Landscape of DNA damage response gene alterations in breast cancer: A comprehensive investigation.

BACKGROUND: DNA damage response (DDR) gene alterations are prevalent in breast cancer (BC) and important for treatment decisions. Intensive studies on DDR alterations in BC are still needed. METHODS: The authors included 438 patients with metastatic breast cancer from their next-generation sequencing database and 1091 patients with early-stage breast cancer from The Cancer Genome Atlas (TCGA) database in the analysis to characterize molecular alterations in the DDR pathway. RESULTS: Germline DDR mutations were more prevalent in younger patients and those with HER2-negative cancers. Tumors with germline DDR mutations more commonly had somatic DDR mutations, especially those with germline Fanconi anemia (FA) pathway mutations. Notably, 66.67% (four of six) of patients with germline PALB2 mutations had tumors that harbored somatic PALB2 mutations. No differences in prognosis were observed in patients with germline or tumor somatic DDR mutations compared to patients and tumors that were wild-type. Compared to early BC, the frequency of somatic DDR mutations in metastatic cancers was significantly higher (24.89% vs. 16.02%, p < .001). Higher tumor mutation burdens were observed in cancers with somatic DDR mutations, but not in cancers with germline DDR mutations. Furthermore, tumors with somatic DDR mutations showed an abundance of anticancer immunological phenotypes. Somatic FA and mismatch repair pathway mutations were associated with increased expression of immune checkpoint molecules. Although most DDR genes were significantly positively associated with expression of proliferation-related genes, PARP3 expression was negatively correlated with MKI67 expression. Lower PARP3 expression was associated with a worse prognosis in TCGA database by multivariate Cox analysis. CONCLUSIONS: Patients with germline FA mutations more frequently have tumors with somatic DDR mutations. Somatic DDR mutations lead to anticancer immunological phenotypes in BC. No differences in prognosis according to germline or somatic DDR mutations were found.

Analysis of clinical features, genomic landscapes and survival outcomes in HER2-low breast cancer.

BACKGROUND: Novel human epidermal growth factor receptor 2 (HER2)-directed antibody-drug conjugates prompt the identification of the HER2-low subtype. However, the biological significance of HER2-low expression in breast cancer is unclear. METHODS: Clinical and genomic data of 579 metastatic breast cancer patients were reviewed from our next-generation sequencing (NGS) database and genomic analysis of early breast cancer patients from TCGA was also analyzed. FINDINGS: First, the clinicopathological characteristics of HER2-low patients were profoundly influenced by HR status and no difference of prognosis was observed between HER2-low and HER2-zero patients when paired by HR status, but notably HER2-low patients showed similar metastatic patterns to HER2-positive patients in the HR-positive (HR+ ) subgroup, with more brain and initial lung metastases and more cases of de novo stage IV breast cancer than HER2-zero patients. Second, among patients with primary HER2-low or HER2-zero tumors, the discordance of HER2 status between primary and metastatic tumors was significant, with 48.4% of patients with HER2-zero primary tumors exhibiting HER2-low phenotype in metastatic tumors in the HR+ subgroup. Third, within HR+ and HR-negative subtypes, HER2-low and HER2-zero tumors showed no substantial differences in mutation alterations and copy number variations. Forth, germline BRCA2 mutations were observed only in HER2-low patients in our NGS database, especially in HR+ HER2-low tumors. Finally, three molecular subtypes based on genomic alterations in HER2-low breast cancer were identified, which provided novel insights into heterogeneity in HER2-low breast cancer. CONCLUSIONS: After correcting for HR expression, only marginal differences in clinical and molecular phenotypes were determined between HER2-low and HER2-zero breast cancer. Therefore, HER2-low breast cancer is insufficient to be defined as a distinct molecular entity, but rather a heterogenous disease.

Exosomal MMP-1 transfers metastasis potential in triple-negative breast cancer through PAR1-mediated EMT.

