Membrane-Active All-Hydrocarbon-Stapled α-Helical Amphiphilic Tat Peptides: Broad-Spectrum Antibacterial Activity and Low Incidence of Drug Resistance.

Multidrug resistance against conventional antibiotics has dramatically increased the difficulty of treatment and accelerated the need for novel antibacterial agents. The peptide Tat (47-57) is derived from the transactivating transcriptional activator of human immunodeficiency virus 1, which is well-known as a cell-penetrating peptide in mammalian cells. However, it is also reported that the Tat peptide (47-57) has antifungal activity. In this study, a series of membrane-active hydrocarbon-stapled α-helical amphiphilic peptides were synthesized and evaluated as antibacterial agents against Gram-positive and Gram-negative bacteria, including multidrug-resistant strains. The impact of hydrocarbon staple, the position of aromatic amino acid residue in the hydrophobic face, the various types of aromatic amino acids, and the hydrophobicity on bioactivity were also investigated and discussed in this study. Among those synthesized peptides, analogues P3 and P10 bearing a l-2-naphthylalanine (Φ) residue at the first position and a Tyr residue at the eighth position demonstrated the highest antimicrobial activity and negligible hemolytic toxicity. Notably, P3 and P10 showed obviously enhanced antimicrobial activity against multidrug-resistant bacteria, low drug resistance, high cell selectivity, extended half-life in plasma, and excellent performance against biofilm. The antibacterial mechanisms of P3 and P10 were also preliminarily investigated in this effort. In conclusion, P3 and P10 are promising antimicrobial alternatives for the treatment of the antimicrobial-resistance crisis.

Development of a Decafluorobiphenyl Cyclized Peptide Targeting the NEMO-IKKα/ß Interaction that Enhances Cell Penetration and Attenuates Lipopolysaccharide-Induced Acute Lung Injury.

Aberrant canonical NF-κB signaling has been implicated in diseases, such as autoimmune disorders and cancer. Direct disruption of the interaction of NEMO and IKKα/ß has been developed as a novel way to inhibit the overactivation of NF-κB. Peptides are a potential solution for disrupting protein-protein interactions (PPIs); however, they typically suffer from poor stability in vivo and limited tissue penetration permeability, hampering their widespread use as new chemical biology tools and potential therapeutics. In this work, decafluorobiphenyl-cysteine SNAr chemistry, molecular modeling, and biological validation allowed the development of peptide PPI inhibitors. The resulting cyclic peptide specifically inhibited canonical NF-κB signaling in vitro and in vivo, and presented positive metabolic stability, anti-inflammatory effects, and low cytotoxicity. Importantly, our results also revealed that cyclic peptides had huge potential in acute lung injury (ALI) treatment, and confirmed the role of the decafluorobiphenyl-based cyclization strategy in enhancing the biological activity of peptide NEMO-IKKα/ß inhibitors. Moreover, it provided a promising method for the development of peptide-PPI inhibitors.

Long-term outcomes of endoscopic or surgical resection in T1 colorectal cancer patients: a retrospective cohort study.

BACKGROUND: The personalized treatments of T1 colorectal cancer (CRC) remains controversial. We compared the long-term outcomes of T1 CRC patients after endoscopic resection (ER) and surgery, and evaluated the risk factors for the long-term prognosis. METHODS: T1 CRCs after resection at the Cancer Hospital, Chines Academy of Medical Sciences from June 2011 to November 2021 were reviewed. High-risk factors included positive resection margin, poor differentiation, deep submucosal invasion (DSI ≥ 1000 µm), lymphovascular invasion and intermediate/high tumor budding. Comparative analyses were conducted based on three treatment methods: follow-up after ER (Group A), additional surgery after ER (Group B) and initial surgery (Group C). The primary endpoints included recurrence-free survival (RFS) and overall survival (OS). Cox proportional hazard regression models were constructed to identify risk factors for RFS and OS. RESULTS: A total of 528 patients were enrolled (173 patients in Group A, 102 patients in Group B, 253 patients in Group C). The 3-year RFS, 5-year RFS, 3-year OS, and 5-year OS rates were 96.7%, 94.7%, 99.1%, and 97.8%, respectively. In the absence of other high-risk factors, RFS (P = 0.321) and OS (P = 0.155) of patients with DSI after ER were not inferior to those after surgery. Multivariate analyses identified sex (HR 0.379; 95% CI 0.160-0.894), Charlson comorbidities index (CCI) (HR 3.330; 95% CI 1.571-7.062), margin (HR 8.212; 95% CI 2.325-29.006), and budding (HR 3.794; 95% CI 1.686-8.541) as independent predictive factors of RFS, and identified CCI (HR 10.266; 95% CI 2.856-36.899) as an independent predictive factor of OS. CONCLUSION: The long-term outcomes of ER are comparable to those of surgery in T1 CRC patients with DSI when other high-risk factors are negative. Resection margin, tumor budding, sex, and CCI may be the most important long-term prognostic factors for T1 CRC patients.

