Exploring prognostic values of DNA ploidy, stroma-tumor fraction and nucleotyping in stage II colon cancer patients.

PURPOSE: To assess the prognostic value of three novel biomarkers, DNA ploidy, stroma-tumor fraction, and nucleotyping, seeking for more accurate stratification in stage II colon cancer. METHODS: A total of 417 patients with complete follow up information were enrolled in this study and divided into three clinical risk groups. IHC was performed to examine MSI status. DNA ploidy, stroma and nucleotyping were estimated using automated digital imaging system. Kaplan-Meier survival curves, Cox proportional hazards regression models, and correlation analyses were carried out to process our data. RESULTS: In the whole cohort of stage II colon cancer, nucleotyping and DNA ploidy were significant prognostic factors on OS in univariate analyses. The combination of nucleotyping and DNA ploidy signified superior OS and DFS. Difference was not significant between low-stroma and high-stroma patients. In multivariable analyses, nucleotyping and the combination of nucleotyping and DNA ploidy were proven the dominant contributory factors for OS. In the low-risk group, we found the combination of nucleotyping and DNA ploidy as the independent prognostic factor statistically significant in both univariate and multivariable, while in the high-risk group, the nucleotyping. CONCLUSIONS: Our study has proven nucleotyping and the combination of DNA ploidy and nucleotyping as independent prognostic indicators, thus expanding the application of nucleotyping as a predictor from high risk stage II colon cancer to whole risks.

Anti-PRL-3 Monoclonal Antibody inhibits the Growth and Metastasis of colorectal adenocarcinoma.

Background: Colon cancer is the one of leading causes of cancer-related death. Chemotherapy, radiotherapy and immunotherapy will be the mainstream in inoperable advanced cancer in clinics. Precision treatment is still lack in colon cancer. Materials and Methods: We developed a series of mAbs targeting PRL-3 through different types of immunogens. The binding domains of mAbs were identified through the ELISA and Western blotting experiments. The antitumor activity of mAbs was verified by cell proliferation, migration and invasion experiments. Xenograft subcutaneous and metastatic models and patient derived Xenograft (PDX) model were established. Results: mAb 12G12 targeting 77-120AA exhibited inhibition in migration and invasion experiments. 12G12 inhibited the migration of multiple types of cancer cells, including colon cancer, gastric cancer, esophagus cancer, liver cancer, lung cancer and pancreatic cancer cells. 12G12 decreased the tumor growth and metastasis in Xenograft subcutaneous and metastatic tumor model, respectively. The antitumor activity of mAb 12G12 was also confirmed in PDX model of gastric cancer. PRL-3 interacted with Golgi protein TMED10. Knockdown of TMED10 expression attenuated the cell migration triggered by purified GST-PRL-3 protein. Conclusion: Our results confirmed the antitumor activity of mAb 12G12 in colorectal adenocarcinoma and provided a new potential targeted therapy of colon cancer.

KRAS, NRAS, BRAF signatures, and MMR status in colorectal cancer patients in North China.

We assessed the clinicopathological features and prognostic values of KRAS, NRAS, BRAF, and DNA mismatch repair status in colorectal cancer (CRC) to provide real-world data in developing countries. We enrolled 369 CRC patients and analyzed the correlation between RAS/BRAF mutation, mismatch repair status with clinicopathological features, and their prognostic roles. The mutation frequencies of KRAS, NRAS, and BRAF were 41.7%, 1.6%, and 3.8%, respectively. KRAS mutations and deficient mismatch repair (dMMR) status were associated with right-sided tumors, aggressive biological behaviors, and poor differentiation. BRAF (V600E) mutations are associated with well-differentiated and lymphovascular invasion. The dMMR status predominated in young and middle-aged patients and tumor node metastasis stage II patients. dMMR status predicted longer overall survival in all CRC patients. KRAS mutations indicated inferior overall survival in patients with CRC stage IV. Our study showed that KRAS mutations and dMMR status could be applied to CRC patients with different clinicopathological features.

Lynch syndrome pre-screening and comprehensive characterization in a multi-center large cohort of Chinese patients with colorectal cancer.

