Interleukin-6 mediates PSAT1 expression and serine metabolism in TSC2-deficient cells.

Tuberous sclerosis complex (TSC) and lymphangioleiomyomatosis (LAM) are caused by aberrant mechanistic Target of Rapamycin Complex 1 (mTORC1) activation due to loss of either TSC1 or TSC2 Cytokine profiling of TSC2-deficient LAM patient-derived cells revealed striking up-regulation of Interleukin-6 (IL-6). LAM patient plasma contained increased circulating IL-6 compared with healthy controls, and TSC2-deficient cells showed up-regulation of IL-6 transcription and secretion compared to wild-type cells. IL-6 blockade repressed the proliferation and migration of TSC2-deficient cells and reduced oxygen consumption and extracellular acidification. U-13C glucose tracing revealed that IL-6 knockout reduced 3-phosphoserine and serine production in TSC2-deficient cells, implicating IL-6 in de novo serine metabolism. IL-6 knockout reduced expression of phosphoserine aminotransferase 1 (PSAT1), an essential enzyme in serine biosynthesis. Importantly, recombinant IL-6 treatment rescued PSAT1 expression in the TSC2-deficient, IL-6 knockout clones selectively and had no effect on wild-type cells. Treatment with anti-IL-6 (αIL-6) antibody similarly reduced cell proliferation and migration and reduced renal tumors in Tsc2+/- mice while reducing PSAT1 expression. These data reveal a mechanism through which IL-6 regulates serine biosynthesis, with potential relevance to the therapy of tumors with mTORC1 hyperactivity.

Membrane-associated RING-CH protein (MARCH8) is a novel glycolysis repressor targeted by miR-32 in colorectal cancer.

BACKGROUND: Colorectal cancer (CRC) is the third most common cancer and leading cause of cancer-related deaths worldwide. Aberrant cellular metabolism is a hallmark of cancer cells, and disturbed metabolism showed clinical significance in CRC. The membrane-associated RING-CH 8 (MARCH8) protein, the first MARCH E3 ligase, plays an oncogenic role and serves as a prognostic marker in multiple cancers, however, the role of MARCH8 in CRC is unclear. In the present study, we aimed to investigate the biomarkers and their underlying mechanism for CRC. METHOD: In this study, we first examined the function of MARCH8 in CRC by analysing public database. Besides, we performing gene silencing studies and generating cellular overexpression and xenograft models. Then its protein substrate was identified and validated. In addition, the expression of MARCH8 was investigated in tissue samples from CRC patients, and the molecular basis for decreased expression was analysed. RESULTS: Systematic analysis reveals that MARCH8 is a beneficial prognostic marker in CRC. In CRC, MARCH8 exhibited tumor-suppressive activity both in vivo and in vitro. Furthermore, we found that MARCH8 is negatively correlated with hexokinase 2 (HK2) protein in CRC patients. MARCH8 regulates glycolysis and promotes ubiquitination-mediated proteasome degradation to reduces HK2 protein levels. Then HK2 inhibitor partially rescues the effect of MARCH8 knockdown in CRC. Poised chromatin and elevated miR-32 repressed MARCH8 expression. CONCLUSION: In summary, we propose that in CRC, poised chromatin and miR-32 decrease the expression of MARCH8, further bind and add ubiquitin, induce HK2 degradation, and finally repress glycolysis to promote tumor suppressors in CRC.

Targeting the NAD+ salvage pathway suppresses APC mutation-driven colorectal cancer growth and Wnt/ß-catenin signaling via increasing Axin level.

