miR-181c-5p/DERL1 pathway controls breast cancer progression mediated by TRAF6-linked K63 ubiquitination of AKT.

BACKGROUND: Aberrant Derlin-1 (DERL1) expression is associated with an overactivation of p-AKT, whose involvement in breast cancer (BRCA) development has been widely speculated. However, the precise mechanism that links DERL1 expression and AKT activation is less well-studied. METHODS: Bioinformatic analyses hold a promising approach by which to detect genes' expression levels and their association with disease prognoses in patients. In the present work, a dual-luciferase assay was employed to investigate the relationship between DERL1 expression and the candidate miRNA by both in vitro and in vivo methods. Further in-depth studies involving immunoprecipitation-mass spectrum (IP-MS), co-immunoprecipitation (Co-IP), as well as Zdock prediction were performed. RESULTS: Overexpression of DERL1 was detected in all phenotypes of BRCA, and its knockdown showed an inhibitory effect on BRCA cells both in vitro and in vivo. The Cancer Genome Atlas (TCGA) database reported that DERL1 overexpression was correlated with poor overall survival in BRCA cases, and so the quantification of DERL1 expression could be a potential marker for the clinical diagnosis of BRCA. On the other hand, miR-181c-5p was downregulated in BRCA, suggesting that its overexpression could be a potent therapeutic route to improve the overall survival of BRCA cases. Prior bioinformatic analyses indicated a somewhat positive correlation between DERL1 and TRAF6 as well as between TRAF6 and AKT, but not between miR-181c-5p and DERL1. In retrospect, DERL1 overexpression promoted p-AKT activation through K63 ubiquitination. DERL1 was believed to directly interact with the E3 ligase TRAF6. As Tyr77Ala or Tyr77Ala/Gln81Ala/Arg85Ala/Val158Ala attempts to prevent the interaction between DERL1 and TRAF domain of TRAF6, resulted in a significant reduction in K63-ubiquitinated p-AKT production. However, mutations in Gln81Ala, Arg85Ala, or Val158Ala could possibly interrupt with these processes. CONCLUSIONS: Our data confirm that mediation of the miR-181c-5p/DERL1 pathway by TRAF6-linked AKT K63 ubiquitination holds one of the clues to set our focus on toward meeting the therapeutic goals of BRCA.

METTL1/WDR4-mediated m7G tRNA modifications and m7G codon usage promote mRNA translation and lung cancer progression.

Mis-regulated epigenetic modifications in RNAs are associated with human cancers. The transfer RNAs (tRNAs) are the most heavily modified RNA species in cells; however, little is known about the functions of tRNA modifications in cancers. In this study, we uncovered that the expression levels of tRNA N7-methylguanosine (m7G) methyltransferase complex components methyltransferase-like 1 (METTL1) and WD repeat domain 4 (WDR4) are significantly elevated in human lung cancer samples and negatively associated with patient prognosis. Impaired m7G tRNA modification upon METTL1/WDR4 depletion resulted in decreased cell proliferation, colony formation, cell invasion, and impaired tumorigenic capacities of lung cancer cells in vitro and in vivo. Moreover, gain-of-function and mutagenesis experiments revealed that METTL1 promoted lung cancer growth and invasion through regulation of m7G tRNA modifications. Profiling of tRNA methylation and mRNA translation revealed that highly translated mRNAs have higher frequencies of m7G tRNA-decoded codons, and knockdown of METTL1 resulted in decreased translation of mRNAs with higher frequencies of m7G tRNA codons, suggesting that tRNA modifications and codon usage play an essential function in mRNA translation regulation. Our data uncovered novel insights on mRNA translation regulation through tRNA modifications and the corresponding mRNA codon compositions in lung cancer, providing a new molecular basis underlying lung cancer progression.

Evaluation of the prognostic value of paraoxonase 1 in the recurrence and metastasis of hepatocellular carcinoma and establishment of a liver-specific predictive model of survival.

