorafenib resistance in HCC. CONCLUSIONS: Our findings introduce DUSP4 as a negative regulator of sorafenib-induced ferroptosis. This discovery opens new avenues for the development of ferroptosis-based therapeutic strategies tailored for HCC treatment.

KLF16 enhances stress tolerance of colorectal carcinomas by modulating nucleolar homeostasis and translational reprogramming.

Translational reprogramming is part of the unfolded protein response (UPR) during endoplasmic reticulum (ER) stress, which acts to the advantage of cancer growth and development in different stress conditions, but the mechanism of ER stress-related translational reprogramming in colorectal carcinoma (CRC) progression remains unclear. Here, we identified that Krüppel-like factor 16 (KLF16) can promote CRC progression and stress tolerance through translational reprogramming. The expression of KLF16 was upregulated in CRC tissues and associated with poor prognosis for CRC patients. We found that ER stress inducers can recruit KLF16 to the nucleolus and increase its interaction with two essential proteins for nucleolar homeostasis: nucleophosmin1 (NPM1) and fibrillarin (FBL). Moreover, knockdown of KLF16 can dysregulate nucleolar homeostasis in CRC cells. Translation-reporter system and polysome profiling assays further showed that KLF16 can effectively promote cap-independent translation of ATF4, which can enhance ER-phagy and the proliferation of CRC cells. Overall, our study unveils a previously unrecognized role for KLF16 as an ER stress regulator through mediating translational reprogramming to enhance the stress tolerance of CRC cells and provides a potential therapeutic vulnerability.

TBX20 inhibits colorectal cancer tumorigenesis by impairing NHEJ-mediated DNA repair.

DNA high methylation is one of driving force for colorectal carcinoma (CRC) pathogenesis. Transcription factors (TFs) can determine cell fate and play fundamental roles in multistep process of tumorigenesis. Dysregulation of DNA methylation of TFs should be vital for the progression of CRC. Here, we demonstrated that TBX20, a T-box TF family protein, was downregulated with hypermethylation of promoter in early-stage CRC tissues and correlated with a poor prognosis for CRC patients. Moreover, we identified PDZRN3 as the E3 ubiquitin ligase of TBX20 protein, which mediated the ubiquitination and degradation of TBX20. Furthermore, we revealed that TBX20 suppressed cell proliferation and tumor growth through impairing non-homologous DNA end joining (NHEJ)-mediated double-stranded break repair by binding the middle domain of both Ku70 and Ku80 and therefore inhibiting their recruitment on chromatin in CRC cells. Altogether, our results reveal the tumor-suppressive role of TBX20 by inhibiting NHEJ-mediated DNA repair in CRC cells, and provide a potential biomarker for predicting the prognosis of patients with early-stage CRC and a therapeutic target for combination therapy.

CircLONP2 enhances colorectal carcinoma invasion and metastasis through modulating the maturation and exosomal dissemination of microRNA-17.

BACKGROUND: Metastasis causes the vast majority of colorectal carcinoma (CRC)-related deaths. However, little is known about the specific traits and underlying mechanisms of metastasis-initiating cells in primary CRC. And whether or not circular RNAs (circRNAs) take part in this particular event remain not adequately stated yet. METHODS: A screening method based on Transwell assay was first applied to build CRC subgroups with different metastatic potential. High throughput RNA sequencing was used to find out novel metastatic drivers in CRC metastasis-initiating step. A series of in vitro and in vivo assays were further applied to elucidate the functions and underlying molecular mechanisms of circRNAs in CRC metastasis. RESULTS: A circRNA consisting of exon 8-11 of LONP2, termed as circLONP2, was upregulated in metastasis-initiating CRC subgroups. Aberrant higher expression of circLONP2 was observed in primary CRC tissues with established metastasis, and along the invasive margin in metastatic site. High expression of circLONP2 predicted unfavorable overall survival. Functional studies revealed that circLONP2 could enhance the invasiveness of CRC cells in vitro, and targeting circLONP2 through anti-sense oligonucleotide (ASO) dramatically reduced the penetrance of metastasis to foreign organs in vivo. Mechanically, circLONP2 directly interacted with and promoted the processing of primary microRNA-17 (pri-miR-17), through recruiting DiGeorge syndrome critical region gene 8 (DGCR8) and Drosha complex in DDX1-dependent manner. Meanwhile, upregulated mature miR-17-5p could be assembled into exosomes and internalized by neighboring cells to enhance their aggressiveness. CONCLUSIONS: Our data indicate that circLONP2 acts as key metastasis-initiating molecule during CRC progression through modulating the intracellular maturation and intercellular transfer of miR-17, resulting in dissemination of metastasis-initiating ability in primary site and acceleration of metastasis formation in foreign organs. circLONP2 could serve as an effective prognostic predictor and/or novel anti-metastasis therapeutic target in CRC treatment.