BACKGROUND: The role and mechanism of the nicotinamide adenine dinucleotide (NAD+) salvage pathway in cancer cell proliferation is poorly understood. Nicotinamide phosphoribosyltransferase (NAMPT), which converts nicotinamide into NAD+, is the rate-limiting enzyme in the NAD+ salvage pathway. Here, we assessed the role of NAMPT in the proliferation of colorectal cancer. METHODS: Real-time PCR, immunohistochemistry, western blotting, and analyses of datasets from Oncomine and Gene Expression Omnibus were conducted to assess the expression of NAMPT at the mRNA and protein levels in colorectal cancer. The Kaplan Meier plotter online tool was used to evaluate the prognostic role of NAMPT. Knockdown of NAMPT was performed to assess the role of NAMPT in colorectal cancer cell proliferation and tumorigenesis both in vitro and in vivo. Overexpression of NAMPT was used to evaluate impact of NAMPT on colorectal cancer cell proliferation in vitro. NAD+ quantitation, immunofluorescence, dual luciferase assay and western blot were used to explore the mechanism of colorectal cancer proliferation. Transwell migration and invasion assays were conducted to assess the role of NAMPT in cell migration and invasion abilities of colorectal cancer cells. RESULTS: Our study indicated that the inhibition of NAMPT decreased proliferation capacity of colorectal cancer cells both in vitro and in vivo. Conversely, overexpression of NAMPT could promote cell proliferation in vitro. NAMPT inhibition induced ß-catenin degradation by increasing Axin expression levels; this resulted in the inhibition of Wnt/ß-catenin signaling and cell proliferation in colorectal cancer. The addition of nicotinamide mononucleotide, the enzymatic product of NAMPT, effectively reversed ß-catenin protein degradation and inhibited growth. Similarly, the knockdown of Axin also decreased the cell death induced by the inhibition of NAMPT. In addition, we showed that colorectal cancer tissues harbored significantly higher levels of NAMPT than the levels harbored by paired normal tissues, especially in colorectal cancer stages I and II. And the overexpression of NAMPT was associated with unfavorable survival results. CONCLUSIONS: Our findings reveal that NAMPT plays an important role in colorectal cancer proliferation via Wnt/ß-catenin pathway, which could have vital implications for the diagnosis, prognosis and treatment of colorectal cancer.

A meta-analysis of efficacy and safety of S-1 monotherapy or combination therapy as first-line treatment in metastatic colorectal cancer.

PURPOSE: To compare the efficacy and safety profile of S-1-based versus non-S-1-based chemotherapy as first-line treatment in mCRC. METHODS: Relevant randomized controlled trials (RCTs) were obtained from PubMed, Embase, and Ovid databases and the Cochrane library from database set up in May 2018. The RCTs of S-1-based monotherapy or combination therapy as first-line treatment were selected. The impact of S-1-based chemotherapy on progression-free survival (PFS) and overall survival (OS) was assessed by pooling data via RevMan 5.3. RESULTS: Meta-analysis of 10 RCTs showed that S-1-based chemotherapy significantly improved PFS (HR 0.90, 95% CI 0.84-0.97, P = 0.006). In subgroup analysis, there was a statistically significant increase in PFS when S-1-based chemotherapy was compared with 5-FU-based (HR 0.92, 95% CI 0.84-1.00, P = 0.04) or capecitabine-based chemotherapy (HR 0.85, 95% CI 0.73-0.99, P = 0.04). The meta-analysis of OS (HR 0.95, 95% CI 0.86-1.05, P = 0.36), overall response rate (ORR) (HR 0.99, 95% CI 0.84-1.17, P = 0.90), and disease control rate (DCR) (HR 1.61, 95% CI 0.87-3.00, P = 0.13) showed no statistical significance between S-1-based and non-S-1-based chemotherapy. The statistically significant differences in the meta-analysis indicated less incidence of graded 3-4 leucopenia (OR = 0.30, 95% CI 0.13-0.71, P = 0.006) and hand-foot syndrome (HFS) (OR = 0.24, 95% CI 0.10-0.58, P = 0.001) in the S-1-based chemotherapy, and there was no statistically significant difference for other adverse events. CONCLUSIONS: S-1-based chemotherapy in mono or combined therapy was an attractive alternative to standard first-line regimen for patients of mCRC.

Colorectal cancer-derived small extracellular vesicles establish an inflammatory premetastatic niche in liver metastasis.

Liver metastases develop in more than half of the patients with colorectal cancer (CRC) and are associated with a poor prognosis. The factors influencing liver metastasis of CRC are poorly characterized, but this information is urgently needed. We have now discovered that small extracellular vesicles (sEVs; exosomes) derived from CRC can be specifically targeted to liver tissue and induce liver macrophage polarization toward an interleukin-6 (IL-6)-secreting proinflammatory phenotype. More importantly, we found that microRNA-21-5p (miR-21) was highly enriched in CRC-derived sEVs and was essential for creating a liver proinflammatory phenotype and liver metastasis of CRC. Silencing either miR-21 in CRC-sEVs or Toll-like receptor 7 (TLR7) in macrophages, to which miR-21 binds, abolished CRC-sEVs' induction of proinflammatory macrophages. Furthermore, miR-21 expression in plasma-derived sEVs was positively correlated with liver metastasis in CRC patients. Collectively, our data demonstrate a pivotal role of CRC-sEVs in promoting liver metastasis by inducing an inflammatory premetastatic niche through the miR-21-TLR7-IL-6 axis. Thus, sEVs-miR-21 represents a potential prognostic marker and therapeutic target for CRC patients with liver metastasis.