OBJECTIVE: Lynch syndrome (LS) pre-screening methods remain under-investigated in colorectal cancers (CRCs) in Asia. Here, we aimed to systematically investigate LS pre-screening and comprehensively characterize LS CRCs. METHODS: Microsatellite instability (MSI) and germline variants of DNA mismatch repair (MMR) genes were examined in 406 deficient MMR (dMMR) and 250 proficient MMR CRCs. The genetic differences between LS and sporadic CRCs were studied with whole exome sequencing analysis. RESULTS: The incidence of dMMR in Chinese patients with CRCs was 13.8%. Consistency analysis between MMR immunohistochemistry (IHC) and MSI testing showed the kappa value was 0.758. With next-generation sequencing (NGS), germline variants were detected in 154 CRCs. Finally, 88 patients with CRC were identified as having LS by Sanger sequencing. Among them, we discovered 21 previously unreported pathogenic germline variants of MMR genes. Chinese patients with LS, compared with sporadic CRCs, tended to be early-onset, right-sided, early-stage and mucinous. Overall, the performance of MMR IHC and MSI testing for LS pre-screening was comparable: the area under the ROC curve for dMMR, MSI-H, and MSI-H/L was 0.725, 0.750, and 0.745, respectively. dMMR_MSI-H LS and sporadic CRCs showed substantial differences in somatic genetic characteristics, including different variant frequencies of APC, CREBBP, and KRAS, as well as different enriched pathways of VEGF, Notch, TGFßR, mTOR, ErbB, and Rac protein signal transduction. CONCLUSIONS: MMR IHC and MSI testing were effective methods for LS pre-screening. The revealed clinical and somatic genetic characteristics in LS CRCs may have the potential to improve the performance of LS pre-screening in combination with dMMR/MSI.

Folate-Receptor Positive Circulating Tumor Cell Is a Potential Diagnostic Marker of Prostate Cancer.

Folate-receptor positive circulating tumor cells (FR+CTCs) shows an important role in the diagnosis and dynamic monitoring for many solid tumors; however, the application of FR+CTCs in prostate cancer remains unclear. We explored the potential application of FR+CTCs in this retrospective study. The levels of FR+CTCs were detected in 30 prostate cancer patients and 7 bladder cancer patients in Peking University Cancer Hospital from August 2017 to August 2021. Clinical and pathology data were collected. One-way ANOVA was used to compare the difference in FR+CTCs levels in patients with prostate cancer, bladder cancer, and benign disease. The area under the receiver operating curve (AUROC) was used to compare the accuracy of FR+CTCs and tPSA in the diagnosis of prostate cancer. We found that levels of FR+CTCs were significantly higher in cancer patients (both prostate and bladder cancer) than in patients with benign urinary disease (p < 0.001). Besides, FR+CTCs level was consistently high in the prostate cancer patients with different tPSA levels (p < 0.001), and it was significantly higher in the patients with f/tPSA levels <0.16 than in those patients with f/tPSA levels >0.16 (12.20 ± 1.31 vs. 8.73 ± 0.92 FU/3 ml, p = 0.043). The diagnosis efficiency of FR+CTCs is better than the tPSA in prostate cancer patients with tPSA <10 ng/ml (0.871 vs. 0.857). In the prostate cancer patients with tPSA <10 ng/ml and f/tPSA <0.16, a combination of FR+CTCs and tPSA (AUROC, 0.934) further increased the diagnosis efficiency of each of these biomarkers alone (FR+CTCs, 0.912; tPSA, 0.857). Therefore, FR+CTCs could serve as an early diagnosis marker in the prostate cancer patients with uncertain tPSA levels.

PTP4A3 Is a Prognostic Biomarker Correlated With Immune Infiltrates in Papillary Renal Cell Carcinoma.

