Breast cancer is a heterogeneous disease, and triple-negative breast cancer (TNBC) continues to be a serious health problem. The potential involvement of lncRNAs in TNBC progression remains unexplored. Here, we demonstrated that LINC01638 is highly expressed in TNBC tissues and cells. LINC01638 maintains the mesenchymal traits of TNBC cells, including an enriched epithelial-mesenchymal transition (EMT) signature and cancer stem cell-like state. LINC01638 knockdown suppresses tumor proliferation and metastasis both in vitro and in vivo. LINC01638 overexpression predicts a poor outcome of breast cancer patients. Mechanistically, LINC01638 interacts with c-Myc to prevent SPOP-mediated c-Myc ubiquitination and degradation. C-Myc transcriptionally enhances MTDH (metadherin) expression and subsequently activates Twist1 expression to induce EMT. Our findings describe LINC01638-mediated signal transduction and highlight the crucial role of LINC01638 in TNBC progression.

Recently, emerging evidence has suggested that long noncoding RNAs (lncRNAs) have crucial roles in cancer progression. Here, we demonstrated that the lncRNA MIR4435-2HG was highly expressed in lung cancer tissues and correlated with histological grades and lymph node metastasis. Phenotypic analysis indicated that MIR4435-2HG knockdown inhibited lung cancer cell proliferation and invasion in vitro and in vivo. Notably, MIR4435-2HG knockdown suppressed the EMT (epithelial-mesenchymal transition) process and cancer stem cell traits of lung cancer cells. Mechanistically, MIR4435-2HG knockdown decreased the transactivation of β-catenin. MIR4435-2HG interacted with β-catenin and thus prevented its degradation by the proteasome system. Our findings highlight the important roles and mechanisms of MIR4435-2HG in lung cancer progression. High expression of lncRNA MIR4435-2HG correlates with lung cancer progression MIR4435-2HG promotes lung cancer cells proliferation and invasion MIR4435-2HG knockdown suppresses the EMT process and cancer stem cell traits MIR4435-2HG knockdown inhibits the β-catenin signalling.

Breast cancer stem cells (BCSCs) are tumor initiating cells that can self-renew and are highly tumorigenic and chemoresistant. Therefore, the identification of factors critical for BCSC function is vital for the development of therapies. Here, we report that DNMT1-mediated FOXO3a promoter hypermethylation leads to downregulation of FOXO3a expression in breast cancer. FOXO3a is functionally related to the inhibition of FOXM1/SOX2 signaling and to the consequent suppression of BCSCs properties and tumorigenicity. Moreover, we found that SOX2 directly transactivates DNMT1 expression and thereby alters the methylation landscape, which in turn feedback inhibits FOXO3a expression. Inhibition of DNMT activity suppressed tumor growth via regulation of FOXO3a/FOXM1/SOX2 signaling in breast cancer. Clinically, we observed a significant inverse correlation between FOXO3a and FOXM1/SOX2/DNMT1 expression levels, and loss of FOXO3a expression or increased expression of FOXM1, SOX2, and DNMT1 predicted poor prognosis in breast cancer. Collectively, our findings suggest an important role of the DNMT1/FOXO3a/FOXM1/SOX2 pathway in regulating BCSCs properties, suggesting potential therapeutic targets for breast cancer.

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Patients with triple-negative breast cancers (TNBC) are at a high risk for a recurrent or metastatic disease, and the molecular mechanisms associated with this risk are unclear. Proteoglycan serglycin (SRGN) proteins are involved in tumor metastasis, but their role in TNBC has not yet been elucidated. This study investigates the SRGN gene expression and how it regulates TGFβ2 and the downstream signaling of TGFβ2 in TNBC cells and tissues. Our results show that SRGN mRNA and protein expression levels were significantly higher in TNBC cell lines and tumor tissues than that in non-TNBC cells and tissues. We inhibited SRGN expression and protein secretion using shRNA and we observed this inhibited the invasive motility of TNBC cancer cells in vitro and metastasis of TNBC cancer cells in vivo. SRGN protein treatment increased the expression and secretion of transforming growth factor-β2 (TGFβ2) by activating CD44/CREB1 signaling and promoted epithelial-to-mesenchymal transition in TNBC cells. Moreover, TGFβ2 treatment increased the mRNA and protein expression of the SRGN gene by activating Smad3 to target the SRGN relative promoter domain in TNBC cells. Our findings demonstrate that SRGN interacts with TGFβ2 which regulates TNBC metastasis via the autocrine and paracrine routes. SRGN could serve as a potential target for development of agents or therapeutics for the TNBC.

