YTHDF1's Regulatory Involvement in Breast Cancer Prognosis, Immunity, and the ceRNA Network.

YTH N6-methyladenosine RNA binding protein 1 (YTHDF1), an m6A reader, has a role in the development and progression of breast cancer as well as the immunological microenvironment. The networks of competing endogenous RNA in cancer have received much attention in research. In tumor gene therapy, the regulatory networks of m6A and competing endogenous RNA are increasingly emerging as a new route. We evaluated the relationship between the YTHDF1 expression, overall survival, and clinicopathology of breast cancer using TCGA, PrognoScan, and other datasets. We used Western blot to demonstrate that YTHDF1 is substantially expressed in breast cancer tissues. Furthermore, we explored YTHDF1's functions in the tumor mutational burden, microsatellite instability, and tumor microenvironment. Our findings indicate that YTHDF1 is a critical component of the m6A regulatory proteins in breast cancer and may have a particular function in the immunological microenvironment. Crucially, we investigated the relationship between YTHDF1 and the associated competitive endogenous RNA regulatory networks, innovatively creating three such networks (Dehydrogenase/Reductase 4-Antisense RNA 1-miR-378g-YTHDF1, HLA Complex Group 9-miR-378g-YTHDF1, Taurine Up-regulated 1-miR-378g-YTHDF1). Furthermore, we showed that miR-378g could inhibit the expression of YTHDF1, and that miR-378g/YTHDF1 could impact MDA-MB-231 proliferation. We speculate that YTHDF1 may serve as a biomarker for poor prognosis and differential diagnosis, impact the growth of breast cancer cells via the ceRNA network axis, and be a target for immunotherapy against breast cancer.

Exosomal miRNAs assist in the crosstalk between tumor cells and immune cells and its potential therapeutics.

Exosomes are small extracellular vesicles that carry active substances (including proteins, lipids, and nucleic acids) and are essential for homeostasis and signal transmission. Recent studies have focused on the function of exosomal miRNAs in tumor progression. Researchers have expanded the use of exosomes and miRNAs as potential therapeutic tools and biomarkers to detect tumor progression. Immune cells, as an important part of the tumor microenvironment (TME), secrete a majority of exosome-derived miRNAs involved in the biological processes of malignancies. However, the underlying mechanisms remain unclear. Currently, there is no literature that systematically summarizes the communication of exosome-derived miRNAs between tumor cells and immune cells. Based on the cell specificity of exosome-derived miRNAs, this review provides the first comprehensive summary of the significant miRNAs from the standpoint of exosome sources, which are tumor cells and immune cells. Furthermore, we elaborated on the potential clinical applications of these miRNAs, attempting to propose existing difficulties and future possibilities in tumor diagnostics and therapy.

Tumor-derived Cav-1 promotes pre-metastatic niche formation and lung metastasis in breast cancer.

Rationale: Breast cancer (BC), as one of the most frequently diagnosed cancer, has a poor prognosis due to the development of distant metastasis. Among the BC metastatic sites, lung is one of the most common sites. Caveolin-1 (Cav-1) is a functional membrane protein that plays a vital role in tumor metastasis. Although studies have revealed that Cav-1 levels were elevated in patients with advanced cancer, whether Cav-1 affects BC lung metastasis by influencing the formation of pre-metastatic niche (PMN) through exosomes has not been explored. Methods: Differential ultracentrifugation, transmission electron microscopy and nanoparticle tracking analysis were used to verify the presence of exosomes. Transwell assays were used to examine the biological effects of exosomes containing Cav-1. Both in vitro cell cultures and mammary tumor cell-induced mouse models were used to assess the lung metastasis. The regulatory mechanisms of PMN formation were revealed using western blot, flow cytometry, RT-qPCR, immunofluorescence assays, gene overexpression assays and RNA interference assays. Results: Exosomes have critical functions in transporting Cav-1 between primary BC and metastatic organ microenvironments. Cav-1 in BC-derived exosomes can act as a signaling molecule to mediate intercellular communication and regulate the PMN before lung metastasis by regulating the expression of PMN marker genes and inflammatory chemokines in lung epithelial cells, promoting the secretion of tenascin-C (TnC) in lung fibroblasts to cause extracellular matrix (ECM) deposition, and inhibiting the PTEN/CCL2/VEGF-A signaling pathway in lung macrophages to facilitate their M2-type polarization and angiogenesis. Conclusion: Our study investigated the mechanisms of lung PMN formation induced by Cav-1 in BC-derived exosomes. Our data may provide new directions for exploring the mechanisms and developing treatment strategies of BC lung metastasis.

Drug Repurposing Screen Identifies Foxo1-Dependent Angiopoietin-2 Regulation in Sepsis.