Volcanic phosphorus supply boosted Mesozoic terrestrial biotas in northern China.

The Mesozoic terrestrial Jehol Biota of northern China exceeds the biomass and biodiversity of contemporaneous Lagerstätten. From 135 to 120 Ma, biotic radiation may have responded to the peak destruction of the North China Craton. However, the direct mechanistic link between geological and biological evolution is unclear. Phosphorus (P), a bio-essential nutrient, can be supplied by weathering of volcanics in terrestrial ecosystems. The middle-late Mesozoic volcanic-sedimentary sequences of northern China are amazingly rich in terrestrial organisms. Here we demonstrate episodic increases in P delivery, biological productivity, and species abundance in these strata to reveal the coevolution of volcanism and terrestrial biotas. A massive P supply from the weathering of voluminous volcanic products of craton destruction thus supported a terrestrial environment conducive to the high prosperity of the Jehol Biota. During the nascent stage of craton destruction, such volcanic-biotic coupling can also account for the preceding Yanliao Biota with relatively fewer fossils.

Iodine-Mediated C═C Double Bond Cleavage toward Pyrido[2,1-b]quinazolinones.

A transition-metal-free C═C double bond cleavage reaction employing molecular iodine is described. In the presence of K2CO3 as the base, I2-mediated C═C bond cleavage followed by intramolecular annulation of N-(2-vinylaryl)pyridin-2-amine substrates produces pyrido[2,1-b]quinazolinones and related heterocyclic compounds. This reaction can be completed on a gram scale and has been successfully applied to the synthesis of compounds with important biological properties, including efflux pump inhibitory and antiallergic activities.

ACP-check: An anticancer peptide prediction model based on bidirectional long short-term memory and multi-features fusion strategy.

The anticancer peptide is an emerging anticancer drug that has become an effective alternative to chemotherapy and targeted therapy due to fewer side effects and resistance. The traditional biological experimental method for identifying anticancer peptides is a time-consuming and complicated process that hinders large-scale, rapid, and effective identification. In this paper, we propose a model based on a bidirectional long short-term memory network and multi-features fusion, called ACP-check, which employs a bidirectional long short-term memory network to extract time-dependent information features from peptide sequences, and combines them with amino acid sequence features including binary profile feature, dipeptide composition, the composition of k-spaced amino acid group pairs, amino acid composition, and sequence-order-coupling number. To verify the performance of the model, six benchmark datasets are selected, including ACPred-Fuse, ACPred-FL, ACP240, ACP740, main and alternate datasets of AntiCP2.0. In terms of Matthews correlation coefficients, ACP-check obtains 0.37, 0.82, 0.80, 0.75, 0.56, and 0.86 on six datasets respectively, which is an improvement by 2%-86% than existing state-of-the-art anticancer peptides prediction methods. Furthermore, ACP-check achieves prediction accuracy with 0.91, 0.91, 0.90, 0.87, 0.78, and 0.93 respectively, which increases range from 1%-49%. Overall, the comparison experiment shows that ACP-check can accurately identify anticancer peptides by sequence-level information. The code and data are available at http://www.cczubio.top/ACP-check/.

Ferroptosis regulator FANCD2 is associated with immune infiltration and predicts worse prognosis in lung adenocarcinoma.