PURPOSE: Triple-negative breast cancer (TNBC) is a subtype of breast cancer with high risk of distant metastasis, in which the intercellular communication between tumor cells also plays a role. Exosomes can be released by tumor cells and promote distant metastasis through intercellular communication or changes in tumor microenvironment, it is an optimized transportation facility for biologically active payloads. This was a hypothesis-generating research on role of exosomal payload in TNBC distant metastasis. METHODS: Exosomes isolated from supernatant of MDA-MB-231 and MDA-MB-231-HM (a highly pulmonary metastatic variant of parental MDA-MB-231 cells) were characterized. MMP-1 level was detected using mass spectrometry and western blot. Transwell assay, wound healing and CCK-8 assay were employed to explore the effect of exosomal MMP-1 on the metastatic capability of TNBC cells in vitro. Human breast cancer lung metastasis model in nude mice was established to observe the effect of exosomal MMP-1 in vivo. Tissue microarray and blood samples of TNBC patients were applied to analyze the relevance between MMP-1 with metastasis. RESULTS: MDA-MB-231-HM cells secrete exosomes enriched MMP-1, which can be taken up and enhance invasion and migration activities of TNBC cells, including MDA-MB-231, MDA-MB-468 and BT549. After ingesting exosomes enriched with MMP-1, cells secret more MMP-1, which may interact with membrane G protein receptor protease activated receptor 1 (PAR1), thereby initiating epithelial-mesenchymal transition (EMT) to enhance capability of migration and invasion. The lung colonization model shows that the expressions of MMP-1 and PAR1 in the metastases of the 231-HM-exo treated mice were both upregulated. Clinically, the enrichment of MMP-1 can be detected in exosomes extracted from serum of patients with metastasis at higher concentration than that in pre-operative patients. Moreover, in patients with multiple distant metastases, the level of MMP-1 in exosomes is also higher than that in patients with single lesion. CONCLUSION: MMP-1 from TNBC cells of high metastasis potential can promote the distant metastasis of transform those with low metastasis potential through PAR1-mediated EMT and is likely to be a potential molecular marker.

Efficacy and safety of mitoxantrone hydrochloride liposome injection in Chinese patients with advanced breast cancer: a randomized, open-label, active-controlled, single-center, phase II clinical trial.

PURPOSE: This trial aimed to evaluate the efficacy and safety of mitoxantrone hydrochloride liposome injection (Lipo-MIT) in advanced breast cancer (ABC). METHODS: In this randomized, open-label, active-controlled, single-center, phase II clinical trial, eligible patients were randomized in a ratio of 1:1 to receive Lipo-MIT or mitoxantrone hydrochloride injection (MIT) intravenously. The primary endpoint was objective response rate (ORR). The secondary endpoints were disease control rate (DCR), progression-free survival (PFS), and safety outcomes. RESULTS: Sixty patients were randomized to receive Lipo-MIT or MIT. The ORR was 13.3% (95% confidence interval (CI): 3.8-30.7%) for Lipo-MIT and 6.7% (95% CI: 0.8-22.1%) for MIT. The DCR was 50% (95% CI: 31.3-68.7%) with Lipo-MIT vs. 30% (95% CI: 14.7-49.4%) with MIT. The median PFS was 1.92 months (95% CI: 1.75-3.61) for Lipo-MIT and 1.85 months (95% CI: 1.75-2.02) for MIT. The most common toxicity was myelosuppression. Lipo-MIT resulted in an incidence of 86.7% of leukopenia and 80.0% of neutropenia, which was marginally superior to MIT (96.7% and 96.7%, respectively). Lipo-MIT showed a lower incidence of cardiovascular events (13.3% vs. 20.0%) and increased cardiac troponin T (3.3% vs. 36.7%); but higher incidence of anemia (76.7% vs. 46.7%), skin hyperpigmentation (66.7% vs. 3.3%), and fever (23.3% vs. 10.0%) than MIT. Conclusions The clinical benefit parameters of Lipo-MIT and MIT were comparable. Lipo-MIT provided a different toxicity profile, which might be associated with the altered distribution of the drug. Additional study is needed to elucidate the potential benefit of Lipo-MIT in ABC. CLINICAL TRIAL REGISTRATION: This study is registered with ClinicalTrials.gov (No. NCT02596373) on Nov 4, 2015.