PTP4A3 plays an important role in the tumorigenesis and metastasis of multiple tumors, but its prognostic role in renal cancer is not well understood. We utilized the Oncomine and Tumor Immunoassay Resource databases to examine the differential expression of PTP4A3 in tumor tissues and normal tissues in breast, urinary tract, gastrointestinal tract and skin. Using the GEPIA and PrognoScan databases, the independent prognostic role of PTP4A3 was confirmed in clear cell renal cell cancer and papillary renal cell cancer. Expression of PTP4A3 were obviously higher in tumor tissue compare with normal tissues (P=0.028). We haven't found the associations of PTP4A3 and clinicopathological features in our IHC cohort. Ectopic expression of PTP4A3 promotes proliferation, migration and invasion and increased the mRNA level of TGFB1 in RCC cell lines. Immunohistochemical staining indicated that the expression of PTP4A3 associates with CD3+ (P =0.037)/CD8+ (P =0.037) intratumor TILs, not with invasive margins in renal cancer. Comprehensive analysis of immune infiltration in the TIMER database correlated PTP4A3 expression with the infiltration of B cells, CD8+ T cells, CD4+ T cells and neutrophils in both clear cell renal cell carcinoma and papillary renal cell carcinoma. PTP4A3 expression was associated with the infiltration of dendritic cells in papillary renal cell carcinoma. We further confirmed that the infiltration of B cells and CD8+ T cells was associated with poor prognosis in papillary renal cell carcinoma patients, consistent with the prognostic role of PTP4A3 in papillary renal cell carcinoma. PTP4A3 expression correlated genes involved in B cells, monocytes, M1 macrophages, Th2 and Treg cells in papillary renal cell carcinoma. These results suggest PTP4A3 as a prognostic factor with a role in regulating immune cell infiltration in papillary renal cell carcinoma.

An integrated classifier improves prognostic accuracy in non-metastatic gastric cancer.

The American Joint Committee on Cancer (AJCC) staging system is insufficiently prognostic for gastric cancer (GC) patients and complementary factors are in urgent need. Here we aimed to develop a comprehensive model, consisting of both immune signatures and cancer signaling molecules, which was expected to accurately improve survival prediction in non-metastatic gastric cancer (GC). We first validated the prognostic value of a combination of 18 immune features and 52 cancer-signaling molecules in The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) database. Then, their expression and distribution were analyzed in consecutive 1180 GC patients using immunohistochemistry. We developed and validated a novel protein-based prognostic classifier using CDH1, an epithelial-mesenchymal transition (EMT) marker, and five immune features (CD3, CD4, CD274, GZMB, and PAX5) by Cox regression model with group LASSO penalty. We observed significant differences in the overall survival of the high- and low-prognostic risk groups (66.8% VS 27.0%, P < .001). A combination of this classifier with age and pTNM stage had better prognostic value than pTNM alone. The model was further validated in both treatment-naive patients and those treated with neoadjuvant chemotherapy. Moreover, GC patients with high-risk score exhibited a favorable prognosis to adjuvant chemotherapy. This integrated classifier could be automatically analyzed and effectively predict survival of GC patients and may provide a new clinically applicable strategy to identify patients who are more likely to benefit from adjuvant chemotherapy.

FOXM1 functions collaboratively with PLAU to promote gastric cancer progression.

Background: Gastric cancer (GC) is one of the main mortality cause worldwide. Previously, we found Forkhead box protein (FOXM1) or Urokinase-type plasminogen activator (PLAU) are independent prognostic markers of GC. This study aims to explore the combining prognostic efficacy and the potential insights underlying additive effect of FOXM1 to PLAU in GC progression through in-silico analyses. Method: The expression of FOXM1 and PLAU were profiled in 33 cancer types using public data. A merged GC expression dataset containing 598 samples was used for evaluating prognostic significance of FOXM1/PLAU. Gene Set Enrichment Analysis (GSEA) was performed to elucidate the mechanisms underlying FOXM1/PLAU promoted GC progression. The Cancer Genome Atlas (TCGA) was used for analyzing the association between FOXM1/PLAU and tumor immune infiltration. Genomic and proteomic differences between FOXM1+PLAU+ and FOXM1-PLAU- groups were also computed using TCGA GC data. Drugs targeting FOXM1/PLAU associated gene expression pattern was analyzed using LINCs database. Results: FOXM1 and PLAU are overexpressed in 17/33 cancer types including GC. Kaplan-Meier analyses indicate that the FOXM1+PLAU+ subgroup have the worst prognosis, while FOXM1-PLAU- subgroup have the best survival. Bioinformatics analysis indicated that FOXM1+PLAU+ associated genes are enriched in TGF-beta, DNA repair and drug resistance signaling pathways; FOXM1 and PLAU expression are negatively correlated with tumor immune infiltration. Genomic and proteomic differences between FOXM1+PLAU+ and FOXM1-PLAU- groups were presented. Data mining from LINCs suggested several chemicals or drugs that could target the gene expression pattern of FOXM1+PLAU+ patients. Conclusion: FOXM1+PLAU+ can serve as effective prognostic biomarkers and potential therapeutic targets for GC. Due to the additive effect of these two genes, screening for drugs or chemicals that targeting the expression patterns PLAU+FOXM1+ subgroup may exert important clinical impact on GC management.