Tumor necrosis as a poor prognostic predictor on postoperative survival of patients with solitary small hepatocellular carcinoma.

BACKGROUND: Small hepatocellular carcinoma (sHCC) is a special subtype of HCC with the maximum tumor diameter ≤ 3 cm and excellent long-term outcomes. Surgical resection or radiofrequency ablation provides the greatest chance for cure; however, many patients still undergo tumor recurrence after primary treatment. To date, there is no clinical applicable method to assess biological aggressiveness in solitary sHCC. METHODS: In the current study, we retrospectively evaluated tumor necrosis of 335 patients with solitary sHCC treated with hepatectomy between December 1998 and 2010 from Sun Yat-sen University Cancer Center. RESULTS: The presence of tumor necrosis was observed in 157 of 335 (46.9%) sHCC patients. Further correlation analysis showed that tumor necrosis was significantly correlated with tumor size and vascular invasion (P = 0.026, 0.003, respectively). The presence of tumor necrosis was associated closely with poorer cancer-specific overall survival (OS) and recurrence-free survival (RFS) as evidenced by univariate (P <  0.001; hazard ratio, 2.821; 95% CI, 1.643-4.842) and multivariate analysis (P = 0.005; hazard ratio, 2.208; 95% CI, 1.272-3.833). Notably, the combined model by tumor necrosis, vascular invasion and tumor size can significantly stratify the risk for RFS and OS and improve the ability to discriminate sHCC patients' outcomes (P <  0.0001 for both). CONCLUSIONS: Our results provide evidence that tumor necrosis has the potential to be a parameter for cancer aggressiveness in solitary sHCC. The combined prognostic model may be a useful tool to identify solitary sHCC patients with worse outcomes.

Prognostic Role of the Immunoscore for Patients with Urothelial Carcinoma of the Bladder Who Underwent Radical Cystectomy.

BACKGROUND: Increasing evidence suggests that cancer progression is strongly influenced by the host immune response, which is represented by immune cell infiltrates. The T-lymphocyte-based Immunoscore is reported to be a reliable prognostic factor in colon cancer, but its significance in urothelial carcinoma of the bladder (UCB) is at an early stage of exploration. This study aimed to determine whether the tumor immune infiltrate, as evaluated by the Immunoscore, could act as a useful prognostic marker for UCB patients who have undergone radical cystectomy (RC). METHODS: In this study, immunohistochemistry was used to examine the Immunoscore of 221 UCB patients who underwent RC. The Immunoscore of the patients was determined by the densities of CD3+ and CD8+ T cells at the tumor center and the invasive margin. RESULTS: A highly significant association between a low Immunoscore and a shortened patient survival (P < 0.001, log-rank test) was demonstrated. In different subsets of UCB patients, a low Immunoscore also was a prognostic indicator of pT ≤ 2, pN(-)-status tumors, negative vascular invasion, or both (P < 0.05). Importantly, the Immunoscore together with the patient's pT status provided significant independent prognostic parameters in the multivariate analysis (P < 0.05). Furthermore, a significant correlation (P = 0.003) of a low Immunoscore with an increased UCB labeling index of Ki-67 (a cell proliferation marker) was observed in this UCB cohort. CONCLUSIONS: The findings suggest that the Immunoscore, as examined by immunohistochemistry, might serve as a novel prognostic marker for UCB patients who have undergone RC.