A strategy combining endoscopic hand-suturing with clips for closure of rectal defects after endoscopic submucosal dissection with or without myectomy (with video).

BACKGROUND AND AIMS: Endoscopic hand-suturing (EHS) has been preliminarily demonstrated to be effective in closing defects after endoscopic submucosal dissection (ESD), but it is not easily performed. We proposed a strategy combining EHS with clips (EHS-Clips) and explored its effectiveness in closing rectal defects after ESD or ESD with myectomy (ESD-ME). METHODS: In this observational study, data from patients with rectal defects closed using EHS-Clips were reviewed. EHS-Clips refers to a strategy where defects are sutured as much as possible by EHS first, with clips being used to close the remaining parts of defects that cannot be completely sutured. The primary endpoints included complete closure rate, delayed bleeding (DB) rate, and sustained closure rate. Logistic regression analyses were performed to identify risk factors for the sustained closure. RESULTS: All 49 (100%) defects (42 ESD defects and 7 ESD-ME defects) were completely closed through the strategy of EHS-Clips, with 35 (71.4%) through EHS alone and 14 (28.6%) through EHS and additional clips. No patients experienced DB. Thirty-six (73.5%) defects remained sustained closure on postoperative days 3 to 5 (73.8% for ESD defects vs 71.4% for ESD-ME defects). The multivariate analyses identified a stitch margin of ≥5 mm (hazard ratio, 0.313; 95% confidence interval, 0.023-0.781; P = .009) as the only independent advantage factor for the sustained closure. CONCLUSIONS: EHS-Clips can be used to effectively close the rectal defects after ESD or ESD-ME and prevent DB. Complete suture with a stitch margin of ≥5 mm may achieve more reliable sustained closure.

Management Strategies for Acute Type A Aortic Dissection Complicated By Limb Malperfusion.

BACKGROUND: Acute type A aortic dissection complicated by limb malperfusion presents a risk of mortality to the patients. Debates exist regarding management, whether focused on reperfusion first or immediate repair. Here, we aimed to describe our experience with the management of acute type A aortic dissection (ATAAD) complicated by limb malperfusion. METHODS: From January 1, 2020 to December 31, 2021, 22 consecutive patients were admitted to Xiamen Cardiovascular Hospital, due to acute type A aortic dissection complicated by limb malperfusion. All perioperative variables were recorded and analyzed. Limb malperfusion was diagnosed, according to the clinical symptoms, computed tomography angiography, and laboratory test. We adopted the clinical categories of acute limb ischemia to stratify severity of limb ischemia. Surgery strategies are as follows: Reperfusion first followed by central repair, immediate central repair, and immediate central repair followed by stenting. RESULTS: There were 21 males and one female with an average of 53.3±11.7 years. Management strategies were as follows: immediate central repair using total arch replacement with frozen elephant trunk in 15 patients, endovascular stenting followed by central repair in four patients, and endovascular stenting after central repair in two patients. The average extracorporeal circulation time was 258.8 ± 70.5 min; the average aortic cross-clamp time was 177.9 ± 54.2 min; and the average circulatory arrest time was 45.5 ± 13.1 min. The early mortality rate was 13.6% (3/22). Two patients left the hospital voluntarily, due to cerebral infarction and bleeding. One patient underwent fasciotomy for osteofascial compartment syndrome and uneventfully was discharged. Six patients underwent continuous renal replacement therapy and hemoperfusion. CONCLUSION: Central repair is safe and feasible for ATAAD complicated with limb malperfusion. For serious limb malperfusion, endovascular stenting followed by central repair is a good choice with continuous renal replacement therapy (CRRT) and hemoperfusion. Hospital mortality rate is high in cases with multiple organ malperfusion.

