Peptidase inhibitor (PI16) impairs bladder cancer metastasis by inhibiting NF-κB activation via disrupting multiple-site ubiquitination of NEMO.

BACKGROUND: Bladder cancer (BLCA) is a malignancy that frequently metastasizes and leads to poor patient prognosis. It is essential to understand the molecular mechanisms underlying the progression and metastasis of BLCA and identify potential biomarkers. METHODS: The expression of peptidase inhibitor 16 (PI16) was analysed using quantitative PCR, immunoblotting and immunohistochemistry assays. The functional roles of PI16 were evaluated using wound healing, transwell, and human umbilical vein endothelial cell tube formation assays, as well as in vivo tumour models. The effects of PI16 on nuclear factor κB (NF-κB) signalling activation were examined using luciferase reporter gene systems, immunoblotting and immunofluorescence assays. Co-immunoprecipitation was used to investigate the interaction of PI16 with annexin-A1 (ANXA1) and NEMO. RESULTS: PI16 expression was downregulated in bladder cancer tissues, and lower PI16 levels correlated with disease progression and poor survival in patients with BLCA. Overexpressing PI16 inhibited BLCA cell growth, motility, invasion and angiogenesis in vitro and in vivo, while silencing PI16 had the opposite effects. Mechanistically, PI16 inhibited the activation of the NF-κB pathway by interacting with ANXA1, which inhibited K63 and M1 ubiquitination of NEMO. CONCLUSIONS: These results indicate that PI16 functions as a tumour suppressor in BLCA by inhibiting tumour growth and metastasis. Additionally, PI16 may serve as a potential biomarker for metastatic BLCA.

Extracellular vesicles-transferred SBSN drives glioma aggressiveness by activating NF-κB via ANXA1-dependent ubiquitination of NEMO.

Glioma is the most common malignant primary brain tumor with aggressiveness and poor prognosis. Although extracellular vesicles (EVs)-based cell-to-cell communication mediates glioma progression, the key molecular mediators of this process are still not fully understood. Herein, we elucidated an EVs-mediated transfer of suprabasin (SBSN), leading to the aggressiveness and progression of glioma. High levels of SBSN were positively correlated with clinical grade, predicting poor clinical prognosis of patients. Upregulation of SBSN promoted, while silencing of SBSN suppressed tumorigenesis and aggressiveness of glioma cells in vivo. EVs-mediated transfer of SBSN resulted in an increase in SBSN levels, which promoted the aggressiveness of glioma cells by enhancing migration, invasion, and angiogenesis of recipient glioma cells. Mechanistically, SBSN activated NF-κB signaling by interacting with annexin A1, which further induced Lys63-linked and Met1-linear polyubiquitination of NF-κB essential modulator (NEMO). In conclusion, the communication of SBSN-containing EVs within glioma cells drives the formation and development of tumors by activating NF-κB pathway, which may provide potential therapeutic target for clinical intervention in glioma.

SBSN drives bladder cancer metastasis via EGFR/SRC/STAT3 signalling.

BACKGROUND: Patients with metastatic bladder cancer have very poor prognosis and predictive biomarkers are urgently needed for early clinical detection and intervention. In this study, we evaluate the effect and mechanism of Suprabasin (SBSN) on bladder cancer metastasis. METHODS: A tissue array was used to detect SBSN expression by immunohistochemistry. A tumour-bearing mouse model was used for metastasis evaluation in vivo. Transwell and wound-healing assays were used for in vitro evaluation of migration and invasion. Comprehensive molecular screening was achieved by western blotting, immunofluorescence, luciferase reporter assay, and ELISA. RESULTS: SBSN was found markedly overexpressed in bladder cancer, and indicated poor prognosis of patients. SBSN promoted invasion and metastasis of bladder cancer cells both in vivo and in vitro. The secreted SBSN exhibited identical biological function and regulation in bladder cancer metastasis, and the interaction of secreted SBSN and EGFR could play an essential role in activating the signalling in which SBSN enhanced the phosphorylation of EGFR and SRC kinase, followed with phosphorylation and nuclear location of STAT3. CONCLUSIONS: Our findings highlight that SBSN, and secreted SBSN, promote bladder cancer metastasis through activation of EGFR/SRC/STAT3 pathway and identify SBSN as a potential diagnostic and therapeutic target for bladder cancer.