Correction to: Prognostic Role of the Immunoscore for Patients with Urothelial Carcinoma of the Bladder Who Underwent Radical Cystectomy.

In the original article, the word IMMUNOSCORE® was not displayed to reflect its trademark status. At every mention, IMMUNOSCORE® should be in all caps and with a registered trademark symbol.

Eukaryotic Initiation Factor 5A2 Contributes to the Maintenance of CD133(+) Hepatocellular Carcinoma Cells via the c-Myc/microRNA-29b Axis.

Cancer stem cells (CSCs)/cancer-initiating cells (CICs) are suggested responsible for driving cancer resistance to conventional therapies and for cancer recurrence and/or metastasis. CD133 is served as a key biomarker to identify and characterize this subpopulation of cells in hepatocellular carcinoma (HCC). Our previous study indicated that overexpression of eukaryotic initiation factor 5A2 (EIF5A2) promotes HCC cell metastasis and angiogenesis. In this study, we demonstrated that EIF5A2 might play a crucial role in CSCs regulation and investigated its potential molecular mechanisms. Using quantitative real-time polymerase chain reaction assay, we observed that the expression of EIF5A2 positively correlated with CD133 levels in a cohort of cancerous and noncancerous liver tissues and cells. Next, HCC cells with high expression of EIF5A2 have a strong capacity to form undifferentiated tumor spheres in vitro and show elevated levels of stem cell-related genes, leading to an increased ability to develop tumors when subcutaneously injected into nude mice. Furthermore, differential microRNA expression was profiling between two EIF5A2-depleted HCC cell lines and their control one identified a decreased expression of miR-29b in EIF5A2-depleted cell lines. Further functional studies illustrated that downregulated miR-29b level is responsible for EIF5A2-maintained HCC cell stemness either in vitro or in vivo. Moreover, enforced expression of EIF5A2 in HCC cells largely enhanced the binding of c-Myc on the promoter of miR-29b and downregulation of miR-29b by EIF5A2 was dependent on c-Myc. Our findings, collectively, reveal that EIF5A2 contributes to the maintenance of CD133+ HCC cells via the c-Myc/miR-29b axis. Stem Cells 2018;36:180-191.

CLDN14 is epigenetically silenced by EZH2-mediated H3K27ME3 and is a novel prognostic biomarker in hepatocellular carcinoma.

Trimethylation of lysine 27 on histone H3 (H3K27ME3) is a transcription-suppressive histone mark mediated by enhancer of zeste homolog 2 (EZH2). We have previously suggested that EZH2-mediated H3K27ME3 plays a critical oncogenic role in human hepatocellular carcinoma (HCC) aggressiveness. However, the direct downstream targets of EZH2-H3K27ME3 and the molecular mechanisms by which regulates HCC pathogenesis remain unclear. In this study, we used chromatin immunoprecipitation together with high-throughput sequencing (ChIP-seq) and gene expression profiling by microarray analysis to assess genome-wide chromatin occupancy of H3K27ME3 in HCC cells. We identified that claudin14 (CLDN14) is a potentially direct target for EZH2-mediated H3K27ME3 in HCC. In a large cohort of clinical HCC tissues, we found that low expression of CLDN14 was significantly associated with advanced tumor stage and determined to be an independent predictor of shortened survival of HCC patients. Next, functional experiment demonstrated that depletion of CLDN14 substantially restored EZH2-silenced HCC cells motility and invasive capacities and supported cell epithelial-mesenchymal transition (EMT). Furthermore, downregulation of CLDN14 dramatically re-enhanced the wnt/ß-catenin signaling activity in EZH2-silenced HCC cells by increasing the levels of active ß-catenin and promoting the nuclear localization of ß-catenin. These results, collectively, uncover that CLDN14 is a novel direct target of EZH2-mediated H3K27ME3, and provide an explanation for the aggressive nature of HCC with downregulation of CLDN14 and the underling mechanism that links the tumor suppressor CLDN14 to the wnt/ß-catenin signaling pathway.