Postoperative Myocardial Infarction in Acute Type A Aortic Dissection: A Case Report.

Postoperative myocardial infarction (POMI) in acute type A aortic dissection rarely has been reported, we report a case of postoperative myocardial infarction in acute type A aortic dissection, and the clinical presentation and possible mechanisms are described. This case illustrates that postoperative myocardial infarction in acute type A aortic dissection is a rare fatal complication in patients without coronary lesions or coronary malperfusion before aortic repair. Type 2 myocardial infarction may account for POMI. Effective treatment may include anticoagulation therapy, volume adjustment, blood pressure support, administration of blood products, heart rate control, and individualized respiratory support.

A Submucosal Tumor-like Lesion of the Cervical Esophagus Similar to the Tonsillar Structures of Waldeyer's Ring: A Case Report.

Esophageal submucosal tumors are rare, but their pathological types are diverse. In addition to the relatively common leiomyomas, some rare submucosal lesions are occasionally reported. Waldeyer's ring is described as a unique subtype of mucosa-associated lymphoid tissue, located in the naso-oropharynx. Studies have reported that Waldeyer's ring is the most common site of primary extranodal lymphoma in the head and neck. Interestingly, we encountered an esophageal submucosal tumor-like lesion similar to the tonsillar structures of Waldeyer's ring. A 38-year-old man underwent esophagoscopy after experiencing swallowing discomfort for 3 months. A protruding submucosal mass with slightly rough mucosa was found at the cervical esophagus approximately 20 cm from the incisors. Considering the possibility of the coexistence of a submucosal tumor and a mucosal lesion, as well as the continuous symptoms of swallowing discomfort, the patient underwent endoscopic submucosal dissection. The lesion was removed en bloc. However, histology revealed a lesion similar to the tonsillar structure of Waldeyer's ring between the lamina propria and submucosa. The patient was followed up for 6 months without recurrence or complaints. We report a new submucosal lesion and discuss its origin and treatment. Diagnostic ESD might be an effective option until its malignant potential is clarified.

Antepartum acute Stanford type A aortic dissection: a case report and literature review.

BACKGROUND: Aortic dissection in pregnancy is a life-threatening event that is associated with high maternal and foetal mortality. Most cases occur during the third trimester of pregnancy, Herein, we describe a case of a pregnant woman with acute type A aortic dissection at 28 weeks of gestation. CASE PRESENTATION: A previously healthy, 24-year-old gravida 2 para 1 woman was brought to the emergency department during at the 28 weeks of gestation and diagnosed with acute type A aortic dissection. Cesarean section was performed with the cardiac surgical team on standby for cardiopulmonary bypass and the patient delivered a baby weighing 1000 g. After the operation, we performed the Beatall procedure and total arch replacement with FET using the deep hypothermic circulatory arrest technique. Both the mother and child survived and recovered well. A review of the literature on antepartum acute aortic dissection during pregnancy is also presented. CONCLUSION: Women should have a comprehensive, systematic physical examination before getting pregnant. Women at high risks of aortic dissection must undergo multidisciplinary evaluation and be counseled before pregnancy, once they become pregnant, their consistent aortic root diameter should be consistently monitored, and their blood pressure strictly controlled.

Poorer Survival in Patients with Cecum Cancer Compared with Sigmoid Colon Cancer.