BACKGROUND: Hepatocellular carcinoma is a malignant tumor with a highly invasive and metastatic phenotype, and the detection of potential indicators associated with its recurrence and metastasis after surgical resection is critical for patient survival. METHODS: Transcriptome data for large cohorts (n = 1432) from multicenter sources were comprehensively analyzed to explore such potential signatures. The prognostic value of the selected indicators was investigated and discussed, and a comparison with conventional clinicopathological features was performed. A survival predictive nomogram for 5-year survival was established with the selected indicator using the Cox proportional hazards regression. To validate the indicator at the protein level, we performed immunohistochemical staining with paraffin-embedded slides of hepatocellular carcinoma samples (n = 67 patients) from our hospital. Finally, a gene set enrichment analysis (GSEA) was performed to detect the underlying biological processes and internal mechanisms. RESULTS: The liver-specific protein paraoxonase 1 (PON1) was found to be the most relevant indicator of tumor recurrence, invasiveness, and metastasis in the present study, and the downregulation of PON1 might reveal poor survival for patients with hepatocellular carcinoma. The C-index of the PON1-related nomogram was 0.714, thus indicating a more effective predictive performance than the 7th American Joint Committee on Cancer (AJCC) tumor stage (0.534), AJCC T stage (0.565), or alpha-fetoprotein (0.488). The GSEA revealed that PON1 was associated with several hepatocellular carcinoma-related pathways, including the cell cycle, DNA replication, gap junction and p53 downstream pathways. CONCLUSIONS: The downregulation of paraoxonase 1 may suggest worse outcomes and a higher recurrence rate. Thus, paraoxonase 1 might represent an indicator for predicting the survival of patients with hepatocellular carcinoma.

miR-17-5p suppresses cell proliferation and invasion by targeting ETV1 in triple-negative breast cancer.

BACKGROUND: Triple-negative breast cancer (TNBC) is the malignancy with the worst outcome among all breast cancer subtypes. We reported that ETV1 is a significant oncogene in TNBC tumourigenesis. Consequently, investigating the critical regulatory microRNAs (miRNAs) of ETV1 may be beneficial for TNBC targeted therapy. METHODS: We performed in situ hybridization (ISH) and immunohistochemistry (IHC) to detect the location of miR-17-5p and ETV1 in TNBC patient samples, respectively. miR-17-5p expression in TNBC tissues and cell lines was assessed by quantitative real-time PCR (qRT-PCR). ETV1 expression was evaluated by qRT-PCR, western blotting and IHC. Cell Counting Kit-8 (CCK-8), colony formation, Transwell and wound closure assays were utilized to determine the TNBC cell proliferation and migration capabilities. In vivo tumour metastatic assays were performed in a zebra fish model. RESULTS: The abundance of miR-17-5p was significantly decreased in TNBC cell lines and clinical TNBC tissues. The miR-17-5p expression levels were closely correlated with tumour size (P < 0.05) and TNM stage (P < 0.05). By contrast, the expression of ETV1 was significantly up-regulated in TNBC cell lines and tissues. There is an inverse correlation between the expression status of miR-17-5p and ETV1 (r = -0.28, P = 3.88 × 10-3). Luciferase reporter assay confirmed that ETV1 was a direct target of miR-17-5p. Forced expression of miR-17-5p in MDA-MB-231 or BT549 cells significantly decreased ETV1 expression and suppressed cell proliferation, migration in vitro and tumour metastasis in vivo. However, rescuing the expression of ETV1 in the presence of miR-17-5p significantly recovered the cell phenotype. High miR-17-5p expression was associated with a significantly favourable prognosis, in either the ETV1-positive or ETV1-negative groups (log-rank test, P < 0.001; P < 0.001). Both univariate and multivariate analyses showed that miR-17-5p and ETV1 were independent risk factors in the prognosis of TNBC patient. CONCLUSIONS: Our data indicate that miR-17-5p acts as a tumour suppressor in TNBC by targeting ETV1, and a low-abundance of miR-17-5p may be involved in the pathogenesis of TNBC. These findings indicate that miR-17-5p may be a therapeutic target for TNBC.

PSCA acts as a tumor suppressor by facilitating the nuclear translocation of RB1CC1 in esophageal squamous cell carcinoma.