Everolimus-Related Pneumonitis in Patients with Metastatic Breast Cancer: Incidence, Radiographic Patterns, and Relevance to Clinical Outcome.

BACKGROUND: This study investigated the incidence, radiographic patterns, and relevance to clinical outcome of everolimus-related pneumonitis (ERP) in patients with metastatic breast cancer (MBC). MATERIALS AND METHODS: Data of patients with MBC treated with everolimus who had baseline and at least one follow-up chest computed tomography (CT) were obtained from a medical electronic database system. An independent review of the CT scans of these patients was conducted by two radiologists (NCT03730428). Log-rank and Cox proportional hazard regression analyses were used for time-to-event analyses. RESULTS: ERP was radiographically detected in 45 of 86 patients (52.3%). In more than 80% of these patients, ERP occurred during the first 4 months of everolimus treatment. Only 14 of the 45 patients with ERP were symptomatic (31.1%). Symptoms included cough, fever, and shortness of breath. Bilateral and lower distribution of the pneumonitis was most common. In most of the cases, ground-glass opacities and reticular opacities were noticed. Elderly patients were more likely to develop ERP. Patients with ERP had significantly longer progression-free survival (PFS; 6.8 vs. 4.1 months, p = .024) and overall survival (OS; 42.8 vs. 21.3 months, p = .016). ERP was a predictor of OS improvement confirmed by multivariate Cox analysis (hazard ratio, 0.49; 95% confidence interval, 0.25-0.97; p = .040). CONCLUSIONS: ERP was noted in half of the patients with MBC treated with everolimus. Our data suggested that ERP was associated with improved prognosis and may be used as a biomarker for the efficacy of everolimus in MBC. Close monitoring, prompt diagnosis, and proper treatment for ERP are essential to maintain the quality of life of patients and achieve maximum treatment benefits. IMPLICATIONS FOR PRACTICE: Everolimus-related pneumonitis (ERP) is one of the most worrying drug adverse events, especially in Asian patients. However, little has been known about the clinical and radiographic details of ERP in patients with metastatic breast cancers (MBCs) treated with everolimus. The present study investigated the clinical characteristics, radiographic patterns, and its correlation with treatment outcome in patients with MBC. ERP was identified in more than half of patients with MBC during everolimus therapy and was associated with improved outcome. Close monitoring and prompt diagnosis and appropriate treatment for ERP are critical for the preservation of patients' quality of life and achievement of maximal treatment benefits.

Loss of polarity protein Par3 is mediated by transcription factor Sp1 in breast cancer.

Loss of polarity protein Par3 promotes breast cancer tumorigenesis and metastasis. The underlying molecular mechanisms of Par3 down-regulation and related prognostic significance in breast cancer remain unclear. Here, we discovered that Par3 down-regulation was associated with shorter relapse-free survival in Luminal A subtype of breast cancer. Par3 knockdown promoted breast cancer cells migration and invasion. Importantly, we identified that transcription factor Sp1 bound to PARD3 promoter region and induced Par3 expression. Breast cancer patients with low Sp1 showed significantly worse RFS and low expression level of Par3. Par3 over-expression partially reversed Sp1 knockdown induced migration and invasion. Together, decreased Sp1 level mediates Par3 down-regulation, which correlated with poor prognosis of ER + breast cancer patients, via reduced binding with PARD3 promoter.

Phase II trail of nab-paclitaxel in metastatic breast cancer patients with visceral metastases.