Because of their high tumor specificity and immunogenicity, neoantigens have been considered as ultimate targets for cancer immunotherapy. Neoantigen-based vaccines have demonstrated promising efficacy for several cancer types. To further investigate the antitumor potentials for other types of solid tumors, we designed a peptide-based neoantigen vaccine, iNeo-Vac-P01, and conducted a single-arm, open-labeled, investigator-initiated clinical trial (NCT03662815).Patients and Methods: Personalized neoantigen vaccines were designed and manufactured according to our bioinformatics analysis results from the whole-exome sequencing of tumor and peripheral blood cell DNAs. Patients were scheduled to be vaccinated subcutaneously with adjuvant on days 1, 4, 8, 15, and 22 (prime phase), and days 78 and 162 (boost phase). Additional immunizations were administrated every 2-3 months as per patient's potential benefit. The safety and efficacy were assessed through adverse events (AE), progression-free survival (PFS), overall survival (OS), and other parameters.Results: Of the 22 patients enrolled with advanced malignancies, 20 had no or mild AEs, while 2 had grade 3 or 4 acute allergic reactions only after their sixth boost vaccination. The disease control rate was 71.4%. The median PFS was 4.6 months, whereas the median OS was not reached (12-month OS ¼ 55.1%). Around 80% of individual peptides or peptide pools elicited measurable specific immune response. In addition, our findings revealed several potential biomarkers for the prediction of better response.Conclusions: iNeo-Vac-P01 as monotherapy is feasible and safe for patients with advanced solid tumors. It could elicit T-cellmediated immune response targeting tumor neoantigens, and might have promising antitumor efficacy.See related commentary by Filderman and Storkus, p.

Non-small cell lung carcinoma (NSCLC) is a major cancer type whose epigenetic alteration remains unclear. We analyzed open chromatin data with matched whole-genome sequencing and RNA-seq data of 50 primary NSCLC cases. We observed high interpatient heterogeneity of open chromatin profiles and the degree of heterogeneity correlated to several clinical parameters. Lung adenocarcinoma and lung squamous cell carcinoma (LUSC) exhibited distinct open chromatin patterns. Beyond this, we uncovered that the broadest open chromatin peaks indicated key NSCLC genes and led to less stable expression. Furthermore, we found that the open chromatin peaks were gained or lost together with somatic copy number alterations and affected the expression of important NSCLC genes. In addition, we identified 21 joint-quantitative trait loci (joint-QTL) that correlated to both assay for transposase accessible chromatin sequencing peak intensity and gene expression levels. Finally, we identified 87 regulatory risk loci associated with lung cancer-related phenotypes by intersecting the QTLs with genome-wide association study significant loci. In summary, this compendium of multiomics data provides valuable insights and a resource to understand the landscape of open chromatin features and regulatory networks in NSCLC.Significance: This study utilizes state of the art genomic methods to differentiate lung cancer subtypes.

Metastasis remains the major obstacle to improved survival for breast cancer patients. Downregulation of FOXO3a transcription factor in breast cancer is causally associated with the development of metastasis through poorly understood mechanisms. Here, we report that FOXO3a is functionally related to the inhibition of VEGF-A/NRP1 signaling and to the consequent suppression of breast cancer metastasis. We show that FOXO3a directly induces miR-29b-2 and miR-338 expression. Ectopic expression of miR-29b-2/miR-338 significantly suppresses EMT, migration/invasion, and in vivo metastasis of breast cancer. Moreover, we demonstrate that miR-29b-2 directly targets VEGF-A while miR-338 directly targets NRP1, and show that regulation of miR-29b-2 and miR-338 mediates the ability of FOXO3a to suppress VEGF-A/NRP1 signaling and breast cancer metastasis. Clinically, our results show that the FOXO3a-miR-29b-2/miR-338-VEGF-A/NRP1 axis is dysregulated and plays a critical role in disease progression in breast cancer. Collectively, our findings propose that FOXO3a functions as a metastasis suppressor, and define a novel signaling axis of FOXO3a-miRNA-VEGF-A/NRP1 in breast cancer, which might be potential therapeutic targets for breast cancer.