Characterization of TP53 mutations in Pap test DNA of women with and without serous ovarian carcinoma.

OBJECTIVE: Pap tests hold promise as a molecular diagnostic for serous ovarian cancer, but previous studies reported limited sensitivity. Furthermore, the presence of somatic mutations in normal tissue is increasingly recognized as a challenge to the specificity of mutation-based cancer diagnostics. We applied an ultra-deep sequencing method with the goal of improving sensitivity and characterizing the landscape of low-frequency somatic TP53 mutations in Pap tests. METHODS: We used CRISPR-DS to deeply sequence (mean Duplex depth ~3000×) the TP53 gene in 30 Pap tests from 21 women without cancer and 9 women with serous ovarian carcinoma with known TP53 driver mutations. Mutations were annotated and compared to those in the TP53 cancer database. RESULTS: The tumor-derived mutation was identified in 3 of 8 Pap tests from women with ovarian cancer and intact tubes. In addition, 221 low-frequency (≲0.001) exonic TP53 mutations were identified in Pap tests from women with ovarian cancer (94 mutations) and without ovarian cancer (127 mutations). Many of these mutations resembled TP53 mutations found in cancer: they impaired protein activity, were predicted to be pathogenic, and clustered in exons 5 to 8 and hotspot codons. Cancer-like mutations were identified in all women but at higher frequency in women with ovarian cancer. CONCLUSIONS: Pap tests have low sensitivity for ovarian cancer detection and carry abundant low-frequency TP53 mutations. These mutations are more frequently pathogenic in women with ovarian cancer. Determining whether low-frequency TP53 mutations in normal gynecologic tissues are associated with an increased cancer risk warrants further study.

PRL-3 Promotes Ubiquitination and Degradation of AURKA and Colorectal Cancer Progression via Dephosphorylation of FZR1.

The oncogenic phosphatase PRL-3 is highly expressed in metastatic colorectal cancer but not in nonmetastatic colorectal cancer or noncolorectal cancer metastatic cancers. Although the proinvasive capacity of PRL-3 has been validated in multiple types of cancer, its impact on colorectal cancer progression and the underlying mechanisms remain poorly understood. Here, we report that overexpressed PRL-3 stimulates G2-M arrest, chromosomal instability (CIN), self-renewal, and growth of colorectal cancer cells in xenograft models, while colorectal cancer cell proliferation is decreased. PRL-3-induced G2-M arrest was associated with decreased expression of Aurora kinase A (AURKA). PRL-3-promoted slow proliferation, CIN, self-renewal, and growth in xenografts were counteracted by ectopic expression of AURKA. Conversely, knockdown of PRL-3 resulted in low proliferation, S-phase arrest, impaired self-renewal, increased apoptosis, and diminished xenograft growth independently of AURKA. Analysis of colorectal cancer specimens showed that expression of PRL-3 was associated with high status of CIN and poor prognosis, which were antagonized by expression of AURKA. PRL-3 enhanced AURKA ubiquitination and degradation in a phosphatase-dependent fashion. PRL-3 interacted with AURKA and FZR1, a regulatory component of the APC/CFZR1 complex. Destabilization of AURKA by PRL-3 required PRL-3-mediated dephosphorylation of FZR1 and assembly of the APC/CFZR1 complex. Our study suggests that PRL-3-regulated colorectal cancer progression is collectively determined by distinct malignant phenotypes and further reveals PRL-3 as an essential regulator of APC/CFZR1 in controlling the stability of AURKA. SIGNIFICANCE: Dephosphorylation of FZR1 by PRL-3 facilitates the activity of APC/CFZR1 by destabilizing AURKA, thus influencing aggressive characteristics and overall progression of colorectal cancer.

Knockdown of PRL-3 increases mitochondrial superoxide anion production through transcriptional regulation of RAP1.