Lung adenocarcinoma (LUAD) remains one of the leading causes of cancer-related death. Although immunotherapy has been shown to improve survival in LUAD patients, only a select group of LUAD patients could benefit from it. The correlation between ferroptosis and the tumor immune environment requires further investigation in the setting of LUAD. An analysis using The Cancer Genome Atlas (TCGA)-LUAD cohort systematically evaluated the expression levels of ferroptosis regulators between LUAD and normal tissues and demonstrated the correlation of ferroptosis regulators with the immune checkpoint B7-H3 expression. Based on consensus clustering analysis, we divided LUAD patients into two subtypes according to the expression pattern of ferroptosis regulators. Cluster 2 patients showed more favorable overall survival (OS) (p < 0.001) and disease-free survival (DFS) (p < 0.001) than Cluster 1 patients. CIBERSORT analysis indicated that Cluster 1 patients harbored higher infiltrated levels of uncharacterized cells, CD4+ T cells (nonregulatory), and myeloid dendritic cells, while Cluster 2 patients were more correlated with B cells, M1 macrophages, natural killer cells (NK cells) and regulatory T cells (Tregs). More importantly, we identified FANCD2 as a potentially unfavorable prognostic factor that was overexpressed in LUAD and positively associated with the checkpoint molecule B7-H3 expression. In addition, higher FANCD2 expression was related to a higher tumor immune dysfunction and exclusion (TIDE) score, indicating lower responder rates to cancer immunotherapeutics. In summary, our study suggested a relationship between immune infiltration and ferroptosis and that FANCD2 is a potential biomarker for clinical outcomes and a therapeutic target for LUAD therapy concerning ferroptotic regulation. Our findings may help to advance personalized treatment and improve the prognosis of LUAD.

Patient-Derived Tumor Organoids: New Progress and Opportunities to Facilitate Precision Cancer Immunotherapy.

Cancer immunotherapy has revolutionized the field of cancer treatment in recent years. However, not all patients receiving cancer immunotherapy exhibit durable responses, and reliable, high-throughput testing platforms are urgently needed to guide personalized cancer immunotherapy. The ability of patient-derived tumor organoids to recapitulate pivotal features of original cancer tissues makes them useful as a preclinical model for cancer research and precision medicine. Nevertheless, many challenges exist in the translation of tumor organoid research to clinical decision making. Herein we discuss the applications of patient-derived tumor organoid models and the advances and potential of using complex immune-organoid systems as testing platforms to facilitate precision cancer immunotherapy. In addition, we highlight intriguing applications of tumor organoids with novel multi-omics in preclinical cancer research, highlighting genetic editing, proteomics, and liquid biopsy.

Durable Clinical Response to ALK Tyrosine Kinase Inhibitors in Epithelioid Inflammatory Myofibroblastic Sarcoma Harboring PRRC2B-ALK Rearrangement: A Case Report.

Inflammatory myofibroblastic tumor (IMT) is a rare mesenchymal neoplasm and patients with IMT tend to have a favorable outcome after complete surgical resection. However, some tumors of IMT cases have recurred and grown rapidly after successful surgery. Epithelioid inflammatory myofibroblastic sarcoma (EIMS) is a highly aggressive intra-abdominal IMT variant with epithelioid-to-round cell morphology. Currently, no standard therapy exists for recurrent or invasive IMTs and EIMS, but anaplastic lymphoma kinase (ALK) tyrosine kinase inhibitors (TKIs) are recommended for those harboring ALK gene rearrangements. We herein report the first case of PRRC2B-ALK fusion associated IMTs with clinical and pathological manifestation matched the diagnosis criteria of EIMS and the durable clinical response of the sequential use of ALK TKIs (crizotinib, alectinib, ceritinib, and lorlatinib). A female patient with EIMS of the greater omentum was suffering from a rapid recurrence after cytoreductive surgery was done. Crizotinib was administered when PRRC2B-ALK fusion was detected, and partial response was achieved. The progression-free survival (PFS) of crizotinib was 5 months. Alectinib was administered based on the results of second next-generation sequencing (NGS) analysis, which identified the secondary mutation ALK R1192P. The best overall response of alectinib treatment was a partial response (PR) and the PFS was 5.5 months. Ceritinib was prescribed as third-line therapy after alectinib resistance with ALK L1196M mutation. PR was achieved and the PFS of ceritinib was 6 months. The patient was taking lorlatinib after ceritinib resistance and achieved a stable disease at 2 months with the PFS more than 5 months. The overall survival was more than two years as of the time of manuscript preparation. We describe an EIMS of greater omentum caused by PRRC2B-ALK fusion gene and showed durable clinical response to the sequential use of ALK TKIs.