Esophageal squamous cell carcinoma (ESCC) is an aggressive malignancy; its mechanisms of development and progression are poorly understood. By high-throughput transcriptome sequencing (RNA-Seq) profiling of three pairs of primary ESCCs and their corresponding non-tumorous tissues, we identified that prostate stem cell antigen (PSCA), a gene that encodes a glycosylphosphatidylinositol-anchored protein, is significantly downregulated in ESCC. Here, we reported decreased expression of PSCA in 188/218 (86.2%) of primary ESCC cases and was negatively regulated by its transcription factor sex-determining region Y-box5 that was significantly associated with the poor differentiation (P = 0.003), increased lymph node metastasis (P < 0.0001), advanced stage (P = 0.007), and disease-specific survival (P < 0.0001), but not associated with the recently reported transcrible rs2294008 (C > T) polymorphism in ESCC. Functional studies showed that PSCA could arrest cell cycle progression and promote cell differentiation independent of the start codon polymorphism. Further mechanistic studies revealed that retinoblastoma 1-inducible coiled-coil 1 (RB1CC1), a key signaling node to regulate cellular proliferation and differentiation, interacted specifically with PSCA in ESCC cells. Binding of PSCA and RB1CC1 in cytoplasm resulted in stabilization and translocation of RB1CC1 into nucleus, thereby activating key factors involved in cell cycle arrest and differentiation. Collectively, our data provide a novel molecular mechanism for the tumor suppressor role of PSCA and may help design effective therapy targeting PSCA-RB1CC1 pathway to control esophageal cancer growth and differentiation.

CD133+ liver cancer stem cells resist interferon-gamma-induced autophagy.

BACKGROUND: Hepatocellular carcinoma (HCC) is one of the most fatal malignancies worldwide, and CD133 is a popular cancer stem cell (CSC) marker for HCC. CD133(+) CSCs have been reported to resist conventional chemo- and radiotherapy, but little is known about their response to immune surveillance. Interferon-gamma (IFN-γ) is one of key cytokines that the immune system produce to eradicate cancer cells, so we investigated the function of IFN-γ on CD133+ HCC CSCs in this study. METHODS: The response of CD133(+) cells to IFN-γ was performed with functional assays (cell proliferation assay and tumor formation in nude mice), flow cytometry, immunofluorescence staining and RNA interference. RESULTS: We found that IFN-γ inhibited the proliferation of cell lines with low percentage of CD133(+) cells (wild-type human cells, BEL7402, QGY7701) but it did not affect the proliferation of cell lines with high percentage of CD133(+) cells (wild-type human cells, Huh7, PLC8024) in vivo and in vitro (nude mice). Flow cytometry analysis demonstrated that the percentage of CD133+ cells increased after IFN-γ treatment of low CD133(+) cell lines. Furthermore, IFN-γ induced the autophagy of low CD133(+) cell lines to decrease proliferation. CONCLUSION: CD133(+) HCC CSCs resisted IFN-γ-induced autophagy, which might also be a mechanism through which CSCs resist immune eradication.

REGγ regulates ERα degradation via ubiquitin-proteasome pathway in breast cancer.

REGγ is a proteasome coactivator which regulates proteolytic activity in eukaryotic cells. Abundant lines of evidence have showed that REGγ is over expressed in a number of human carcinomas. However, its precise role in the pathogenesis of cancer is still unclear. In this study, by examining 200 human breast cancer specimens, we demonstrated that REGγ was highly expressed in breast cancers, and the expression of REGγ was positively correlated with breast cancer patient estrogen receptor alpha (ERα) status. Moreover, the expression of REGγ was found positively associated with poor clinical features and low survival rates in ERα positive breast cancer patients. Further cell culture studies using MCF7 and BT474 breast cancer cell lines showed that cell proliferation, motility, and invasion capacities were decreased significantly by REGγ knockdown. Lastly, we demonstrated that REGγ indirectly regulates the degradation of ERα protein via ubiquitin-proteasome pathway. In conclusion, our findings provide the evidence that REGγ expression was positively correlated with ERα status and poor clinical prognosis in ERα positive breast cancer patients. As well, we disclose a new connection between the two molecules that are both highly expressed in most breast cancer cases.

MicroRNA-129-5p inhibits hepatocellular carcinoma cell metastasis and invasion via targeting ETS1.