BACKGROUND: Phosphatase of regenerating liver-3 (PRL-3) has been shown to be highly expressed in various types of cancers and is related to poor prognosis. Our previous study showed that silencing of PRL-3 leads to increased reactive oxygen species (ROS). However, the mechanism of PRL-3 regulating ROS is not clear. MATERIALS AND METHODS: PRL-3 or Repressor activator protein 1 (RAP1) was knockdown in human colorectal cancer cell lines HCT116 and SW480. The mRNA level was measured by quantitative real-time (qRT)-PCR and the protein level was measured by western blot. ROS was detected by specific oxidationsensitive fluorescent probes. Cell cycle was analyzed through flow cytometry. Luciferase assay and chromatin immunoprecipitation (ChIP) were performed to investigate the regulation of RAP1 by PRL-3. Gene expression correlation was analyzed through an interactive web server. Statistical analysis was performed with SPSS software. RESULTS: Knockdown of PRL-3 significantly increases mitochondrial superoxide anion, mitochondria membrane potential, and induces cell cycle arrest. Decreased PRL-3-induced mitochondrial superoxide anion accumulation is related to the downregulation of RAP1, which could also affect the level of mitochondria superoxide anion. PRL-3 regulates the expression of RAP1 through binding to the promoter of rap1 gene. PRL-3 could regulate the expression of peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC-1α) through the mediation of RAP1. Both PRL-3 and RAP1 could regulate the expression of manganese superoxide dismutase 2 (SOD2) and the uncoupling protein 2 (UCP2), which may be related to PRL-3 suppression induced mitochondria superoxide anion. CONCLUSION: Our study presents the first evidence that PRL-3 is involved in the regulation of mitochondria superoxide anion as a transcriptional factor.

Targeted genome fragmentation with CRISPR/Cas9 enables fast and efficient enrichment of small genomic regions and ultra-accurate sequencing with low DNA input (CRISPR-DS).

Next-generation sequencing methods suffer from low recovery, uneven coverage, and false mutations. DNA fragmentation by sonication is a major contributor to these problems because it produces randomly sized fragments, PCR amplification bias, and end artifacts. In addition, oligonucleotide-based hybridization capture, a common target enrichment method, has limited efficiency for small genomic regions, contributing to low recovery. This becomes a critical problem in clinical applications, which value cost-effective approaches focused on the sequencing of small gene panels. To address these issues, we developed a targeted genome fragmentation approach based on CRISPR/Cas9 digestion that produces DNA fragments of similar length. These fragments can be enriched by a simple size selection, resulting in targeted enrichment of up to approximately 49,000-fold. Additionally, homogenous length fragments significantly reduce PCR amplification bias and maximize read usability. We combined this novel target enrichment approach with Duplex Sequencing, which uses double-strand molecular tagging to correct for sequencing errors. The approach, termed CRISPR-DS, enables efficient target enrichment of small genomic regions, even coverage, ultra-accurate sequencing, and reduced DNA input. As proof of principle, we applied CRISPR-DS to the sequencing of the exonic regions of TP53 and performed side-by-side comparisons with standard Duplex Sequencing. CRISPR-DS detected previously reported pathogenic TP53 mutations present as low as 0.1% in peritoneal fluid of women with ovarian cancer, while using 10- to 100-fold less DNA than standard Duplex Sequencing. Whether used as standalone enrichment or coupled with high-accuracy sequencing methods, CRISPR-based fragmentation offers a simple solution for fast and efficient small target enrichment.

Sarsaparilla (Smilax Glabra Rhizome) Extract Activates Redox-Dependent ATM/ATR Pathway to Inhibit Cancer Cell Growth by S Phase Arrest, Apoptosis, and Autophagy.

Sarsaparilla (Smilax Glabra Rhizome) exerts growth inhibitory effect on multiple cancer cells in vitro and in vivo, and redox-dependent persistent activation of ERK1/2 has been reported to underlie this effect. Here, we report an activation of ATM/ATR-dependent signaling pathway also as a mechanism for the cancer cell growth inhibition induced by the supernatant fraction of the water-soluble extract from sarsaparilla (SW). SW treatment (3.5 µg/µL) promoted the phosphorylations of ATM, ATR, and CHK1 in AGS and HT-29 cells. The ATM kinase inhibitor, KU55933, could reverse SW-induced ERK phosphorylation but not the reduced glutathione/oxidized glutathione (GSH/GSSG) imbalance in AGS cells. However, both the redox inhibitor glutathione (GSH) and ERK inhibitor U0126 antagonized SW-induced phosphorylations of ATM, ATR, and CHK1 in AGS cells. We further found KU55933 significantly antagonized SW-induced S phase arrest, apoptosis, autophagy and the resultant cell growth inhibition. Our results provide another molecular basis for the anticancer action of sarsaparilla.

PRL-3 promotes telomere deprotection and chromosomal instability.