Background and Objectives: An increasing number of studies have shown the influence of primary tumor location of colon cancer on prognosis, but the prognostic difference between colon cancers at different locations remains controversial. After comparing the prognostic differences between left-sided and right-sided colon cancer, the study subdivided left-sided and right-sided colon cancer into three parts, respectively, and explored which parts had the most significant prognostic differences, with the aim to further analyze the prognostic significance of primary locations of colon cancer. Materials and Methods: Clinicopathological data of patients with colon cancer who underwent radical surgery from the Surveillance, Epidemiology, and End Results Program database were analyzed. The data was divided into two groups (2004−2009 and 2010−2015) based on time intervals. Two tumor locations with the most significant survival difference were explored by using Cox regression analyses. The prognostic difference of the two locations was further verified in survival analyses after propensity score matching. Results: Patients with right-sided colon cancer had worse cancer-specific and overall survival compared to left-sided colon cancer. Survival difference between cecum cancer and sigmoid colon cancer was found to be the most significant among six tumor locations in both 2004−2009 and 2010−2015 time periods. After propensity score matching, multivariate analyses showed that cecum cancer was an independent unfavorable factor for cancer specific survival (HR [95% CI]: 1.11 [1.04−1.17], p = 0.001 for 2004−2009; HR [95% CI]: 1.23 [1.13−1.33], p < 0.001 for 2010−2015) and overall survival (HR [95% CI]: 1.09 [1.04−1.14], p < 0.001 for 2004−2009; HR [95% CI]: 1.09 [1.04−1.14], p < 0.001 for 2010−2015) compared to sigmoid colon cancer. Conclusions: The study indicates the prognosis of cecum cancer is worse than that of sigmoid colon. The current dichotomy model (right-sided vs. left-sided colon) may be inappropriate for the study of colon cancer.

Corrigendum: EXOSC5 as a Novel Prognostic Marker Promotes Proliferation of Colorectal Cancer via Activating the ERK and AKT Pathways.

[This corrects the article DOI: 10.3389/fonc.2019.00643.].

NARFIB: A Novel Prognostic Score Based on the Neutrophil-to-Albumin Ratio and Fibrinogen Can Predict the Prognosis of Gastrointestinal Stromal Tumors.

OBJECTIVE: The neutrophil-to-albumin ratio (NAR) and fibrinogen are significantly related to tumor progression. The present study evaluated the prognostic impact of the NAR plus fibrinogen concentration in gastrointestinal stromal tumor (GIST) cases. METHODS: The baseline characteristics, postoperative NAR, and fibrinogen concentrations were retrospectively analyzed for 229 Chinese patients who underwent radical gastrectomy for GIST. Receiver operating characteristic (ROC) curves were applied to estimate the optimal critical points for NAR and fibrinogen. Cox regression analysis was applied to determine significant prognostic variables. RESULTS: Multivariate analyses revealed that poor recurrence-free survival was associated with elevated values for fibrinogen (hazard ratio [HR]: 5.015, 95% confidence interval [CI]: 1.993-12.619, P=0.001) and NAR (HR: 4.669, 95% CI: 1.776-12.273, P = 0.002). Combining fibrinogen and the NAR into the NARFIB score provided an area under the ROC curve of 0.833, which was greater than the areas for NAR (0.708) or fibrinogen (0.778). When the NAR and fibrinogen were replaced by the NARFIB score in the multivariate analysis, the independent prognosticators were tumor site (HR: 2.927, 95% CI: 1.417-6.045, P=0.004), mitotic index (HR: 2.661, 95% CI: 1.110-6.380, P=0.028), and the NARFIB score (HR: 14.116, 95% CI: 3.243-61.443, P<0.001). The NARFIB score retained its prognostic significance in various subgroup analyses and was significantly related to gender, surgical approach, tumor size, mitosis, tumor site, risk classification, and recurrence. CONCLUSION: These results suggest that the NARFIB score may help guide prognostication and risk stratification for GIST, which might benefit from targeted therapy.

A modified frozen elephant trunk technique for acute Stanford type A aortic dissection.