Cetuximab and vemurafenib plus FOLFIRI (5-fluorouracil/leucovorin/irinotecan) for BRAF V600E-mutated advanced colorectal cancer (IMPROVEMENT): An open-label, single-arm, phase II trial.

BACKGROUND: Current therapeutic regimens for patients with v-raf murine sarcoma viral oncogene homolog B1 (BRAF) V600E-mutated colorectal cancer show unsatisfactory efficacy. To improve outcomes in this area, we assessed the safety and efficacy of a new protocol using vemurafenib and cetuximab combined with FOLFIRI (5-fluorouracil/leucovorin/irinotecan) in patients with BRAF V600E-mutated colorectal cancer. METHODS AND MATERIALS: This was an investigator-initiated, open-label, single-arm, phase II trial conducted in patients with BRAF V600E-mutated advanced colorectal cancer. Patients were eligible to receive FOLFIRI combined with vemurafenib and cetuximab. The primary end-point was the objective response rate, and the secondary end-points included disease control rate, progression-free survival, overall survival and safety. This trial is registered with ClinicalTrials.gov, NCT03727763. RESULTS: Between 12th January 2018, and 18th June 2021, we screened 27 patients, 21 of which were enrolled in this study. Efficacy analysis showed that objective response rates were 81.0% (17/21; 95% confidence interval [CI] 57.4-93.7) in the intention-to-treat population and 85.0% (17/20, 95%CI 61.0-96.0) in the per-protocol population; two patients achieved complete response, and 15 patients achieved a partial response. In the entire cohort, the median progression-free survival was 9.7 months (95%CI 6.3-10.9), and the median overall survival for all patients was 15.4 months (95%CI 8.5-15.4). The most common adverse events (grade 3 to 4) were neutropenia (8/21), anaemia (3/21) and skin rash (3/21). CONCLUSION: Vemurafenib and cetuximab can be safely combined with the FOLFIRI regimen, showing promising antitumour activity and tolerable toxicity in patients with BRAF V600E-mutated advanced colorectal cancer. This regimen warrants a further randomised study in phase III clinical trials.

COVID-19 Pandemic: Advances in Diagnosis, Treatment, Organoid Applications and Impacts on Cancer Patient Management.

Coronavirus disease 2019 (COVID-19) caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread globally and rapidly developed into a worldwide pandemic. The sudden outburst and rapid dissemination of SARS-CoV-2, with overwhelming public health and economic burdens, highlight an urgent need to develop effective strategies for the diagnosis and treatment of infected patients. In this review, we focus on the current advances in the diagnostics and treatment for SARS-CoV-2 infection. Notably, we also summarize some antineoplastic drugs repurposed for COVID-19 treatment and address the diagnostic and therapeutic challenges for oncologists to manage cancer patients in this COVID-19 era. In addition, we emphasize the importance of organoid technology as a valuable experimental virology platform to better understand the pathogenesis of COVID-19 and assist rapid screening of drugs against COVID-19.

The Effects of Differentially-Expressed Homeobox Family Genes on the Prognosis and HOXC6 on Immune Microenvironment Orchestration in Colorectal Cancer.

Background: The homeobox (HOX) gene family encodes highly conserved transcription factors, that play important roles in the morphogenesis and embryonic development of vertebrates. Mammals have four similar HOX gene clusters, HOXA, HOXB, HOXC, and HOXD, which are located on chromosomes 7, 17,12 and 2 and consist of 38 genes. Some of these genes were found to be significantly related to a variety of tumors; however, it remains unknown whether abnormal expression of the HOX gene family affects prognosis and the tumor microenvironment (TME) reshaping in colorectal cancer (CRC). Therefore, we conducted this systematic exploration to provide additional information for the above questions. Methods: RNA sequencing data from The Cancer Genome Atlas (TCGA) and mRNA expression data from Gene Expression Omnibus (GEO) combined with online tumor analysis databases (UALCAN, TIMER, PrognoScan) were utilized to explore the relationship among abnormal expression of HOX family genes, prognosis and the tumor immune microenvironment in CRC. Results: 1. Differential expression and prognosis analysis: 24 genes were significantly differentially expressed in CRC compared to adjacent normal tissues, and seven upregulated genes were significantly associated with poor survival. Among these seven genes, univariate and multivariate Cox regression analysis revealed that only high expression of HOXC6 significantly contributed to poor prognosis; 2. The influence of overexpressed HOXC6 on the pathway and TME: High HOXC6 expression was significantly related to the cytokine pathway and expression of T cell attraction chemokines, the infiltration ratio of immune cells, expression of immune checkpoint markers, tumor mutation burden (TMB) scores and microsatellite instability-high (MSI-H) scores; 3. Stratified analysis based on stages: In stage IV, HOXC6 overexpression had no significant impact on TMB, MSI-H, infiltration ratio of immune cells and response prediction of immune checkpoint blockers (ICBs), which contributed to significantly poor overall survival (OS). Conclusion: Seven differentially expressed HOX family genes had significantly worse prognoses. Among them, overexpressed HOXC6 contributed the most to poor OS. High expression of HOXC6 was significantly associated with high immunogenicity in nonmetastatic CRC. Further research on HOXC6 is therefore worthwhile to provide potential alternatives in CRC immunotherapy.