Fis1 phosphorylation by Met promotes mitochondrial fission and hepatocellular carcinoma metastasis.

Met tyrosine kinase, a receptor for a hepatocyte growth factor (HGF), plays a critical role in tumor growth, metastasis, and drug resistance. Mitochondria are highly dynamic and undergo fission and fusion to maintain a functional mitochondrial network. Dysregulated mitochondrial dynamics are responsible for the progression and metastasis of many cancers. Here, using structured illumination microscopy (SIM) and high spatial and temporal resolution live cell imaging, we identified mitochondrial trafficking of receptor tyrosine kinase Met. The contacts between activated Met kinase and mitochondria formed dramatically, and an intact HGF/Met axis was necessary for dysregulated mitochondrial fission and cancer cell movements. Mechanically, we found that Met directly phosphorylated outer mitochondrial membrane protein Fis1 at Tyr38 (Fis1 pY38). Fis1 pY38 promoted mitochondrial fission by recruiting the mitochondrial fission GTPase dynamin-related protein-1 (Drp1) to mitochondria. Fragmented mitochondria fueled actin filament remodeling and lamellipodia or invadopodia formation to facilitate cell metastasis in hepatocellular carcinoma (HCC) cells both in vitro and in vivo. These findings reveal a novel and noncanonical pathway of Met receptor tyrosine kinase in the regulation of mitochondrial activities, which may provide a therapeutic target for metastatic HCC.

FUT8-mediated aberrant N-glycosylation of B7H3 suppresses the immune response in triple-negative breast cancer.

Most patients with triple negative breast cancer (TNBC) do not respond to anti-PD1/PDL1 immunotherapy, indicating the necessity to explore immune checkpoint targets. B7H3 is a highly glycosylated protein. However, the mechanisms of B7H3 glycosylation regulation and whether the sugar moiety contributes to immunosuppression are unclear. Here, we identify aberrant B7H3 glycosylation and show that N-glycosylation of B7H3 at NXT motif sites is responsible for its protein stability and immunosuppression in TNBC tumors. The fucosyltransferase FUT8 catalyzes B7H3 core fucosylation at N-glycans to maintain its high expression. Knockdown of FUT8 rescues glycosylated B7H3-mediated immunosuppressive function in TNBC cells. Abnormal B7H3 glycosylation mediated by FUT8 overexpression can be physiologically important and clinically relevant in patients with TNBC. Notably, the combination of core fucosylation inhibitor 2F-Fuc and anti-PDL1 results in enhanced therapeutic efficacy in B7H3-positive TNBC tumors. These findings suggest that targeting the FUT8-B7H3 axis might be a promising strategy for improving anti-tumor immune responses in patients with TNBC.

Clinical Evidence for Locoregional Surgery of the Primary Tumor in Patients with De Novo Stage IV Breast Cancer.

BACKGROUND: Whether primary tumor surgery is better than no surgery in patients with de novo stage IV breast cancer remains controversial. METHODS: This study combined prospective clinical trials and a multicenter cohort to evaluate the impact of locoregional surgery in de novo stage IV breast cancer. The GRADE approach was used to assess the quality of evidence in meta-analysis, and propensity score matching analysis was used in the cohort study. This study was registered with PROSPERO CRD42016043766 and ClinicalTrials.gov NCT04456855. RESULTS: A total of 1110 patients from six trials and 353 patients from the cohort study were included. The meta-analysis showed that compared with no surgery, locoregional surgery did not prolong overall survival (hazard ratio [HR] = 0.90, P = 0.40; moderate-quality) but had a significantly longer locoregional progression-free survival (HR = 0.23, P < 0.001; moderate-quality). The subgroup analysis of solitary bone-only metastasis (HR = 0.47, P = 0.04; high-quality) resulted in prolonged overall survival. In the cohort study, locoregional surgery showed a survival benefit (HR = 0.63, P = 0.041) before matching, but not (HR = 0.84, P = 0.579) after matching. Patients with bone-only metastasis showed a survival advantage in surgery compared with no surgery before matching (HR = 0.36, P = 0.034) as well as after matching (HR = 0.18, P = 0.017). CONCLUSIONS: This study indicated that locoregional surgery had a significantly longer locoregional progression-free survival than no surgery in de novo stage IV breast cancer, and patients with bone-only metastasis tended to show an overall survival benefit from surgery.