BACKGROUND: Acute Stanford type A aortic dissection is often fatal, with a high mortality rate and requiring emergency intervention. Salvage surgery aims to keep the patient alive by addressing severe aortic regurgitation, tamponade, primary tear, and organ malperfusion and, if possible, prevent the late dissection-related complications in the proximal and downstream aorta. Unfortunately, no optimal standard treatment or technique to treat this disease exists. Total arch replacement with frozen elephant trunk technique plays an important role in treating acute type A aortic dissection. We aim to describe a modified elephant trunk technique and report its short-term outcomes. METHODS: From February 2018 to August 2019, 16 patients diagnosed with acute Stanford type A aortic dissection underwent surgery with the modified frozen elephant trunk technique at Xiamen Heart Center (male/female: 9/7; average age: 56.1 ± 7.6 years). All perioperative variables were recorded and analyzed. We measured the diameters of the ascending aorta, aortic arch, and descending aorta on the bifurcation of the pulmonary and abdominal aortas and compared the diameters at admission, before discharge, and 3 months after discharge. RESULTS: Fifteen patients (93.8%) had hypertension. The primary tears were located in the lesser curvature of the aortic arch and ascending aorta in 5 (31.3%) and 9 patients (56.3%), respectively, and no entry was found in 2 patients (12.5%). The dissection extended to the iliac artery and distal descending aorta in 14 (87.6%) and 2 patients (12.5%), respectively. The duration of cardiopulmonary bypass (CPB), cross-clamping, and antegrade cerebral perfusion were 215.8 ± 40.5, 140.8 ± 32.3, and 55.1 ± 15.2 min, respectively. Aortic valve repair was performed in 15 patients (93.8%). Bentall procedure was performed in one patient (6.3%). Another patient received coronary artery repair (6.3%). The diameters at all levels were greater on discharge than those on admission, except the aortic arch. After 3 months, the true lumen diameter distal to the frozen elephant trunk increased, indicating false lumen thrombosis and/or aortic remodeling. CONCLUSIONS: The modified frozen elephant trunk technique for acute Stanford type A aortic dissection is safe and feasible and could be used for organ malperfusion. Short-term outcomes are encouraging, but long-term outcomes require further investigation.

Relationship Between Fibrinogen to Albumin Ratio and Prognosis of Gastrointestinal Stromal Tumors: A Retrospective Cohort Study.

OBJECTIVE: The fibrinogen to albumin ratio (FAR) is an important parameter that reflects the coagulation state, systemic inflammation, and nutritional status of a patient and plays an essential role in tumor progression. Here, we evaluate the prognostic significance of FAR in gastrointestinal stromal tumor (GIST) patients that underwent radical surgery. METHODS: We retrospectively analyzed the data of 227 GIST patients that underwent radical surgery in Beijing Hospital from October 2004 to July 2018. We drew a curve of receiver operating characteristics to confirm the optimal critical values for hemoglobin (Hb), prognostic nutrition index (PNI), and FAR. Cox regression analysis and the Kaplan-Meier method were used to assess the prognostic factors. RESULTS: The FAR optimal critical value for postoperative recurrence-free survival (RFS) was 0.09. Many significant factors, including approach, the location and size of the tumor, mitotic index, risk classification, Hb levels, PNI, and recurrence, affect FAR. Multivariate analysis indicated that for patients with GISTs who underwent surgery, the tumor location (hazard ratio [HR]=3.393, 95% confidence interval [CI]: 1.539-7.479, P=0.002), mitotic index (HR=4.788, 95% CI: 1.836-12.486, P=0.001), tumor rupture (HR=10.954, 95% CI: 2.170-55.296, P=0.004), and FAR (HR=3.093, 95% CI: 1.303-7.339, P=0.010) were independent factors affecting RFS. Moreover, the FAR remained of prognostic significance for GIST stratified by subgroup analysis. CONCLUSION: Preoperative FAR is a reliable marker for evaluating the prognosis of GIST, the prognostic ability of FAR is significantly better than Hb and PNI.

Prognostic significance of preoperative plasma fibrinogen levels in primary gastrointestinal stromal tumours: a retrospective cohort study.