BACKGROUND: Visceral metastases account for 48-67% of metastatic breast cancer (MBC) patients and presage a worse overall survival. Previous study suggested potential effect of nab-paclitaxel on patients with visceral metastases subgroups. This phase II trial was conducted to explore the efficacy and safety of nab-paclitaxel in such a high-risk group of patients. METHODS: In this prospective, single-center, open-label, phase II study, MBC patients with visceral metastases (N = 80) received nab-paclitaxel (Abraxane, 125 mg/m2, D1, D8, D15 every 28 days). RESULTS: The median PFS was 5.1 months (95% CI: 4.2-6.0 months), with an ORR of 33.8% (95% CI 21.3-43.8%) and CBR of 66.2% (95% CI 56.3-75.0%). In univariate analysis, patients with premenopausal status had a trend of better treatment outcome. Multivariate analysis demonstrated non brain metastasis (adjusted HR 0.31, 95% CI 0.12-0.83, P = 0.019) and first line treatment (adjusted HR 0.37, 95% CI 0.17-0.81, P = 0.013) as independent predictors of longer PFS. The overall safety was acceptable with most common treatment-related, grade ≥ 3 toxicities of neutropenia (16.3%) and sensory neuropathy (3.7%). CONCLUSIONS: This phase II trial documented satisfactory efficacy and safety of nab-paclitaxel in MBC patients with visceral metastases, providing evidence for relative clinical practice. Patients in first line therapy had better treatment outcome. For patients with premenopausal status or brain metastasis, further alternatives (for example, combined chemotherapy or targeting therapy) might be required. This study also demonstrated the efficacy and safety of 125 mg/m2 nab-paclitaxel among Asian patients. TRIAL REGISTRATION: This research is registered under clinicaltrials.gov (NCT02687490, February 22, 2016).

A new method for detecting Na+ , K+ -ATPase activity by ICP-MS: Quantitative analysis on the inhibitory effect of rhein on Na+ , K+ -ATPase activity by ICP-MS in HCT116 cells.

Rhein is an active component from Chinese herbal medicine. It can cause diarrhea by inhibiting Na+ , K+ -ATPase activity on intestinal epithelial cells, thus decreasing the re-absorption of Na+ from intestinal tract to blood. However, when this Na+ , K+ -ATPase inhibition was quantitated by a colorimetric method that measures ATPase-catalyzed release of inorganic phosphorus, the data obtained were inconsistent and showed great variation. We developed a novel method using inductively coupled plasma mass spectrometry (ICP-MS) to quantitate the amount of intracellular Rb+ . This method largely mimics the 86 RbCl tracer flux assay, but it uses non-radioactive RbCl as a flux substrate. The results demonstrated that this method has better precision and accuracy than the conventional colorimetric method. More importantly, this method is free from radioactive substances, which is expected to make it safer and more convenient than the radioactive 86 RbCl tracer flux method. In conclusion, the ICP-MS method for Na+ , K+ -ATPase activity determination is novel and accurate. It can also provide a reference for studying the transport of other metal ions across membranes under biological conditions.

Cisplatin given at three divided doses for three consecutive days in metastatic breast cancer: an alternative schedule for one full dose with comparable efficacy but less CINV and hypomagnesaemia.

PURPOSE: Cisplatin, an effective medication for metastatic breast cancer (MBC), is recommended to be applied at the dose of 75 mg/m2 on day 1 every 3 weeks. However, the 75 mg/m2 schedule is often associated with a variety of side effects (such as vomiting and kidney toxicity), and time-consuming hydration treatment is usually needed. Divided dose (25 mg/m2 on day 1-3) without hydration is an alternative. This study aimed to compare the efficacy and toxicity profiles between these two dosage regimens. METHODS: Patients with MBC treated with cisplatin-based regimens in Fudan University Shanghai Cancer Center between December 2008 and June 2019 were retrospectively analyzed. Objective response rate (ORR), progression-free survival (PFS), and toxicity profiles were analyzed. RESULTS: 227 patients receiving a 1-day schedule and 256 patients receiving a 3-day schedule were included. Median PFS was 6.68 (5.66-7.70) months for patients in the 1-day schedule group and 6.70 (5.89-7.52) months for patients in the 3-day schedule group. There was no statistically significant difference in PFS between the two treatment groups (hazard ratio, 0.942; 95% CI 0.759 to 1.170; P = 0.589). The ORRs were comparable between the two groups. ORRs were 44.9% in 1-day schedule group and 44.5% in 3-day schedule group, respectively (P = 0.929). Compared with patients in the 3-day schedule group, patients in the 1-day schedule group experienced higher rates of chemotherapy-induced nausea and vomiting (CINV) (139 [61.2%] vs. 132 [51.6%], P = 0.033). The risk of hypomagnesaemia was also significantly higher (43.2% vs. 28.3%, P = 0.016) among patients receiving 1-day schedule (without magnesium supplementation). No other differences in adverse events were observed between the two groups. CONCLUSIONS: Cisplatin given at three divided doses with no hydration in MBC is a less toxic (less CINV and hypomagnesaemia) schedule with comparable efficacy. Thus, it may be a good alternative for one full-dose (75 mg/m2) schedule.