Disruption of super-enhancer-driven tumor suppressor gene RCAN1.4 expression promotes the malignancy of breast carcinoma.

BACKGROUND: Super-enhancers (SEs) play a crucial role in cancer, which is often associate with activated oncogenes. However, little is known about how SEs facilitate tumour suppression. Individuals with Down syndrome exhibit a remarkably reduced incidence of breast cancer (BC), moving the search for tumor suppressor genes on human chromosome 21 (HSA21). In this study, we aim to identify and explore potential mechanisms by which SEs are established for tumor suppressor RCAN1.4 on HSA21 in BC. METHODS: In silico analysis and immunohistochemical staining were used to assess the expression and clinical relevance of RCAN1.4 and RUNX3 in BC. Function experiments were performed to evaluate the effects of RCAN1.4 on the malignancy of breast carcinoma in vitro and in vivo. ChIP-seq data analysis, ChIP-qPCR, double-CRISPR genome editing, and luciferase reporter assay were utilized to confirm RUNX3 was involved in regulating RCAN1.4-associated SE in BC. The clinical value of co-expression of RCAN1.4 and RUNX3 was evaluated in BC patients. RESULTS: Here, we characterized RCAN1.4 as a potential tumour suppressor in BC. RCAN1.4 loss promoted tumour metastasis to bone and brain, and its overexpression inhibited tumour growth by blocking the calcineurin-NFATc1 pathway. Unexpectedly, we found RCAN1.4 expression was driven by a ~ 23 kb-long SE. RCAN1.4-SEdistal was sensitive to BRD4 inhibition, and its deletion decreased RCAN1.4 expression by over 90% and induced the malignant phenotype of BC cells. We also discovered that the binding sites in the SE region of RCAN1.4 were enriched for consensus sequences of transcription factor RUNX3. Knockdown of RUNX3 repressed the luciferase activity and also decreased H3K27ac enrichment binding at the SE region of RCAN1.4. Furthermore, abnormal SE-driven RCAN1.4 expression mediated by RUNX3 loss could be physiologically significant and clinically relevant in BC patients. Notably, we established a prognostic model based on RCAN1.4 and RUNX3 co-expression that effectively predicted the overall survival in BC patients. CONCLUSIONS: These findings reveal an important role of SEs in facilitating tumour suppression in BC. Considering that the combination of low RCAN1.4 and low RUNX3 expression has worse prognosis, RUNX3-RCAN1.4 axis maybe a novel prognostic biomarker and therapeutic target for BC patients.

Autophagy deficiency promotes triple-negative breast cancer resistance to T cell-mediated cytotoxicity by blocking tenascin-C degradation.

Most triple-negative breast cancer (TNBC) patients fail to respond to T cell-mediated immunotherapies. Unfortunately, the molecular determinants are still poorly understood. Breast cancer is the disease genetically linked to a deficiency in autophagy. Here, we show that autophagy defects in TNBC cells inhibit T cell-mediated tumour killing in vitro and in vivo. Mechanistically, we identify Tenascin-C as a candidate for autophagy deficiency-mediated immunosuppression, in which Tenascin-C is Lys63-ubiquitinated by Skp2, particularly at Lys942 and Lys1882, thus promoting its recognition by p62 and leading to its selective autophagic degradation. High Tenascin-C expression is associated with poor prognosis and inversely correlated with LC3B expression and CD8+ T cells in TNBC patients. More importantly, inhibition of Tenascin-C in autophagy-impaired TNBC cells sensitizes T cell-mediated tumour killing and improves antitumour effects of single anti-PD1/PDL1 therapy. Our results provide a potential strategy for targeting TNBC with the combination of Tenascin-C blockade and immune checkpoint inhibitors.