Phosphatase of regenerating liver (PRL-3) promotes cell invasiveness, but its role in genomic integrity remains unknown. We report here that shelterin component RAP1 mediates association between PRL-3 and TRF2. In addition, TRF2 and RAP1 assist recruitment of PRL-3 to telomeric DNA. Silencing of PRL-3 in colon cancer cells does not affect telomere integrity or chromosomal stability, but induces reactive oxygen species-dependent DNA damage response and senescence. However, overexpression of PRL-3 in colon cancer cells and primary fibroblasts promotes structural abnormalities of telomeres, telomere deprotection, DNA damage response, chromosomal instability and senescence. Furthermore, PRL-3 dissociates RAP1 and TRF2 from telomeric DNA in vitro and in cells. PRL-3-promoted telomere deprotection, DNA damage response and senescence are counteracted by disruption of PRL-3-RAP1 complex or expression of ectopic TRF2. Examination of clinical samples showed that PRL-3 status positively correlates with telomere deprotection and senescence. PRL-3 transgenic mice exhibit hallmarks of telomere deprotection and senescence and are susceptible to dextran sodium sulfate-induced colon malignancy. Our results uncover a novel role of PRL-3 in tumor development through its adverse impact on telomere homeostasis.

Repressor activator protein 1-promoted colorectal cell migration is associated with the regulation of Vimentin.

Repressor activator protein 1 plays important roles in telomere protection, while repressor activator protein 1 binds to extra-telomeric DNA and exerts the function as a transcriptional regulator. Previous study showed that repressor activator protein 1 regulates the transcriptional activity of nuclear factor-κB, and it was highly expressed in breast cancer tissues; however, the clinical significance of repressor activator protein 1 expression in cancer remains to be elucidated. In this study, we discovered that repressor activator protein 1 was highly expressed in colorectal cancer tissues. High expression of repressor activator protein 1 was significantly correlated with poor prognosis and distant metastasis. Knockdown of repressor activator protein 1 in colorectal cancer cells did not affect cell proliferation or colony formation, but dramatically decreased cell migration and F-actin-enriched membrane protrusions. Microarray screening revealed that Vimentin was downregulated after repressor activator protein 1 knockdown, which was validated by analysis of a colorectal cancer dataset. Furthermore, knockdown of Vimentin attenuated repressor activator protein 1-enhanced cell migration. Thus, our study suggests that repressor activator protein 1 is a prognostic marker and a potential target for colorectal cancer therapy.

Antibody Array Revealed PRL-3 Affects Protein Phosphorylation and Cytokine Secretion.

Phosphatase of regenerating liver 3 (PRL-3) promotes cancer metastasis and progression via increasing cell motility and invasiveness, however the mechanism is still not fully understood. Previous reports showed that PRL-3 increases the phosphorylation of many important proteins and suspected that PRL-3-enhanced protein phosphorylation may be due to its regulation on cytokines. To investigate PRL-3's impact on protein phosphorylation and cytokine secretion, we performed antibody arrays against protein phosphorylation and cytokines separately. The data showed that PRL-3 could enhance tyrosine phosphorylation and serine/threonine phosphorylation of diverse signaling proteins. Meanwhile, PRL-3 could affect the secretion of a subset of cytokines. Furthermore, we discovered the PRL-3-increased IL-1α secretion was regulated by NF-κB and Jak2-Stat3 pathways and inhibiting IL-1α could reduce PRL-3-enhanced cell migration. Therefore, our result indicated that PRL-3 promotes protein phosphorylation by acting as an 'activator kinase' and consequently regulates cytokine secretion.

PRL-3 promotes cell adhesion by interacting with JAM2 in colon cancer.

Phosphatase of regenerating liver-3 (PRL-3), also termed PTP4A3, is a metastasis-related protein tyrosine phosphatase. Its expression levels are significantly correlated with the progression and survival of a wide range of malignant tumors. However, the mechanism by which PRL-3 promotes tumor invasion and metastasis is not clear. In the present study, the functions of PRL-3 were systemically analyzed in the key events of metastasis including, motility and adhesion. A cell wounding assay, cell spread assay and cell-matrix adhesion assay were carried out to analyze the cell movement and cell adhesion ability of colon cancer, immunoprecipitation and immunofluorescence assay was confirmed the interaction of PRL-3 and JAM2. It was demonstrated that PRL-3 promoted the motility of Flp-In-293 and LoVo colon cancer cells and increased the distribution of cell skeleton proteins on the cell protrusions. In addition, stably expressing PRL-3 reduced the spreading speed of colon cancer cells and cell adhesion on uncoated, fibronectin-coated and collagen I-coated plates. Mechanistically, junction adhesion molecular 2 (JAM2) was identified as a novel interacting protein of PRL-3. The findings of the present study revealed the roles of PRL-3 in cancer cell motility and adhesion process, and provided information on the possibility of PRL-3 increase cell-cell adhesion by associating with JAM2.