MiR-129-5p is deregulated in various human cancers and has been associated with hepatocellular carcinoma (HCC) progression. However, the underlying mechanisms of miR-129-5p involvement in the development and progression of HCC and the effects of miR-129-5p deregulation on the clinical characteristics observed in HCC patients remain poorly understood. We therefore investigated the correlation between low miR-129-5p expression and vascular invasion, intrahepatic metastasis, and poor patient survival. Ectopic restoration of miR-129-5p expression in HCC cells suppressed cellular migration and invasion and the expression of v-ets erythroblastosis virus E26 oncogene homolog 1 (ETS1), while inhibition of endogenous miR-129-5p caused an increase in these parameters. We identified the ETS1 gene as a novel direct target of miR-129-5p. SiRNA-mediated ETS1 knockdown rescued the effects of anti-miR-129-5p inhibitor in HCC cell lines, while the effects of miR-129-5p overexpression were partially phenocopied in the knockdown model. In addition, miR-129-5p levels inversely correlated with those of ETS1 in HCC cells and tissues. Taken together, our findings indicate an important role for miR-129-5p in the molecular etiology of invasive HCC and suggest that miR-129-5p could have potential therapeutic applications in HCC.

COP1, the negative regulator of ETV1, influences prognosis in triple-negative breast cancer.

BACKGROUND: ETS variant 1 (ETV1) and E3 ubiquitin ligase constitutive photomorphogenetic 1 (COP1) have been proposed to be a pair of oncogene and tumor suppressor. However, the co-existing status of ETV1 and COP1 in triple-negative breast cancer (TNBC) and their predictive role in determining the patient's outcome are uncertain. METHODS: We examined the abundance of COP1 and ETV1 proteins and their clinicopathologic significance in archival TNBC tissues from 105 patients by tissue microarray. The potential function link between COP1 and ETV1 was observed in MDA-MB-231 cells by cell proliferation, invasion and migration assays. RESULTS: ETV1 expression was higher in TNBC tissues compared to normal tissues, while COP1 was lower. ETV1 expression was negatively associated with COP1 abundance in TNBCs. Overexpression of COP1 led to significant reduction of ETV1 in MDA-MB-231 cells, and suppressed the cells migration and invasion. Rescue of ETV1 expression in the presence of COP1 notably regained the cells behaviors. ETV1-positive group was associated with a markedly poor overall survival. Meanwhile, we had observed favourable prognosis in COP1-positive cases for the first time. Multivariate analysis showed that COP1 together with ETV1 were independent risk factors in the prognosis of TNBC patients. CONCLUSIONS: COP1 might be a tumor suppressor by negative regulating ETV1 in patients with TNBCs. COP1 and ETV1 are a pair of independent predictors of prognosis for TNBC cases. Thus, targeting them might be a potential strategy for personalized TNBC treatment.

Aqp2-expressing cells give rise to renal intercalated cells.

The mammalian collecting duct comprises principal and intercalated cells, which maintain sodium/water and acid/base balance, respectively, but the epigenetic contributors to the differentiation of these cell types remain unknown. Here, we investigated whether the histone H3 K79 methyltransferase Dot1l, which is highly expressed in principal cells, participates in this process. Taking advantage of the distribution of aquaporin 2 (Aqp2), which localizes to principal cells of the collecting duct, we developed mice lacking Dot1l in Aqp2-expressing cells (Dot1l(AC)) and found that these mice had approximately 20% fewer principal cells and 13%-16% more intercalated cells than control mice. This deletion of Dot1l in principal cells abolished histone H3 K79 methylation in these cells, but unexpectedly, most intercalated cells also had undetectable di-methyl K79, suggesting that Aqp2(+) cells give rise to intercalated cells. These Aqp2(+) cell-derived intercalated cells were present in both developing and mature kidneys. Furthermore, compared with control mice, Dot1l(AC) mice had 40% higher urine volume and 18% lower urine osmolarity with relatively normal electrolyte and acid-base homeostasis. In conclusion, these data suggest that Dot1l deletion facilitates the differentiation of some α- and ß-intercalated cells from Aqp2-expressing progenitor cells or mature principal cells.

ATP6V0A1-dependent cholesterol absorption in colorectal cancer cells triggers immunosuppressive signaling to inactivate memory CD8+ T cells.