Polo-Like Kinase 1 phosphorylates and stabilizes KLF4 to promote tumorigenesis in nasopharyngeal carcinoma.

Rationale: Advanced nasopharyngeal carcinoma (NPC) is an aggressive disease with no targeted therapies and poor outcomes. New innovative targets are urgently needed. KLF4 has been extensively studied in the context of tumors, and current data suggest that it can act as either a tissue-specific tumor-inhibiting or a tumor-promoting gene. Here, we found that KLF4 played as a tumor-promoting gene in NPC, and could be mediated by PLK1. Methods: Tissue immunohistochemistry (IHC) assay was performed to identify the role of KLF4 in NPC. Global gene expression experiments were performed to explore the molecular mechanisms underlying KLF4-dependent tumorigenesis. Small-molecule kinase inhibitor screening was performed to identify potential upstream kinases of KLF4. The pharmacologic activity of polo-like kinase inhibitor volasertib (BI6727) in vitro and in vivo was determined. Result: Our investigation showed that high expression of KLF4 was correlated with poor prognosis in NPC. Moreover, genome-wide profiling revealed that KLF4 directly activated oncogenic programmes, including gene sets associated with KRAS, VEGF, and MYC signalling. We further found that inhibition of polo-like kinase 1 could downregulate the expression of KLF4 and that PLK1 directly phosphorylated KLF4 at Ser234. Notably, phosphorylation of KLF4 by PLK1 caused the recruitment and binding of the E3 ligase TRAF6, which resulted in KLF4 K32 K63-linked ubiquitination and stabilization. Moreover, KLF4 could enhance TRAF6 expression at the transcriptional level, thus initiating a KLF4-TRAF6 feed-forward loop. Treatment with the PLK1 inhibitor volasertib (BI6727) significantly inhibited tumor growth in nude mice. Conclusion: Our study unveiled a new PLK1-TRAF6-KLF4 feed-forward loop. The resulting increase in KLF4 ubiquitination leads to stabilization and upregulation of KLF4, which leads to tumorigenesis in NPC. These results expand our understanding of the role of KLF4 in NPC and validate PLK1 inhibitors as potential therapeutic agents for NPC, especially cancer patients with KLF4 overexpression.

Pedicled descending branch latissimus dorsi mini-flap in repairing partial mastectomy defect: Shoulder functional and esthetic outcomes.

BACKGROUND: The axillary-approach pedicled descending branch latissimus dorsi (LD) mini-flap presents clear benefits in repairing partial mastectomy defects. This study assessed the functional and esthetic outcomes of this flap compared with conventional breast-conserving surgery (BCS). METHODS: From October of 2015 to March of 2017, patients with early breast cancer were enrolled and assigned to the LD group or conventional BCS (CCS) group according to the need of using the pedicled descending branch LD mini-flap for volume replacement. Muscle strength and range of motion (ROMs) of bilateral shoulders, a disabilities of the arm, shoulder and hand (DASH) questionnaire, and an esthetic evaluation were conducted in all patients at 1 year after surgery. RESULTS: Thirty-two patients were assigned in the LD group, and 28 in the CCS group. There was no significant difference in muscle strength, ROMs of the shoulder or DASH scores between LD and CCS groups. The results of esthetic survey also revealed a similarly high level of esthetics in both groups. Donor-site seroma occurred in three patients in the LD group, and no other complication was observed. CONCLUSIONS: The pedicled descending branch LD mini-flap enabled larger excision with favorable esthetics, minimal functional impairment, low rate of complications, and high level of satisfaction.

Regorafenib Promotes Antitumor Immunity via Inhibiting PD-L1 and IDO1 Expression in Melanoma.