Special Issues Encountered When Cancer Patients Confront COVID-19.

Since the beginning of the COVID-19 global pandemic, there has been insufficient evidence and experience to help oncologists understand how to deal with infected and non-infected cancer patients. Many hospitals worldwide have shared their experiences of managing such patients by using the internet to reach non-infected cancer patients. However, for infected or suspected infected cancer patients, their experiences in terms COVID-19 diagnosis, anticancer treatment and prognosis are largely unknown and controversial. Here, we summarize the incidence, severe illness rate and mortality according to the published clinical data of COVID-19 in cancer patients and discuss the diagnostic difficulties, anticancer treatment and prognosis of COVID-19-infected cancer patients.

Investigation of Mechanical Properties of Large Shape Memory Alloy Bars under Different Heat Treatments.

Shape memory alloys (SMAs) are a class of functional materials that possess unique thermomechanical properties, such as shape memory effect (SME), superelasticity (SE), damping, and good fatigue and corrosion resistance, which enable them to become ideal materials for applications in earthquake engineering. Numerous studies have shown that the mechanical properties of superelastic SMAs mainly depend on the wire form, or the relationship between the microstructure and thermally induced phase transitions. However, extremely few studies have elucidated the effects of the heat-treatment strategy, size effect of large diameters, and cyclic loading. Herein, the mechanical properties of SMA bars, such as residual strain, energy dissipation, and equivalent damping ratio, were studied with different heat-treatment strategies, cyclic loadings, and strain amplitudes; this was achieved by conducting cyclic tensile tests on SMA bars with four different diameters. The results indicate that the maximum phase transformation stress was obtained with a 14 mm SMA bar subjected to heat treatment at 400 ℃ for 15 min. The mechanical properties were relatively stable after five loading-unloading cycles, which should be considered in engineering applications. The test results provide a mechanical basis for using large SMA bars in self-centering structures in seismic regions.

The Role of Dynamic ctDNA Monitoring During Combination Therapies of BRAF V600E-Mutated Metastatic Colorectal Cancer: A Case Report.

BACKGROUND: BRAF V600E mutation represents a group of colorectal carcinoma with poor prognosis. Although treatment strategies have been recommended after clinical investigations, the progression-free survival is short and unsatisfying. CASE PRESENTATION: Here, we present the case of a 28-year-old male diagnosed with ascending colon adenocarcinoma with multiple liver metastases. Treatment with FOLFIRI plus cetuximab and vemurafenib achieved partial response, following which the patient received conversion surgery with clear resection margin. After disease recurrence, he received combination treatment of nivolumab and regorafenib. Until August 2020, the patient achieved a partial response with more than 12 months progression-free survival. Circulating tumor DNA (ctDNA) was monitored during the patient's treatment. His ctDNA fractions exhibited significant elevation two months before disease progression. As a comparison, the tumor markers were not elevated until the patient was confirmed PD through CT imaging. CONCLUSION: This case exemplifies how liquid biopsy and ctDNA sequencing can aid in real-time molecular characterization of tumors.

Significant prognostic values of differentially expressed-aberrantly methylated hub genes in breast cancer.