Obesity shapes anti-tumor immunity through lipid metabolism; however, the mechanisms underlying how colorectal cancer (CRC) cells utilize lipids to suppress anti-tumor immunity remain unclear. Here, we show that tumor cell-intrinsic ATP6V0A1 drives exogenous cholesterol-induced immunosuppression in CRC. ATP6V0A1 facilitates cholesterol absorption in CRC cells through RAB guanine nucleotide exchange factor 1 (RABGEF1)-dependent endosome maturation, leading to cholesterol accumulation within the endoplasmic reticulum and elevated production of 24-hydroxycholesterol (24-OHC). ATP6V0A1-induced 24-OHC upregulates TGF-ß1 by activating the liver X receptor (LXR) signaling. Subsequently, the release of TGF-ß1 into the tumor microenvironment by CRC cells activates the SMAD3 pathway in memory CD8+ T cells, ultimately suppressing their anti-tumor activities. Moreover, we identify daclatasvir, a clinically used anti-hepatitis C virus (HCV) drug, as an ATP6V0A1 inhibitor that can effectively enhance the memory CD8+ T cell activity and suppress tumor growth in CRC. These findings shed light on the potential for ATP6V0A1-targeted immunotherapy in CRC.

miR-338-3p suppresses invasion of liver cancer cell by targeting smoothened.

MicroRNAs are involved in human carcinogenesis and cancer progression. Our previous study has shown that loss of miR-338-3p expression is associated with clinical aggressiveness of hepatocellular carcinoma (HCC). However, the exact roles and mechanisms of miR-338-3p remain unknown in HCC. To determine whether and how miR-338-3p influences liver cancer cell invasion, we studied miR-338-3p in the liver cancer cell lines, and we found that miR-338-3p is down-regulated in treated cells. Forced expression of miR-338-3p in SK-HEP-1 cells suppressed cell migration and invasion, whereas inhibition of miR-338-3p in SMMC-7721 cells induced cell migration and invasion. Furthermore, smoothened (SMO) was identified as a direct target of miR-338-3p. Forced expression of miR-338-3p down-regulated SMO and matrix metalloproteinase (MMP)-9 expression, but inhibition of miR-338-3p up-regulated SMO and MMP9 expression. However, small interfering RNA targeted SMO reversed the effects induced by blockade of miR-338-3p. SMO and MMP9 were overexpressed and associated with invasion and metastasis in HCC tissues. These data indicate that miR-338-3p suppresses cell invasion by targeting the smoothened gene in liver cancer in vitro and miR-338-3p might be a novel potential strategy for liver cancer treatment.

LINC01194 recruits NUMA1 to promote ubiquitination of RYR2 to enhance malignant progression in triple-negative breast cancer.

Long intergenic nonprotein coding RNA 1194 (LINC01194) has been reported as an oncogene in several cancer types, but its expression and potential role in triple-negative breast cancer (TNBC) are still unclear. We found that LINC01194 was significantly highly expressed in TNBC based on The Cancer Genome Atlas (TCGA) database. Data from in vitro experiments and in vivo assays demonstrated that LINC01194 promoted TNBC progression. Through bioinformatics prediction, mass spectrometry, and mechanical experiments, we found that LINC01194 could recruit nuclear mitotic apparatus protein 1 (NUMA1) to bind to the untranslated region (3'UTR) of ubiquitin-conjugating enzyme E2 C (UBE2C) 3' and stabilize UBE2C mRNA. Moreover, we found that UBE2C acted as an ubiquitin ligase to promote the ubiquitination and degradation of ryanodine receptor type 2 (RYR2) that inhibited the progression of TNBC by inhibiting the Wnt/ß-catenin signaling pathway. In summary, LINC01194 activate the Wnt/ß-catenin signaling pathway and accelerates the malignant progression of TNBC by recruiting NUMA1 to stabilize UBE2C mRNA and thus promotes RYR2 ubiquitination and degradation. These findings might provide a more effective therapeutic strategy for TNBC patients.

KIF17 maintains the epithelial phenotype of breast cancer cells and curbs tumour metastasis.

Kinesin superfamily motor protein 17 (KIF17) was previously identified downregulated in breast cancer and correlated with patient prognosis. However, its pathophysiological role in tumours remains unknown. Here, we confirmed that KIF17 was significantly under-expressed in breast cancer tissues and low KIF17 expression correlated with poor outcomes in patients with breast cancer. In vitro and in vivo experiments demonstrated that KIF17 overexpression in breast cancer cell lines significantly inhibited breast cancer invasion and metastasis. By establishing the lung metastatic MDA-MB-231 cell lines, we found a transient silence of KIF17 during the initiation of breast cancer metastasis. Further experiments revealed that KIF17 might suppress metastasis by regulating the level of acetylated tubulin to maintain cytoskeleton stability. Eventually, we found that the low expression of KIF17 in breast cancer is regulated by DNMT1-mediated 5-mC DNA methylation and epigenetic silencing. Decitabine can effectively improve the expression level of KIF17 in breast cancer cells. Our study demonstrates that KIF17 mediates microtubule acetylation to maintain the stability of microtubules, thereby inhibiting tumour invasion and metastasis.