Intrahepatic cholangiocarcinoma prognostic determination using pre-operative serum C-reactive protein levels.

BACKGROUND: Serum C-reactive protein (CRP), an acute inflammatory response biomarker, has been recognized as an indicator of malignant disease progression. However, the prognostic significance of CRP levels collected before tumor removal in intrahepatic cholangiocarcinoma requires further investigation. METHODS: We sampled the CRP levels in 140 patients with intrahepatic cholangiocarcinoma who underwent hepatectomies with regional lymphadenectomies between 2006 and 2013. A retrospective analysis of the clinicopathological data was performed. We focused on the impact of serum CRP on the patients' cancer-specific survival and recurrence-free survival rates. RESULTS: High levels of preoperative serum CRP were significantly associated with well-established clinicopathologic features, including gender, advanced tumor stage, and elevated carcinoembryonic antigen and carbohydrate antigen 19-9 levels (P < 0.05). Univariate analysis demonstrated a significant association between high levels of serum CRP and adverse cancer-specific survival (P = 0.001) and recurrence-free survival (P < 0.001). In patients with stage I/II intrahepatic cholangiocarcinoma, the serum CRP level was a prognostic indicator for cancer-specific survival. In patients with stage I/II or stage III/IV, the serum CRP level was a prognostic indicator for recurrence-free survival (P < 0.05). Additionally, multivariate analysis identified serum CRP level in intrahepatic cholangiocarcinoma as an independent prognostic factor (P < 0.05). CONCLUSIONS: We confirmed a significant association of elevated pre-operative CRP levels with poor clinical outcomes for the tested patients with intrahepatic cholangiocarcinoma. Our results indicate that the serum CRP level may represent a useful factor for patient stratification in intrahepatic cholangiocarcinoma management.

The prognostic significance of tyrosine-protein phosphatase nonreceptor type 12 expression in nasopharyngeal carcinoma.

Tyrosine-protein phosphatase nonreceptor type 12 (PTPN12) has been proposed to predict prognosis of various human cancers. However, the clinicopathologic and prognostic significance of PTPN12 expression in NPC has not yet been elucidated. The objective of this study was to investigate the clinicopathological and prognostic implication of PTPN12 in nasopharyngeal carcinoma (NPC) patients. Protein expression levels of PTPN12 were explored by semiquantitative immunohistochemical staining on archival formalin-fixed, paraffin-embedded pathological specimens consisting of 203 NPCs, and 40 normal nasopharyngeal mucosa tissues. Receiver operating characteristic (ROC) curve analysis was employed to determine the cutoff score of PTPN12 expression in NPCs. The PTPN12 immunohistochemical staining results were then correlated with various clinicopathological features and patients' prognosis using various statistical models. Our results showed that decreased expression of PTPN12 was more frequently observed in NPC tissues compared with the normal nasopharyngeal mucosa. Further correlation analyses indicated that the decreased expression of PTPN12 was significantly associated with tumor T classification, N classification, distant metastasis, and clinical stage in NPCs (P < 0.05). Univariate analysis showed a significant association between the decreased expression of PTPN12 and adverse overall survival and disease-free survival (P < 0.05). More importantly, multivariate analysis identified the PTPN12 expression in NPC as an independent prognostic factor. The decrease expression of PTPN12 might be important in conferring a more aggressive behavior in NPC. Thus, PTPN12 expression may be used as a novel independent prognostic biomarker for patients with NPC.

Overexpression of CIP2A is an independent prognostic indicator in nasopharyngeal carcinoma and its depletion suppresses cell proliferation and tumor growth.