Introduction: Abnormal status of gene expression plays an important role in tumorigenesis, progression and metastasis of breast cancer. Mechanisms of gene silence or activation were varied. Methylation of genes may contribute to alteration of gene expression. This study aimed to identify differentially expressed hub genes which may be regulated by DNA methylation and evaluate their prognostic value in breast cancer by bioinformatic analysis. Methods: GEO2R was used to obtain expression microarray data from GSE54002, GSE65194 and methylation microarray data from GSE20713, GSE32393. Differentially expressed-aberrantly methylated genes were identified by FunRich. Biological function and pathway enrichment analysis were conducted by DAVID. PPI network was constructed by STRING and hub genes was sorted by Cytoscape. Expression and DNA methylation of hub genes was validated by UALCAN and MethHC. Clinical outcome analysis of hub genes was performed by Kaplan Meier-plotter database for breast cancer. IHC was performed to analyze protein levels of EXO1 and Kaplan-Meier was used for survival analysis. Results: 677 upregulated-hypomethylated and 361 downregulated-hypermethylated genes were obtained from GSE54002, GSE65194, GSE20713 and GSE32393 by GEO2R and FunRich. The most significant biological process, cellular component, molecular function enriched and pathway for upregulated-hypomethylated genes were viral process, cytoplasm, protein binding and cell cycle respectively. For downregulated-hypermethylated genes, the result was peptidyl-tyrosine phosphorylation, plasma membrane, transmembrane receptor protein tyrosine kinase activity and Rap1 signaling pathway (All p< 0.05). 12 hub genes (TOP2A, MAD2L1, FEN1, EPRS, EXO1, MCM4, PTTG1, RRM2, PSMD14, CDKN3, H2AFZ, CCNE2) were sorted from 677 upregulated-hypomethylated genes. 4 hub genes (EGFR, FGF2, BCL2, PIK3R1) were sorted from 361 downregulated-hypermethylated genes. Differential expression of 16 hub genes was validated in UALCAN database (p<0.05). 7 in 12 upregulated-hypomethylated and 2 in 4 downregulated-hypermethylated hub genes were confirmed to be significantly hypomethylated or hypermethylated in breast cancer using MethHC database (p<0.05). Finally, 12 upregulated hub genes (TOP2A, MAD2L1, FEN1, EPRS, EXO1, MCM4, PTTG1, RRM2, PSMD14, CDKN3, H2AFZ, CCNE2) and 3 downregulated genes (FGF2, BCL2, PIK3R1) contributed to significant unfavorable clinical outcome in breast cancer (p<0.05). High expression level of EXO1 protein was significantly associated with poor OS in breast cancer patients (p=0.03). Conclusion: Overexpression of TOP2A, MAD2L1, FEN1, EPRS, EXO1, MCM4, PTTG1, RRM2, PSMD14, CDKN3, H2AFZ, CCNE2 and downregulation of FGF2, BCL2, PIK3R1 might serve as diagnosis and poor prognosis biomarkers in breast cancer by more research validation. EXO1 was identified as an individual unfavorable prognostic factor. Methylation might be one of the major causes leading to abnormal expression of those genes. Functional analysis and pathway enrichment analysis of those genes would provide novel ideas for breast cancer research.

PTPRB promotes metastasis of colorectal carcinoma via inducing epithelial-mesenchymal transition.

Dysregulation of protein tyrosine phosphatase, receptor type B (PTPRB) correlates with the development of a variety of tumors. Here we show that PTPRB promotes metastasis of colorectal cancer (CRC) cells via inducing epithelial-mesenchymal transition (EMT). We find that PTPRB is expressed at significantly higher levels in CRC tissues compared to adjacent nontumor tissues and in CRC cell lines with high invasion. PTPRB knockdown decreased the number of invasive CRC cells in an in vitro wound healing model, and also reduced tumor metastasis in vivo. Conversely, PTPRB overexpression promoted CRC cell invasion in vitro and metastasis in vivo. PTPRB overexpression decreased vimentin expression and promoted E-cadherin expression, consistent with promotion of EMT, while PTPRB knockdown had the opposite effect. Hypoxic conditions induced EMT and promoted invasion in CRC cells, but these effects were eliminated by PTPRB knockdown. EMT blockade via TWIST1 knockdown inhibited the migration and invasiveness of CRC cells, and even increased PTPRB expression could not reverse this effect. Altogether, these data support the conclusion that PTPRB promotes invasion and metastasis of CRC cells via inducing EMT, and that PTPRB would be a novel therapeutic target for the treatment of CRC.