Potential options for managing LOX+ ER- breast cancer patients.

Overexpression of lysyl oxidase (LOX) is often observed in estrogen receptor negative (ER-) breast cancer patients with bone metastasis. In the present bioinformatics study, we observed that LOX is a prognostic factor for poor progression free survival in patients with ER- breast cancer. LOX overexpression was positively correlated with resistance to radiation, doxorubin and mitoxantrone, but negatively correlated with resistance to bisphosphonate, PARP1 inhibitors, cisplatin, trabectedin and gemcitabine. LOX overexpression was also associated with EMT and stemness of cancer cells, which leads to chemotherapeutic resistance and poor outcome in ER- patients. Although we suggest several therapeutic interventions that may help in the management of LOX+ ER- breast cancer patients, experiments to validate the function of LOX in ER- breast cancer are still needed.

Unconventional secretion of synuclein-γ promotes tumor cell invasion.

Synuclein-γ (SNCG) is a chaperone protein and exists mainly in the cytoplasm. SNCG confers chemoresistance, and is a potential unfavorable biomarker for multiple types of cancer. Our previous work demonstrated that SNCG could be detected in the serum of cancer patients and the medium of cultured cancer cells, but the mechanism of SNCG secretion and its biological roles are unknown. Here, we showed that SNCG levels in the culture medium were positively correlated with cancer cell densities and the concentrations of fetal bovine serum added. SNCG secretion was unaffected by brefeldin A, an inhibitor of the classic protein transport pathway, but was antagonized by exosome inhibitor, lysosome inhibitor, ABC transporter inhibitor, and phosphatidylinositide 3-kinase inhibitor, and knockdown of Rab27a. Ultracentrifugation fractionation revealed that intracellular SNCG was present as both free and vesicle-associated forms, but that the extracellular SNCG was mainly free. The results of reciprocal coimmunoprecipitation experiments showed an interaction between SNCG and flotillin-2, a marker of exosomes and lipid rafts. Moreover, we demonstrated that SNCG, both secreted from tumor cells and exogenously added, markedly promoted cancer cell migration and invasion, but had no effect on noncancerous cells. These findings suggest that SNCG is actively secreted by cancer cells via an unconventional secretion pathway and contributes to aggressive phenotypes of cancer cells.

Phosphatase of regenerating liver-3 (PRL-3) is associated with metastasis and poor prognosis in gastric carcinoma.

BACKGROUND: PRL-3 is a member of phosphatases of regenerating liver family, characterized by phosphatase active domain and C-terminal prenylation motif. Overexpression of PRL-3 has been implicated in multiple cancers. Here we examined the clinical significance of PRL-3 in gastric cancer together with its metastatic biological functions utilizing different structural mutants. METHODS: PRL-3 expression was analyzed immunohistochemically in 196 gastric cancer patients and 21 cases of liver metastasis. A series of wild type PRL-3 or its mutant plasmids were expressed in BGC823 cells to investigate the relationship between its catalytic activity, cellular localization and metastatic potential in vitro. RESULTS: Positive staining of PRL-3 was observed in 19.4% (38/196) gastric cancer tissues compared with 76.2% (16/21) in liver metastasis. Statistical analysis revealed that PRL-3 expression correlated with lymph node metastasis and vascular invasion (P<0.05). Patients with high PRL-3 expression showed poorer 5-year overall survival (P=0.011). Wild type PRL-3 expressing cells resulted in enhanced migration and invasion ability, which were greatly crippled in form of PRL-3(C104S) or PRL-3(ΔCAAX) mutants accompanied with its alteration in subcellular localization. CONCLUSIONS: Metastasis associated protein PRL-3 may serve as a potential prognostic biomarker in human gastric cancer. Both the phosphatase catalytic activity and cellular localization are critical for its function.