Emerging roles of long noncoding RNAs in chemoresistance of pancreatic cancer.

Pancreatic cancer is one of the most common causes of cancer death in the world due to the lack of early symptoms, metastasis occurrence and chemoresistance. Therefore, early diagnosis by detection of biomarkers, blockade of metastasis, and overcoming chemoresistance are the effective strategies to improve the survival of pancreatic cancer patients. Accumulating evidence has revealed that long noncoding RNA (lncRNA) and circular RNAs (circRNAs) play essential roles in modulating chemosensitivity in pancreatic cancer. In this review article, we will summarize the role of lncRNAs in drug resistance of pancreatic cancer cells, including HOTTIP, HOTAIR, PVT1, linc-ROR, GAS5, UCA1, DYNC2H1-4, MEG3, TUG1, HOST2, HCP5, SLC7A11-AS1 and CASC2. We also highlight the function of circRNAs, such as circHIPK3 and circ_0000284, in regulation of drug sensitivity of pancreatic cancer cells. Moreover, we describe a number of compounds, including curcumin, genistein, resveratrol, quercetin, and salinomycin, which may modulate the expression of lncRNAs and enhance chemosensitivity in pancreatic cancers. Therefore, targeting specific lncRNAs and cicrRNAs could contribute to reverse chemoresistance of pancreatic cancer cells. We hope this review might stimulate the studies of lncRNAs and cicrRNAs, and develop the new therapeutic strategy via modulating these noncoding RNAs to promote chemosensitivity of pancreatic cancer cells.

Investigation of Metabolic and Inflammatory Disorder in the Aging FGF21 Knockout Mouse.

Aging is a physiological condition accomplished with persistent low-grade inflammation and metabolic disorders. FGF21 has been reported to act as a potent longevity determinant, involving inflammatory response and energy metabolism. In this study, we engineered aging FGF21 knockout mice of 36-40 weeks and observed that FGF21 deficiency manifests a spontaneous inflammatory response of lung and abnormal accumulation of lipids in liver. On one hand, inflamed state in lungs and increased circulating inflammatory cytokines were found in FGF21 knockout mice of 36-40 weeks. To evaluate the ability of FGF21 to suppress inflammation, a subsequent study found that FGF21 knockout aggravated LPS-induced pulmonary exudation and inflammatory infiltration in mice, while exogenous administration of FGF21 reversed these malignant phenotypes by enhancing microvascular endothelial junction. On the other hand, FGF21 knockout induces fatty liver in aging mice, characterized by excessive accumulation of triglycerides within hepatocytes. Further quantitative metabolomics and lipidomics analysis revealed perturbed metabolic profile in liver lacking FGF21, including disrupted glucose and lipids metabolism, glycerophospholipid metabolism, and amino acid metabolism. Taken together, this investigation reveals the protective role of FGF21 during aging by weakening the inflammatory response and balancing energy metabolism.

Transfer RNA-derived small RNAs (tsRNAs) sequencing revealed a differential expression landscape of tsRNAs between glioblastoma and low-grade glioma.