Clinical significance of miR-221 and its inverse correlation with p27Kip¹ in hepatocellular carcinoma.

The aim of the present study is to explore possible role of miR-221 in the pathogenesis of HCC. Matched HCC and adjacent non-cancerous samples were assayed for the expression of miR-221 and three G1/S transition inhibitors: p27(Kip1), p21(WAF1/Cip1)and TGF-ß1 by in situ hybridization and immunohistochemistry respectively. p27(Kip1) is one of miR-221's proven targets. Real time qRT-PCR was used to investigate miR-221 and p27(Kip1) transcripts in different clinical stages. Western blotting was used to analyze the expression levels of p27(Kip1) protein in different clinical stages. In result, miR-221 and TGF-ß1 are frequently up-regulated in HCC, while p27(Kip1) and p21(WAF1/Cip1) proteins are frequently down-regulated. Moreover, miR-221 and p27(Kip1)'s expression correlated with metastasis and miR-221's expression also correlated with tumor size. Both of p21(WAF1/Cip1)and TGF-ß1's expression correlated with tumor differentiations. miR-221's upregulation and p27(Kip1)'s downregulation were significantly associated with tumor stages and metastasis. In conclusion, miR-221 is important in tumorigenesis of HCC, possibly by specifically down-regulating p27(Kip1), a cell-cycle inhibitor. These results indicate miR-221 as a new therapeutic target in HCC.

ZIPK activates the IL-6/STAT3 signaling pathway and promotes cisplatin resistance in gastric cancer cells.

Gastric cancer is one of the most common malignant cancers globally. Chemotherapy resistance remains a major obstacle in the treatment of gastric cancer, and the molecular mechanisms underlying drug resistance are still not well understood. We previously reported that Zipper interacting protein kinase (ZIPK), also known as death-associated protein kinase3, exerts an oncogenic effect on gastric cancer via activation of Akt/NF-κB signaling and promotion of stemness. Here, we explored the roles of ZIPK in cisplatin resistance. We report that ZIPK enhances cell proliferation and invasion and reduces the antitumor activity of cisplatin in gastric cancer. In addition, our western blot data suggest that ZIPK activated the IL-6/STAT3 signaling pathway. Furthermore, ZIPK increased the expression of IL-6 and multidrug-resistance genes. Using the STAT3 inhibitor stattic to block the IL-6/STAT3 signaling pathway strongly increased the sensitivity of ZIPK-expressed cells to cisplatin. In conclusion, ZIPK may play a role in cisplatin resistance through activation of the IL-6/ STAT3 signaling pathway. Inhibition of STAT3 in gastric cancer overexpressing ZIPK might have potential to improve the efficacy of cisplatin.

LncRNA LGALS8-AS1 Promotes Breast Cancer Metastasis Through miR-125b-5p/SOX12 Feedback Regulatory Network.

BACKGROUND: Metastasis is a major factor weakening the long-term survival of breast cancer patients. Increasing evidence revealed that long non-coding RNAs (lncRNAs) were involved in the occurrence and development of breast cancer. In this study, we aimed to investigate the role of LGALS8-AS1 in the metastatic progression of breast cancer cells and its potential mechanisms. RESULTS: The lncRNA LGALS8-AS1 was highly expressed in breast cancer and associated with poor survival. LGALS8-AS1 functioned as an oncogenic lncRNA that promoted the metastasis of breast cancer both in vitro and in vivo. It upregulated SOX12 via competing as a competing endogenous RNA (ceRNA) for sponging miR-125b-5p and acted on the PI3K/AKT signaling pathway to promote the metastasis of breast cancer. Furthermore, SOX12, in turn, activated LGALS8-AS1 expression via direct recognition of its sequence binding enrichment motif on the LGALS8-AS1 promoter, thereby forming a positive feedback regulatory loop. CONCLUSION: This study manifested a novel mechanism of LGALS8-AS1 facilitating the metastasis of breast cancer. The LGALS8-AS1/miR-125b-5p/SOX12 reciprocal regulatory loop dyscrasia promoted the migration and invasion of breast cancer cells. This signaling axis could be applicable to the design of novel therapeutic strategies against this malignancy.