Retracted: Naturally Occurring Sesquiterpene Lactone-Santonin, Exerts Anticancer Effects in Multi-Drug Resistant Breast Cancer Cells by Inducing Mitochondrial Mediated Apoptosis, Caspase Activation, Cell Cycle Arrest, and by Targeting Ras/Raf/MEK/ERK Signaling Pathway.

It is now clear that the photomicrographs in Figure 2 are duplicates of the same image and that Figures 4 and 5 have been 'copied' from a publication "Lupeol triterpene exhibits potent antitumor effects in A427 human lung carcinoma cells via mitochondrial mediated apoptosis, ROS generation, loss of mitochondrial membrane potential and downregulation of m-TOR/PI3Ksol;AKT signalling pathway" by Wei He, Xiang Li, Shuyue Xia, PMID: 30003730. Because the manuscript contains non-credible results and has also breached copyright, this journal is retracting the above publication.

Clinical Outcomes of 130 Patients with Hormone Receptor-Positive and Human Epidermal Growth Factor Receptor 2-Negative Metastatic Breast Cancer Treated with Palbociclib plus Endocrine Therapy and Subsequent Therapy: A Real-World Single-Center Retrospective Study in China.

BACKGROUND This retrospective single-center study conducted in China aimed to investigate the clinical outcomes of patients with hormone receptor-positive (HR+) and human epidermal growth factor receptor 2-negative (HER2-) metastatic breast cancer (MBC) treated with palbociclib plus endocrine therapy (ET) and subsequent therapy. MATERIAL AND METHODS Eligible patients were women with HR+ and HER2- MBC who initiated palbociclib plus ET between September 2016 and August 2019 at Fudan University Shanghai Cancer Center. Clinical characteristics and efficacy data were retrospectively recorded from the electronic medical record system. RESULTS In total, 130 patients were included in the study, of whom 87.0% of patients started palbociclib on 125 mg/day, 8.5% of patients had dose reduction, and 2.3% of patients discontinued the treatment because of toxicity. Overall, the disease control rate was 77.4% and clinical benefit rate was 63.4%. After a median follow-up period of 10.6 months, the median progression-free survival was 9.2 months. There was limited efficacy in patients who received palbociclib as no less than a fourth line of ET, except for patients who added palbociclib to the ET, which they had acquired resistance to. After disease progression on palbociclib, further treatment with chemotherapy and ET had similar efficacy (P=0.571). CONCLUSIONS The findings from this real-world single-center study in China showed that treatment with palbociclib plus ET exhibited favorable efficacy and good tolerance in patients with HR+ and HER2- MBC, even in patients who were initially resistant to endocrine therapy, and there was no difference in outcomes between subsequent treatment with chemotherapy and ET.

Naturally Occurring Sesquiterpene Lactone-Santonin, Exerts Anticancer Effects in Multi-Drug Resistant Breast Cancer Cells by Inducing Mitochondrial Mediated Apoptosis, Caspase Activation, Cell Cycle Arrest, and by Targeting Ras/Raf/MEK/ERK Signaling Pathway.