BACKGROUND: Cancerous inhibitor of protein phosphatase 2A (CIP2A) is an oncoprotein that acts as a prognostic marker for several human malignancies. In this study, we investigated the clinical significance of CIP2A and its function in nasopharyngeal carcinoma (NPC). METHODS: Quantitative RT-PCR, western blot, and immunohistochemistry analyses were used to quantify CIP2A expression in NPC cell lines and clinical samples. Kaplan-Meier curves were used to estimate the association between CIP2A expression and patient survival. The functional role of CIP2A in NPC cell lines was evaluated by small interfering RNA-mediated depletion of the protein followed by analyses of cell proliferation and xenograft growth. RESULTS: CIP2A levels were upregulated in NPC cell lines and clinical samples at both the mRNA and protein levels (P < 0.01). Patients with high CIP2A expression had poorer overall survival (HR, 1.98; 95% CI, 1.16-3.34; P = 0.01) and poorer disease-free survival (HR, 1.68; 95% CI, 1.07-2.62; P = 0.02) rates than patients with low CIP2A expression. In addition, CIP2A expression status was an independent prognostic indicator for NPC patients. The depletion of CIP2A expression inhibited c-Myc protein expression in NPC cell lines, suppressed cell viability, colony formation, and anchorage-independent growth in vitro, and inhibited xenograft tumor growth in vivo. CONCLUSIONS: Our data demonstrate that high CIP2A expression in patients was associated with poor survival in NPC, and depletion of CIP2A expression inhibited NPC cell proliferation and tumor growth. Thus, these results warrant further investigation of CIP2A as a novel therapeutic target for the treatment of NPC.

The prognostic effect of perineural invasion in esophageal squamous cell carcinoma.

BACKGROUND: Perineural invasion (PNI) is correlated with adverse survival in several malignancies, but its significance in esophageal squamous cell carcinoma (ESCC) remains to be clearly defined. The objective of this study was to determine the association between PNI status and clinical outcomes. METHODS: We retrospectively evaluated the PNI of 433 patients with ESCC treated with surgery between 2000 and 2007 at a single academic center. The resulting data were analyzed using Spearman's rank correlation, the Kaplan-Meier method, Cox proportional hazards regression modeling and Harrell's concordance index (C-index). RESULTS: PNI was identified in 209 of the 433 (47.7%) cases of ESCC. The correlation analysis demonstrated that PNI in ESCC was significantly correlated with tumor differentiation, infiltration depth, pN classification and stage (P < 0.05). The five-year overall survival rate was 0.570 for PNI-negative tumors versus 0.326 for PNI-positive tumors. Patients with PNI-negative tumors exhibited a 1.7-fold increase in five-year recurrence-free survival compared with patients with PNI-positive tumors (0.531 v 0.305, respectively; P < 0.0001). In the subset of patients with node-negative disease, PNI was evaluated as a prognostic predictor as well (P < 0.05). In the multivariate analysis, PNI was an independent prognostic factor for overall survival (P = 0.027). The C-index estimate for the combined model (PNI, gender and pN status) was a significant improvement on the C-index estimate of the clinicopathologic model alone (0.739 v 0.706, respectively). CONCLUSIONS: PNI can function as an independent prognostic factor of outcomes in ESCC patients, and the PNI status in primary ESCC specimens should be considered for therapy stratification.

NEIL1 drives the initiation of colorectal cancer through transcriptional regulation of COL17A1.

Deficiency of DNA repair pathways drives the development of colorectal cancer. However, the role of the base excision repair (BER) pathway in colorectal cancer initiation remains unclear. This study shows that Nei-like DNA glycosylase 1 (NEIL1) is highly expressed in colorectal cancer (CRC) tissues and associated with poorer clinical outcomes. Knocking out neil1 in mice markedly suppresses tumorigenesis and enhances infiltration of CD8+ T cells in intestinal tumors. Furthermore, NEIL1 directly forms a complex with SATB2/c-Myc to enhance the transcription of COL17A1 and subsequently promotes the production of immunosuppressive cytokines in CRC cells. A NEIL1 peptide suppresses intestinal tumorigenesis in ApcMin/+ mice, and targeting NEIL1 demonstrates a synergistic suppressive effect on tumor growth when combined with a nuclear factor κB (NF-κB) inhibitor. These results suggest that combined targeting of NEIL1 and NF-κB may represent a promising strategy for CRC therapy.