OBJECTIVE: The recent withdrawal of a targeted sepsis therapy has diminished pharmaceutical enthusiasm for developing novel drugs for the treatment of sepsis. Angiopoietin-2 is an endothelial-derived protein that potentiates vascular inflammation and leakage and may be involved in sepsis pathogenesis. We screened approved compounds for putative inhibitors of angiopoietin-2 production and investigated underlying molecular mechanisms. DESIGN: Laboratory and animal research plus prospective placebo-controlled randomized controlled trial (NCT00529139) and retrospective analysis (NCT00676897). SETTING: Research laboratories of Hannover Medical School and Harvard Medical School. PATIENTS: Septic patients/C57Bl/6 mice and human endothelial cells. INTERVENTIONS: Food and Drug Administration-approved library screening. MEASUREMENTS AND MAIN RESULTS: In a cell-based screen of more than 650 Food and Drug Administration-approved compounds, we identified multiple members of the 3-hydroxy-3-methyl-glutaryl-CoA reductase inhibitor drug class (referred to as statins) that suppressed angiopoietin-2. Simvastatin inhibited 3-hydroxy-3-methyl-glutaryl-CoA reductase, which in turn activated PI3K-kinase. Downstream of this signaling, PI3K-dependent phosphorylation of the transcription factor Foxo1 at key amino acids inhibited its ability to shuttle to the nucleus and bind cis-elements in the angiopoietin-2 promoter. In septic mice, transient inhibition of angiopoietin-2 expression by liposomal siRNA in vivo improved absolute survival by 50%. Simvastatin had a similar effect, but the combination of angiopoietin-2 siRNA and simvastatin showed no additive benefit. To verify the link between statins and angiopoietin-2 in humans, we performed a pilot matched case-control study and a small randomized placebo-controlled trial demonstrating beneficial effects on angiopoietin-2. CONCLUSIONS: 3-hydroxy-3-methyl-glutaryl-CoA reductase inhibitors may operate through a novel Foxo1-angiopoietin-2 mechanism to suppress de novo production of angiopoietin-2 and thereby ameliorate manifestations of sepsis. Given angiopoietin-2's dual role as a biomarker and candidate disease mediator, early serum angiopoietin-2 measurement may serve as a stratification tool for future trials of drugs targeting vascular leakage.

[Secondary laryngeal tuberculosis at high altitudes of Tibet].

OBJECTIVE: To improve the diagnostic and therapeutic efficiency for secondary laryngeal tuberculosis through an analysis on the clinical features of patients with this disease. METHOD: A retrospective study was made among 49 cases with laryngeal tuberculosis treated in Tibetan General Hospital of Chinese PLA, and the clinical data were carefully analyzed to summarize the clinical experience of this disease. RESULT: Of 49 patients, 24 cases had 1 year history, 11 cases had 1 to 3 years, 9 cases had 3 to 5 years, 5 cases had 5 years or more. Thirty-eight patients had the history of tuberculosis and 11 had none. Thirty-four patients had taken anti-tuberculosis drugs but none had standard therapy as demanded. All cases had mild general symptoms (mild fever, night sweats, weight loss, et al) and atypical local symptoms (hoarseness, sore throat). Therefore, 42 cases were misdiagnosed as non-specific chronic laryngitis, of which 15 cases got worse after oral administration or inhaling of steroid hormones. Seven persons were misdiagnosed as laryngeal cancer. All patients were confirmed pulmonary tuberculosis by X ray exam or CT scanning. Twelve cases had strong positive PPD tests and 2 cases were detected positive by sputum smear. All patients was treated by standard systematic and local chemical therapy against tuberculosis (inhaling of antituberculosis drugs for 1 to 2 months). All were cured but one died in a road accident, and none had recurrence after 1- to 9- year follow-up. CONCLUSION: All of those the patients with long period hoarseness and sore throat should take chest CT scan or X-ray exam for the highest incidence of pulmonary tuberculosis at high altitudes. CT scanning is the prefer for its high resolution. Pathological biopsy and diagnostic therapy should be taken to make accurate diagnosis. Usually steroid hormones should not be recommended.

[Surgical treatment of 154 patients with non-traumatic acute lower limb ischemia].