BACKGROUND Sesquiterpene lactones have gained tremendous attention owing to their potent anticancer properties. The main focus of this study was to evaluate the anticancer effects of a naturally occurring sesquiterpene lactone, santonin, against human breast cancer SK-BR-3 cells. MATERIAL AND METHODS Cell counting kit 8 assay was used for the determination of cell viability. Apoptosis was detected by DAPI (4',6-diamidino-2-phenylindole) and annexin V/propidium iodide (IP) staining. Flow cytometry was used for cell cycle analysis and western blotting was used for the estimation of protein expression. RESULTS Results showed that santonin exerts significant anti-proliferative effects on the SK-BR-3 breast cancer cells in a concentration dependent manner. Santonin showed an IC50 of 16 µM against SK-BR-3 cells. DAPI staining showed that santonin caused DNA fragmentation in the SK-BR-3 cells, which is indicative of apoptosis. Annexin V/PI staining showed that apoptotic cell percentage increased up to 34.32% at 32 µM concentration of santonin. Santonin also caused an increase in the expression of Bax, caspase-3, and caspase-9, and a decrease in the expression of Bcl-2. Santonin also caused the arrest of the SK-BR-3 cells at the G2/M phase of the cell cycle and suppressed the expression of cyclin A and B1. Finally, santonin could also block the Raf/MEK/ERK pathway in breast cancer cells. CONCLUSIONS The findings of this study suggest the potential for the naturally occurring sesquiterpene lactone santonin in breast cancer treatment and also suggest that it could be developed as a promising anticancer agent.

Weekly albumin-bound paclitaxel/cisplatin versus gemcitabine/cisplatin as first-line therapy for patients with advanced non-small-cell lung cancer: A phase II open-label clinical study.

OBJECTIVE: The aim of this trial was to compare both the efficacy and the safety of a weekly nanoparticle albumin-bound paclitaxel (nab-paclitaxel) plus cisplatin vs. gemcitabine plus cisplatin in patients with advanced non-small-cell lung cancer (NSCLC). METHODS: A total of 84 participants received either 100 mg/m2 nab-paclitaxel each week on d 1, 8 and 15 of a 28 day cycle, as well as cisplatin 75 mg/m2 on d 1 every three weeks (nab-TP arm); or gemcitabine 1,000 mg/m2 on d 1 and 8, plus cisplatin 75 mg/m2 on d 1 every three weeks (GP arm). The primary end point was progression-free survival (PFS). The secondary end points were overall response rate (ORR) and overall survival (OS). RESULTS: According to our analysis, the median PFS was 4.8 months for the nab-TP arm vs. 5.2 months for the GP arm (P=0.55). Analysis showed the median OS was 14.6 months for participants who were in the nab-TP arm vs. 15.1 months for those in the GP arm (P=0.94). Besides, nab-TP showed OS advantages over GP in patients harboring epidermal growth factor receptor (EGFR) mutation (26.7 vs. 15.3 months, P=0.046) and patients with a performance status of 0 (23.5 vs. 14.7 months, P=0.020). It was found that incidences of drug-related grade 3 or 4 toxicities were comparable between the two treatment arms. CONCLUSIONS: Therefore, it can be seen that weekly nab-TP treatment has a similar efficacy and tolerability to GP treatment for patients who are undergoing their first-line treatment for NSCLC. It could be that survival differences among platinum doublets in the context of both EGFR mutation and performance status have the potential to be the basis for our further clinical trials.

Glucose regulated protein 78 (GRP78) inhibits apoptosis and attentinutes chemosensitivity of gemcitabine in breast cancer cell via AKT/mitochondrial apoptotic pathway.

The underlying mechanism of gemcitabine resistance during breast cancer treatment remains unclear. Glucose regulated protein 78 (GRP78) frequently triggered by anticancer agents, was substantially elevated in gemcitabine resistant sublines. Ectopic expression of GRP78 changes gemcitabine chemosensitivity and apoptosis levels in breast cancer cells. Further experiments showed an involvement of caspase 9, not caspase 8, in gemcitabine resistance and GRP78-mediated chemosensitivity, suggesting that mitochondria apoptotic pathway was activated by GRP78. This finding was further supported by the observations of AKT activation, Bcl-2 increase, Bax and Bim decrease. Conclusively, GRP78 plays a vital role in gemcitabine resistance and clinical strategy to improve gemcitabine efficacy in breast cancer by manipulating GRP78 should be explored.