BACKGROUND: Improved prediction of prognosis for gastrointestinal stromal tumours (GISTs) has become increasingly important since the introduction of targeted therapy. Here, we aimed to evaluate the prognostic significance of preoperative plasma fibrinogen (Fib) levels in patients with primary GISTs and to analyse their correlations with clinicopathological characteristics. METHODS: A total of 201 previously untreated patients with primary GISTs who had undergone radical surgery at our institution between October 2004 and July 2018 were enrolled. The optimal cut-off value for Fib levels was calculated using time-dependent receiver-operating characteristic curve analysis. RFS, the primary endpoint, was calculated by the Kaplan-Meier method and compared by the log-rank test. Univariate and multivariate Cox regression models were calculated. RESULTS: High preoperative plasma Fib levels were detected as an independent adverse prognostic factor (p = 0.008, hazard ratio 3.136, 95% CI 1.356‒7.256). Furthermore, high preoperative plasma Fib levels also indicated a poor prognosis within the modified National Institutes of Health (mNIH) high-risk subgroup (p = 0.041). In addition, preoperative plasma Fib levels showed a positive correlation with several prognostic factors and even a linear relationship with tumour size (Spearman correlation coefficient [r] = 0.411, p < 0.001). CONCLUSIONS: Our results suggest that high preoperative plasma Fib levels may indicate a poor prognosis in patients with primary GISTs. As a cost-effective biomarker, preoperative assessment of plasma Fib levels may help to further risk stratify patients with mNIH high-risk GISTs and instruct the application of targeted therapy.

Construction of a Competitive Endogenous RNA Network and Identification of Potential Regulatory Axis in Gastric Cancer.

Background: Increasing studies has found that long non-coding RNAs (lncRNAs) play critical roles in carcinogenesis, but the underlying mechanisms remain unclear. The aim of this study is to construct a competitive endogenous RNA (ceRNA) network and to identify potential regulatory axis in gastric cancer (GC). Methods: Differentially expressed (DE) mRNAs, miRNAs, and lncRNAs were obtained by analyzing the RNA expression profiles of stomach adenocarcinoma (STAD) retrieved from The Cancer Genome Atlas (TCGA) database. The lncRNA-miRNA-mRNA regulatory networks of GC were constructed by comprehensive bioinformatics methods including functional annotation, RNA-RNA interactomes prediction, correlation analysis, and survival analysis. The interactions and correlations among ceRNAs were validated by experiments on cancer tissues and cell lines. Results: A total of 41 lncRNAs, 9 miRNAs, and 10 mRNAs were identified and selected to establish the ceRNA regulatory network of GC. Several ceRNA regulatory axes, which consist of 18 lncRNAs, 4 miRNAs, and 6 mRNAs, were obtained from the network. A potential ADAMTS9-AS2/miR-372/CADM2 axis which perfectly conformed to the ceRNA theory was further analyzed. qRT-PCR showed that ADAMTS9-AS2 knockdown remarkably increased miR-372 expression but reduced CADM2 expression, whereas ADAMTS9-AS2 overexpression had the opposite effects. Dual luciferase reporter assay indicated that miR-372 could bound to the ADAMTS9-AS2 and the 3'UTR of CADM2. Conclusion: The constructed novel ceRNA network and the potential regulatory axes might provide a novel approach of the exploring the potential mechanisms of development in GC. The ADAMTS9-AS2/miR-372/CADM2 could act as a promising target for GC treatment.

EXOSC5 as a Novel Prognostic Marker Promotes Proliferation of Colorectal Cancer via Activating the ERK and AKT Pathways.