PURPOSE: Immune checkpoint blockade (ICB) therapy induces durable tumor regressions in a minority of patients with cancer. In this study, we aimed to identify kinase inhibitors that were capable of increasing the antimelanoma immunity. EXPERIMENTAL DESIGN: Flow cytometry-based screening was performed to identify kinase inhibitors that can block the IFNγ-induced PD-L1 expression in melanoma cells. The pharmacologic activities of regorafenib alone or in combination with immunotherapy in vitro and in vivo were determined. The mechanisms of regorafenib were explored and analyzed in melanoma patients treated with or without anti-PD-1 using The Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) datasets. RESULTS: Through screening of a kinase inhibitor library, we found approximately 20 agents that caused more than half reduction of cell surface PD-L1 level, and regorafenib was one of the most potent agents. Furthermore, our results showed that regorafenib, in vitro and in vivo, strongly promoted the antitumor efficacy when combined with IFNγ or ICB. By targeting the RET-Src axis, regorafenib potently inhibited JAK1/2-STAT1 and MAPK signaling and subsequently attenuated the IFNγ-induced PD-L1 and IDO1 expression without affecting MHC-I expression much. Moreover, RET and Src co-high expression was an independent unfavorable prognosis factor in melanoma patients with or without ICB through inhibiting the antitumor immune response. CONCLUSIONS: Our data unveiled a new mechanism of alleviating IFNγ-induced PD-L1 and IDO1 expression and provided a rationale to explore a novel combination of ICB with regorafenib clinically, especially in melanoma with RET/Src axis activation.

Pedicled Descending Branch Latissimus Dorsi Mini-flap for Repairing Partial Mastectomy Defect: A New Technique.

Volume loss is 1 of the major factors influencing cosmetic outcomes of breast after partial mastectomy (PM), especially for smaller breasts, and therefore, volume replacement is critical for optimizing the final aesthetic outcome. We present a novel technique of raising a pedicled descending branch latissimus dorsi (LD) mini-flap for reconstruction of PM defects via an axillary incision. After PM, the LD mini-flap is harvested through the existing axillary incision of the axillary dissection or the sentinel lymph node biopsy. The descending branches of thoracodorsal vessels and nerve are carefully identified and isolated. The transverse branches are protected to maintain muscle innervation and function. The LD muscle is then undermined posteriorly and inferiorly to create a submuscular pocket and a subcutaneous pocket between LD muscle and superficial fascia. Once the submuscular plane is created, the muscle is divided along the muscle fibers from the deep surface including a layer of fat above the muscle. Finally, the LD mini-flap is transferred to the breast defect. Given the limited length and mobility of the LD mini-flap, this approach is best utilized for lateral breast defects. However, for medial defects, the lateral breast tissue is rearranged to reconstruct the medial breast defect, and an LD mini-flap is then used to reconstruct the lateral breast donor site. This technique can therefore be employed to reconstruct all quadrants of the breast and can provide aesthetic outcomes without scars on the back, with minimal dysfunction of LD muscle.

Development and validation of a brief diabetic foot ulceration risk checklist among diabetic patients: a multicenter longitudinal study in China.

The study aims to develop and assess and validate a brief diabetic foot ulceration risk checklist among diabetic patients through a longitudinal study. Patients who had diabetes mellitus and had no foot ulceration and severe systematic disorders were recruited from eleven tertiary hospitals in nine provinces or municipalities of China. Internal consistency reliability, construct validity, concurrent validity, item property, and measurement invariance of the tool were assessed. The predictive capability of the tool was validated by the follow-up data using the receiver operating characteristic curve. At baseline, 477 valid cases were collected. Twelve items were remained after initial selection. Cronbach's alpha was 0.56. Confirmatory factor analysis showed that the model had acceptable goodness-of-fit yet local dependency between two items. Item response theory showed that most items had acceptable discrimination and difficulty parameters. Differential item functioning showed that tool had measurement invariance. 278 were followed up one year after the baseline. Follow-up showed that one-year incidence of ulceration among the patients was 3.6%, and the area under the receiver operating characteristic curve was 0.77 (95% confidence interval: 0.61-0.93). The cut-off point of the tool was 4, when sensitivity and specificity were 0.62 and 0.75 respectively. The checklist has good psychometric properties according to mixed evidences from classical and modern test theory, and has good predictive capability.