MiRNA-21 induces epithelial to mesenchymal transition and gemcitabine resistance via the PTEN/AKT pathway in breast cancer.

Acquisition of gemcitabine resistance in breast cancer has not been fully clarified. Prior studies suggest that miRNAs are important to chemoresistance in solid tumors and we confirmed that miR-21 is involved in the development of gemcitabine resistance. Epithelial-to-mesenchymal transition (EMT) and AKT pathway activation were noted to be important to this resistance as well. PTEN, a direct target gene of miR-21, was significantly downregulated in gemcitabine-resistant breast cancer cells and restoration of PTEN expression blocked miR-21-induced EMT and gemcitabine resistance. Our data offer novel insight into gemcitabine resistance in breast cancer and suggest that miR-21 may be used to predict optimal breast cancer therapy and may be a potential therapeutic target for reversing gemcitabine resistance.

Malic enzyme 1 induces epithelial-mesenchymal transition and indicates poor prognosis in hepatocellular carcinoma.

Malic enzyme 1 (ME1) links the glycolytic and citric acid cycles and is important for NADPH production, glutamine metabolism, and lipogenesis. Recently, its deregulation has been implicated in the progression of various cancers. However, the role of ME1 in the progression of hepatocellular carcinoma (HCC) remains unclear. In this study, we utilized short hairpin RNA-mediated gene silencing to investigate the biological effects of ME1 depletion in HCC and determined its prognostic significance in HCC. ME1 expression was examined by real-time (RT)-PCR and Western blot using five HCC cell lines and one normal liver cell line. We used polyethylenimine nanoparticles to deliver a short hairpin RNA to induce cessation of ME1 expression in HCC cells. Changes in NADPH production and reactive oxygen species (ROS) production were studied. Metastatic potentials of HCC cells were evaluated in vitro. Furthermore, we evaluated the protein level of ME1 in para-tumor and cancerous tissues of 65 HCC patients with detailed clinical, pathological, and clinical follow-up data. Patients' survivals were further assessed as well. Upregulated ME1 expression was observed in HCC cell lines. Downregulation of ME1 attenuated NADPH production and stimulated ROS production. Silencing ME1 was noted to inhibit migratory and invasive properties of HCC cells by inducing the E-cadherin expression and decreasing of N-cadherin and vimentin expression in a ROS-dependent pathway. Overexpression of ME1 was observed in a major fraction of HCC samples. Higher level of ME1 in tumors was significantly associated with reduced overall survival (Kaplan-Meier analysis, P = 0.024) and reduced progression-free survival (Kaplan-Meier analysis, P = 0.011). Inhibition of ME1 expression decreases HCC metastasis via suppression of epithelial-mesenchymal transition (EMT) processes in ROS-induced pathways. ME1 overexpression associates with unfavorable prognoses in patients with HCC, suggesting that ME1 is a poor prognostic predictor of hepatocellular carcinoma.

Establishment of monoclonal HCC cell lines with organ site-specific tropisms.

BACKGROUND: Organ site-specific metastasis is an ominous feature for most poor-prognostic hepatocellular carcinoma (HCC) patients. Cancer cell lines and animal models are indispensable for investigating the molecular mechanisms of organ specific tropism. However, till now, little is known about the drivers in HCC metastatic tropism, and also no effective way has been developed to block the process of tropistic metastasis. METHODS: In this study, we established several monoclonal HCC cell lines from HCCLM3-RFP together with their xenograft models, and then analyzed their metastatic potentials and tropisms using in-vitro and in-vivo assays, and finally elucidated the driving forces of HCC tropistic metastases. RESULTS: Six monoclonal cell lines with different organ site-specific tropism were established successfully. SPARC, VCAM1 and ANGPTL4 were found positively correlated with the potentials of lung metastasis, while ITGA1 had a positive relation to lymph node metastasis of enterocoelia. CONCLUSIONS: By our powerful platforms, HCC metastatic tropisms in clinic could be easily mimicked and recapitulated for exploring the bilateral interactions between tumor and its microenvironment, elucidating the drivers of HCC metastatic tropisms, and testing anti-cancer effects of newly developed agent in pre-clinical stage.