Background and Objective: Exosome component 5 (EXOSC5) is a novel cancer-related gene that is aberrantly expressed in various malignances. However, the molecular mechanism and biological role of EXOSC5 have not been explored in colorectal cancer (CRC). In this study, we investigated the functions and mechanisms by which EXOSC5 promotes the progression of CRC. Methods: EXOSC5 expressions in CRC cell lines and paired CRC and adjacent normal tissues were measured via quantitative real-time PCR (qRT-PCR), Western blot and immunohistochemistry (IHC). In vitro experiments including colony formation, Cell Counting Kit-8 (CCK-8), and flow cytometry and in vivo tumorigenesis assay were performed to explore the effects of EXOSC5 on growth of CRC. The impacts of EXOSC5 on ERK and Akt signaling pathways were measured by Western blot. Results: The mRNA and protein expression levels of EXOSC5 were up-regulated in CRC as compared to adjacent normal tissues. IHC analysis indicated that high EXOSC5 level was positively associated with poor prognosis. EXOSC5 overexpression facilitated the growth of CRC cells, while EXOSC5 knockdown led to decreased proliferation, G1/S phase transition arrest. The oncogenic functions of EXOSC5 were associated with activation of the ERK and Akt pathways in CRC. Conclusion: EXOSC5 is overexpressed in CRC and promotes CRC growth partly through activation of ERK and Akt signaling pathways. Accordingly, EXOSC5 may be a novel oncogene, and acts as a therapeutic target, or prognostic factor for CRC.

Carboxypeptidase A4 promotes cell growth via activating STAT3 and ERK signaling pathways and predicts a poor prognosis in colorectal cancer.

Carboxypeptidase A4 (CPA4) is a novel cancer-related gene that is aberrantly expressed in various malignant tumors. However, the roles and mechanisms of CPA4 have not been explored in colorectal cancer (CRC). In this study, we investigated the functions and mechanisms by which CPA4 promotes CRC progression. Quantitative real-time PCR (qRT-PCR) and western blot showed that CPA4 mRNA and CPA4 protein levels were up-regulated in CRC compared to levels in adjacent normal tissue. Immunohistochemistry (IHC) results indicating high CPA4 levels were positively associated with poor prognoses. In addition, Cell Counting Kit-8 (CCK-8), colony formation, flow cytometry, and transwell assays demonstrated that CPA4 overexpression facilitated the growth of CRC cells, whereas CPA4 knockdown resulted in decreased proliferation, G1/S phase transition arrest, and apoptosis. Subcutaneous tumorigenesis was performed in nude mice to confirm the tumor-promoting effects of CPA4 in vivo. Western blot revealed that activation of the STAT3 and ERK pathways is one of the oncogenic functions of CPA4 in CRC. Accordingly, CPA4 promotes CRC cell growth via activating the STAT3 and ERK pathways and may be a prognostic factor or therapeutic target for CRC.

Identification and development of long non-coding RNA-associated regulatory network in colorectal cancer.

Colorectal cancer (CRC) is one of the leading causes of cancer-associated death globally. Long non-coding RNAs (lncRNAs) have been identified as micro RNA (miRNA) sponges in a competing endogenous RNA (ceRNA) network and are involved in the regulation of mRNA expression. This study aims to construct a lncRNA-associated ceRNA network and investigate the prognostic biomarkers in CRC. A total of 38 differentially expressed (DE) lncRNAs, 23 DEmiRNAs and 27 DEmRNAs were identified by analysing the expression profiles of CRC obtained from The Cancer Genome Atlas (TCGA). These RNAs were chosen to develop a ceRNA regulatory network of CRC, which comprised 125 edges. Survival analysis showed that four lncRNAs, six miRNAs and five mRNAs were significantly associated with overall survival. A potential regulatory axis of ADAMTS9-AS2/miR-32/PHLPP2 was identified from the network. Experimental validation was performed using clinical samples by quantitative real-time PCR (qRT-PCR), which showed that expression of the genes in the axis was associated with clinicopathological features and the correlation among them perfectly conformed to the 'ceRNA theory'. Overexpression of ADAMTS9-AS2 in colon cancer cell lines significantly inhibited the miR-32 expression and promoted PHLPP2 expression, while ADAMTS9-AS2 knockdown had the opposite effects. The constructed novel ceRNA network may provide a comprehensive understanding of the mechanisms of CRC carcinogenesis. The ADAMTS9-AS2/miR-32/PHLPP2 regulatory axis may serve as a potential therapeutic target for CRC.