Mex-3 RNA binding family member A (MEX3A)/circMPP6 complex promotes colorectal cancer progression by inhibiting autophagy.

RNA-binding proteins (RBPs)-RNA networks have contributed to cancer development. Circular RNAs (circRNAs) are considered as protein recruiters; nevertheless, the patterns of circRNA-protein interactions in colorectal cancer (CRC) are still lacking. Processing bodies (PBs) formed through liquid-liquid phase separation (LLPS) are membrane-less organelles (MLOs) consisting of RBPs and RNA. Previous evidence suggests a connection between PBs dynamics and cancer progression. Despite the increasingly acknowledged crucial role of RBPs and RNA in the accumulation and maintenance of MLOs, there remains a lack of specific research on the interactions between PBs-related RBPs and circRNAs in CRC. Herein, we identify that MEX-3 RNA binding family member A (MEX3A), frequently upregulated in CRC tissues, predicts poorer patient survival. Elevated MEX3A accelerates malignance and inhibits autophagy of CRC cells. Importantly, MEX3A undergoes intrinsically disordered regions (IDRs)-dependent LLPS in the cytoplasm. Specifically, circMPP6 acts as a scaffold to facilitate the interaction between MEX3A and PBs proteins. The MEX3A/circMPP6 complex modulates PBs dynamic and promotes UPF-mediated phosphodiesterase 5A (PDE5A) mRNA degradation, consequently leading to the aggressive properties of CRC cells. Clinically, CRC patients exhibiting high MEX3A expression and low PDE5A expression have the poorest overall survival. Our findings reveal a collaboration between MEX3A and circMPP6 in the regulation of mRNA decay through triggering the PBs aggregation, which provides prognostic markers and/or therapeutic targets for CRC.

The "stone-like" pattern of LC3A expression and its clinicopathologic significance in hepatocellular carcinoma.

Autophagy is an evolutionarily conserved process that involves lysosomal degradations of cellular organelles. Microtubule-associated protein 1 light chain 3A (LC3A), an autophagic gene, is differentially expressed in human cancers. However, the relationship between LC3A expression and hepatocellular carcinoma (HCC) has not been investigated. Tissue microarray-based immunohistochemistry was used to examine the expression patterns of LC3A in HCC. The resulting data were analyzed using receiver operating characteristic curves, Spearman's rank correlation, Kaplan-Meier plots and Cox proportional hazards regression modeling. Two distinct patterns of LC3A expression were observed in HCC: "stone-like" structuring and diffuse cytoplasmic expression. High levels of LC3A expression were more frequently observed in HCC tissues compared to the adjacent non-tumorous tissue. Correlation analyses indicated that high expression of the "stone-like" LC3A was correlated with greater levels of serum AFP, poorer tumor differentiation and the presence of vascular invasion. Kaplan-Meier survival analysis showed a significant association between high expression of the "stone-like" LC3A and unfavorable prognosis (P<0.001). Importantly, multivariate analysis (P<0.05) identified the "stone-like" expression of LC3A in HCC as an independent prognostic factor. Collectively, our data provide compelling evidence that "stone-like" expression of LC3A plays an important role in HCC progression and may act as a biomarker of prognosis for patients with HCC.

STAG2 Regulates Homologous Recombination Repair and Sensitivity to ATM Inhibition.