DAPK3 inhibits gastric cancer progression via activation of ULK1-dependent autophagy.

Dysregulation of the balance between cell proliferation and cell death is a central feature of malignances. Death-associated protein kinase 3 (DAPK3) regulates programmed cell death including apoptosis and autophagy. Our previous study showed that DAPK3 downregulation was detected in more than half of gastric cancers (GCs), which was related to tumor invasion, metastasis, and poor prognosis. However, the precise molecular mechanism underlying DAPK3-mediated tumor suppression remains unclear. Here, we showed that the tumor suppressive function of DAPK3 was dependent on autophagy process. Mass spectrometry, in vitro kinase assay, and immunoprecipitation revealed that DAPK3 increased ULK1 activity by direct ULK1 phosphorylation at Ser556. ULK1 phosphorylation by DAPK3 facilitates the ULK1 complex formation, the VPS34 complex activation, and autophagy induction upon starvation. The kinase activity of DAPK3 and ULK1 Ser556 phosphorylation were required for DAPK3-modulated tumor suppression. The coordinate expression of DAPK3 with ULK1 Ser556 phosphorylation was confirmed in clinical GC samples, and this co-expression was correlated with favorable survival outcomes in patients. Collectively, these findings indicate that the tumor-suppressor roles of DAPK3 in GC are associated with autophagy and that DAPK3 is a novel autophagy regulator, which can directly phosphorylate ULK1 and activate ULK1. Thus, DAPK3 might be a promising prognostic autophagy-associated marker.

Patient-Derived Organoids Can Guide Personalized-Therapies for Patients with Advanced Breast Cancer.

Most breast cancers at an advanced stage exhibit an aggressive nature, and there is a lack of effective anticancer options. Herein, the development of patient-derived organoids (PDOs) is described as a real-time platform to explore the feasibility of tailored treatment for refractory breast cancers. PDOs are successfully generated from breast cancer tissues, including heavily treated specimens. The microtubule-targeting drug-sensitive response signatures of PDOs predict improved distant relapse-free survival for invasive breast cancers treated with adjuvant chemotherapy. It is further demonstrated that PDO pharmaco-phenotyping reflects the previous treatment responses of the corresponding patients. Finally, as clinical case studies, all patients who receive at least one drug predicate to be sensitive by PDOs achieve good responses. Altogether, the PDO model is developed as an effective platform for evaluating patient-specific drug sensitivity in vitro, which can guide personal treatment decisions for breast cancer patients at terminal stage.

Low expression of CDK12 in gastric cancer is correlated with advanced stage and poor outcome.

BACKGROUND: Cyclin-dependent kinase 12 (CDK12) belongs to the cyclin-dependent kinase (CDK) family, modulating multiple cellular functions including DNA damage response (DDR), development and cellular differentiation, transcription, mRNA processing, splicing and pre-mRNA processing. CDK12 has been reported as both tumor suppressor and oncogene in various kinds of tumor. The function of CDK12 in gastric cancer (GC) remains unclear. METHODS/RESULTS: CDK12 mRNA expression was decreased in GC compared with non-tumor tissue based on GEO database. Also, low mRNA expression of CDK12 was detected in GC cell lines by qPCR. Similarly, CDK12 protein expression was also reduced in GC tissues compared with adjacent non-tumor tissues in 177 GC patients as shown by immunohistochemistry. Low expression of CDK12 was associated with organ metastasis, poorly differentiated adenocarcinoma and advanced stage. Consistent with human protein atlas database analysis, Low expression of CDK12 was correlated with worse overall survival (P < 0.001). Multivariate Cox regression indicated that low expression of CDK12 was an independent prognostic factor for GC patients (P < 0.001). Finally, a gene set enrichment analysis was performed to detect underlying internal mechanisms and biological processes. CONCLUSIONS: CDK12 is down-regulated in GC and its expression is negatively correlated with advanced stage, poorly differentiated adenocarcinoma and poor outcomes. Our findings suggest that CDK12 may be a potential tumor suppressor in GC.