MiR-612 suppresses the stemness of liver cancer via Wnt/ß-catenin signaling.

Previous research showed that microRNA-612 (miR-612) has inhibitory effects on cell proliferation, migration, invasion, and metastasis of hepatocellular carcinoma (HCC). AKT2 was confirmed to be a direct target of miR-612, through which the epithelial-mesenchymal transition (EMT) and metastasis of HCC were inhibited. Our present findings reveal that miR-612 is able to suppress the stemness of HCC by reducing the number and size of tumorspheres as well as clone formation in soft agar, and to relieve drug resistance to cisplatin and 5-fluorouracil. In addition, miR-612 hampered the capacity of tumorigenesis in NOD/SCID mice and redistributed the tumor invasive frontier of miR-612-modulating cells. Finally, our findings suggest that Wnt/ß-catenin signaling is required in the regulation of EMT-associated stem cell-like traits by miR-612.

Emerging roles of tripartite motif family proteins (TRIMs) in breast cancer.

Breast cancer (BC) is the most common malignant tumor worldwide. Despite enormous progress made in the past decades, the underlying mechanisms of BC remain further illustrated. Recently, TRIM family proteins proved to be engaged in BC progression through regulating various aspects. Here we reviewed the structures and basic functions of TRIM family members and first classified them into three groups according to canonical polyubiquitination forms that they could mediate: K48- only, K63- only, and both K48- and K63-linked ubiquitination. Afterwards, we focused on the specific biological functions and mechanisms of TRIMs in BCs, including tumorigenesis and invasiveness, drug sensitivity, tumor immune microenvironment (TIME), cell cycle, and metabolic reprogramming. We also explored the potential of TRIMs as novel biomarkers for predicting prognosis and future therapeutic targets in BC.

TSPAN8+ myofibroblastic cancer-associated fibroblasts promote chemoresistance in patients with breast cancer.

Cancer-associated fibroblasts (CAFs) are abundant stromal cells in the tumor microenvironment that promote cancer progression and relapse. However, the heterogeneity and regulatory roles of CAFs underlying chemoresistance remain largely unclear. Here, we performed a single-cell analysis using high-dimensional flow cytometry analysis and identified a distinct senescence-like tetraspanin-8 (TSPAN8)+ myofibroblastic CAF (myCAF) subset, which is correlated with therapeutic resistance and poor survival in multiple cohorts of patients with breast cancer (BC). TSPAN8+ myCAFs potentiate the stemness of the surrounding BC cells through secretion of senescence-associated secretory phenotype (SASP)-related factors IL-6 and IL-8 to counteract chemotherapy. NAD-dependent protein deacetylase sirtuin 6 (SIRT6) reduction was responsible for the senescence-like phenotype and tumor-promoting role of TSPAN8+ myCAFs. Mechanistically, TSPAN8 promoted the phosphorylation of ubiquitin E3 ligase retinoblastoma binding protein 6 (RBBP6) at Ser772 by recruiting MAPK11, thereby inducing SIRT6 protein destruction. In turn, SIRT6 down-regulation up-regulated GLS1 and PYCR1, which caused TSPAN8+ myCAFs to secrete aspartate and proline, and therefore proved a nutritional niche to support BC outgrowth. By demonstrating that TSPAN8+SIRT6low myCAFs were tightly associated with unfavorable disease outcomes, we proposed that the combined regimen of anti-TSPAN8 antibody and SIRT6 activator MDL-800 is a promising approach to overcome chemoresistance. These findings highlight that senescence contributes to CAF heterogeneity and chemoresistance and suggest that targeting TSPAN8+ myCAFs is a promising approach to circumvent chemoresistance.