Stromal antigen 2 (STAG2), a subunit of the cohesin complex, is recurrently mutated in various tumors. However, the role of STAG2 in DNA repair and its therapeutic implications are largely unknown. Here it is reported that knockout of STAG2 results in increased double-stranded breaks (DSBs) and chromosomal aberrations by reducing homologous recombination (HR) repair, and confers hypersensitivity to inhibitors of ataxia telangiectasia mutated (ATMi), Poly ADP Ribose Polymerase (PARPi), or the combination of both. Of note, the impaired HR by STAG2-deficiency is mainly attributed to the restored expression of KMT5A, which in turn methylates H4K20 (H4K20me0) to H4K20me1 and thereby decreases the recruitment of BRCA1-BARD1 to chromatin. Importantly, STAG2 expression correlates with poor prognosis of cancer patients. STAG2 is identified as an important regulator of HR and a potential therapeutic strategy for STAG2-mutant tumors is elucidated.

High-expression of ZBP-89 correlates with distal metastasis and poor prognosis of patients in clear cell renal cell carcinoma.

ZBP-89, a Krüppel-type zinc-finger transcription factor, is found to participate in tumor development, invasion and metastasis. However, the expression status of ZBP-89 in clear cell renal cell carcinoma (CCRCC) remains elusive. Using quantitative real-time-PCR and Western Blot, we found that, in fresh cancer tissues, ZBP-89 was remarkably decreased in 79.2% (19/24) and 83.3% (5/6) of CCRCC at mRNA and protein level, respectively. Immunohistochemistry also revealed a significant decline of ZBP-89 expression in CCRCC, showing that low expression of ZBP-89 was present in 73.9% (105/142) of tumorous tissues but in 48.1% (52/108) of the corresponding adjacent kidney tissues. Furthermore, ZBP-89 expression in CCRCC was significantly correlated with several clinicopathological features, including TNM stage (P=0.005) and distal metastasis (P=0.001). Further study confirmed that ZBP-89 expression was markedly higher in metastatic CCRCC than that in non-metastatic tissue (P=0.002). In addition, CCRCC patients with low ZBP-89 expression survived longer than those with high ZBP-89 expression, as indicated by the result of univariate analysis (P<0.0001). More importantly, multivariate analysis revealed that ZBP-89 was an independent predictor of overall survival (HR, 2.871; 95% CI, 1.409-5.853; P=0.004). Collectively, our study provides vigorous evidence that ZBP-89 was significantly downregulated in CCRCC and could be served as a promising biomarker for prediction of distal metastasis and prognosis of patient with CCRCC.

Overexpression of the secretory small GTPase Rab27B in human breast cancer correlates closely with lymph node metastasis and predicts poor prognosis.

BACKGROUND: The secretory small GTPase Rab27b was recently identified as an oncogene in breast cancer (BC) in vivo and in vitro studies. This research was designed to further explore the clinical and prognostic significance of Rab27B in BC patients. METHODS: The mRNA/protein expression level of Rab27B was examined by performing Real-time PCR, western blot, and immunohistochemistry (IHC) assays in 12 paired BC tissues and matched adjacent noncancerous tissues (NAT). Then we carried out IHC assay in a large cohort of 221 invasive BC tissues, 22 normal breast tissues, 40 fibroadenoma (FA), 30 ductual carcinoma in situ (DCIS) and 40 metastatic lymph nodes (LNs). The receiver operating characteristic curve method was applied to obtain the optimal cutoff value for high Rab27B expression. Epithelial-mesenchymal transition (EMT) marker expression levels were detected in relation to Rab27B expression. RESULTS: We observed that the increased expression of Rab27B was dependent upon the magnitude of cancer progression (P < 0.001). The elevated expression of Rab27B was closely correlated with lymph node metastasis, advanced clinical stage, ascending pathology classification, and positive ER status. Furthermore, patients with high expression of Rab27B had inferior survival outcomes. Multivariate Cox regression analysis proved that Rab27B was a significantly independent risk factor for patients' survival (P < 0.001). Furthermore, a significant positive relationship was observed between Rab27B expression and elevated mesenchymal EMT markers. CONCLUSION: Our findings suggest that overexpression of Rab27B in BC coincides with lymph node metastasis and acquisition of a poor prognostic phenotype.