OBJECTIVE: To analyze the surgical treatment and prognosis of non-traumatic acute lower limb ischemia, and compare the morbidity and prognosis of acute arterial embolism and acute arterial thrombosis. METHODS: The clinical data of 154 acute lower limb ischemia patients surgically treated from July 1999 to December 2007 were retrospectively analyzed. Fogarty catheter embolectomy was used in all patients; in which, 128 cases underwent Fogarty catheter embolectomy only, 8 cases Fogarty catheter embolectomy combined with endarterectomy, 13 cases Fogarty catheter embolectomy combined with vascular reconstruction with prosthetic graft or great saphenous vein, 5 cases Fogarty catheter embolectomy combined with amputation. The patients were divided into two groups according to pathogenesis: acute arterial embolism group (99 cases) and acute arterial thrombosis group (55 cases). The morbidity, amputation, perioperative mortality rates and high risk factors of amputation in the two groups were compared. RESULTS: Female experienced acute arterial embolism more often than man (60.6% vs 39.4%, P < 0.05), and more acute arterial thrombosis occurred in man (72.7% vs 27.3%, P < 0.05). The amputation rate of all cases was 9.7%, and perioperative mortality rate was 11.7%. The amputation rate in acute arterial embolism group was lower than acute arterial thrombosis group (5.1% vs 18.2%, P < 0.05). The perioperative mortality rates in the two groups were equal (11.1% vs 12.7%, P > 0.05). The statistically high risk factor of amputation for two groups was ischemic time, and smoking and diabetes were high risk factors for acute arterial thrombosis. CONCLUSIONS: Men experiences acute arterial thrombosis more often, and women experiences acute arterial embolism more often. The amputation rate of acute arterial embolism is lower than acute arterial thrombosis, and acute arterial thrombosis has more high risk factors of amputation.

[Endovascular therapy and arterial bypass for subclavian artery occlusion].

OBJECTIVE: To investigate the effect of endovascular therapy and artery bypass for subclavian artery occlusion disease and to explore a suitable therapeutic procedure. METHODS: Thirty-nine patients with subclavian artery occlusive disease received endovascular therapy or arterial bypass from June 1997 to May 2004. Twenty-seven endovascular stenting were performed on 26 patients through the femoral artery (n = 14) or combined brachial artery (n = 12). Retrograde endovascular balloon angioplasty and stent placement were performed on 12 patients. Eight subclavian arteries were punctured with ultrasound localization. On account of unsuccessful stenting, 13 cases received arterial bypass. In addition, endovascular stenting were performed on 9 cases with carotid or vertebrarterial stenoses. RESULTS: The blood pressure difference was less than 10 mm Hg between the treated and the healthy arms in all 39 patients. The ratio of healthy/diseased side of the mean blood pressure index increased from 0.62 +/- 0.11 preoperatively to 0.98 +/- 0.04 postoperatively (P < 0.01). The mean patency time for endovascular therapy and arterial bypass was (57.6 +/- 3.7) and (60.2 +/- 7.2) months, respectively. CONCLUSIONS: Both endovascular therapy and arterial bypass have good curative effect for subclavian artery occlusion. Endovascular therapy is the preferred treatment for subclavian artery occlusion with mini-trauma and safety.

[Clinical analysis on treatment for superficial varicosities of low limbs with minimally invasive rotary varicotomy].

OBJECTIVE: To evaluate therapeutic efficacy of minimally invasive rotary varicotomy (TriVex) for superficial varicosities of low limbs and summarize our therapeutic experiences. METHODS: One hundred and eighty-two cases (totally 216 lower limbs) were applied minimally invasive rotary varicotomy (TriVex) and relative clinical data was analyzed. RESULTS: The average operation time for each limb was 48 min. Discomfort and pain of lower limbs disappeared in all of patients after operation. There was no residual of superficial varicosities. There was no severe complication and recurrence of varicosities. The postoperative complication rate was 21.3%. CONCLUSIONS: For treatment of superficial varicosities of low limbs, minimally invasive rotary varicotomy (TriVex) have many advantages including minimal invasion, quick recovery, safety and cosmetic effect. In addition, it has extensive indications and satisfactory therapeutic efficacy. It would be beneficial to master the operative techniques of key procedures. It could decrease complications and get better curative effects.

[Follow-up study in endovascular therapy for the renal artery stenosis].

OBJECTIVE: To evaluate the safety and efficacy of endovascular therapy for renal artery stenosis. METHODS: Percutaneous transluminal renal angioplasty with stent (PTRAS) was performed on 33 consecutive patients with severe renal artery stenosis who suffered from poorly controlled hypertension or renal dysfunction. They were subsequently underwent 7 to 49 months clinical follow up for the effect of the procedure on renal function, blood pressure control, mortality. RESULTS: Angiographic success was obtained in 32 (97.0%) of the 33 patients. The mortality was 18.2%. After PTRAS, two (6.1%) died of myocardial infarction within 4 months. Four (12.1%) patients with preoperative serum creatinine (Scr) > or = 177 micromol/L died of uraemia within 17 approximately 28 months. Twelve and twenty-four months after the procedure, systolic and diastolic blood pressure of 26 (78.8%) cases with preoperative Scr < 177 micromol/L significantly decreased (P < 0.05), with less antihypertensive medications taken and satisfactory renal function. CONCLUSION: For patients without serious cardiorenal disease, PTRAS has a beneficial effect on blood pressure and renal function. For patients with serious cardiorenal disease or preoperative Scr > or = 177 micromol/L, the mortality is higher. PTRAS should be performed prudently. The preservation of renal function may be enhance by using renal protection device.