BACKGROUND: Glioblastomas (GBMs) are the most lethal brain cancer with a median survival rate of fewer than 15 months. Both clinical and biological features of GBMs are largely different from those of low-grade gliomas (LGs), but the reasons for this intratumoral heterogeneity are not entirely clear. Transfer RNA (tRNA)-derived small RNAs (tsRNAs) were derived from tRNA precursors and mature tRNA, referring to the specific cleavage of tRNAs by dicer and angiogenin (ANG) in particular cells or tissues or under certain conditions such as stress and hypoxia. With the characteristics of wide expression and high stability, tsRNAs could be used as favorable biomarkers for diagnosis, treatment, and prognosis prediction of the tumor, viral infection, neurological as well as other systemic diseases. In this study, we have compared the differential expressed tsRNAs between GBMs and LGs, so as to investigate the possible pathogenic molecules and provide references for discovering novel nucleic acid drugs in future studies. METHODS: Fresh tumor tissues of patients that were diagnosed as GBMs (4 cases) and LGs (5 cases) at the First Affiliated Hospital of Wenzhou Medical University from 2019.05 to 2021.01 were collected. The tsRNAs' levels were analyzed and compared through high-throughput sequencing, candidate tsRNAs were chosen according to the expression level, and the expression of the candidate tsRNAs was validated through qPCR. Finally, the potential targets were imputed using the Miranda and TargetScan databases, and possible biological functions of the differentially expressed (DE) tsRNAs' targets were enriched based on GO and KEGG databases. RESULTS: A total of 4 GBMs and 5 LGs patients were enrolled in the current study. High-throughput sequencing showed that 186 tsRNAs were expressed in two groups, over them, 43 tsRNAs were unique to GBMs, and 24 tsRNAs were unique to LGs. A total of 9 tsRNAs were selected as candidate tsRNAs according to the tsRNA expression level, among which 6 tsRNAs were highly expressed in GBMs and 3 tsRNAs were low expressed in GBMs. qPCR verification further demonstrated that 5 tsRNAs were significantly up-regulated and 1 tsRNA was significantly down-regulated in GBMs: tRF-1-32-chrM.Lys-TTT (p=0.00118), tiRNA-1-33-Gly-GCC-1 (p=0.00203), tiRNA-1-33-Gly-CCC-1 (p=0.00460), tRF-1-31-His-GTG-1 (p=0.00819), tiRNA-1-33-Gly-GCC-2-M3 (p=0.01032), and tiRNA-1-34-Lys-CTT-1-M2 (p=0.03569). Enrichment analysis of the qPCR verified DE tsRNAs showed that the 5 up-regulated tsRNAs seemed to be associated with axon guidance, pluripotent stem cells regulation, nucleotide excision repair, Hippo signaling pathway, and cancer-related pathways, while the down-regulated tsRNA (tRF-1-32-chrM.Lys-TTT) was associated with oocyte meiosis and renin secretion. CONCLUSION: The tsRNAs were differentially expressed in tumor tissues between GBMs and LGs, especially tRF-1-32-chrM.Lys-TTT, tiRNA-1-33-Gly-GCC-1, tiRNA-1-33-Gly-CCC-1, tRF-1-31-His-GTG-1, tiRNA-1-33-Gly-GCC-2-M3, and tiRNA-1-34-Lys-CTT-1-M2. These tsRNAs seemed to be associated with nucleotide excision repair, Hippo signaling, and cancer-related pathways. This may be the main reason for the differences in clinical characteristics between GBMs and LGs, which may provide a certain theoretical basis for further functional research and development of related nucleic acid drugs. CONCLUSION: The tsRNAs were differentially expressed in tumor tissues between GBMs and LGs, especially tRF-1-32-chrM.Lys-TTT, tiRNA-1-33-Gly-GCC-1, tiRNA-1-33-Gly-CCC-1, tRF-1-31-His-GTG-1, tiRNA-1-33-Gly-GCC-2-M3, and tiRNA-1-34-Lys-CTT-1-M2. These tsRNAs seemed to be associated with nucleotide excision repair, Hippo signaling, and cancer-related pathways. This may be the main reason for the differences in clinical characteristics between GBMs and LGs, which may provide a certain theoretical basis for further functional research and development of related nucleic acid drugs.

ASAP1 activates the IQGAP1/CDC42 pathway to promote tumor progression and chemotherapy resistance in gastric cancer.

Abnormal expression and remodeling of cytoskeletal regulatory proteins are important mechanisms for tumor development and chemotherapy resistance. This study systematically analyzed the relationship between differential expression of cytoskeleton genes and prognosis in gastric cancer (GC). We found the Arf GTP-activating protein ASAP1 plays a key role in cytoskeletal remodeling and prognosis in GC patients. Here we analyzed the expression level of ASAP1 in tissue microarrays carrying 564 GC tissues by immunohistochemistry. The results showed that ASAP1 expression was upregulated in GC cells and can be served as a predictor of poor prognosis. Moreover, ASAP1 promoted the proliferation, migration, and invasion of GC cells both in vitro and in vivo. We also demonstrated that ASAP1 inhibited the ubiquitin-mediated degradation of IQGAP1 and thus enhanced the activity of CDC42. The activated CDC42 upregulated the EGFR-MAPK pathway, thereby promoting the resistance to chemotherapy in GC. Taken together, our results revealed a novel mechanism by which ASAP1 acts in the progression and chemotherapy resistance in GC. This may provide an additional treatment option for patients with GC.

Necroptosis-related lncRNAs: Combination of bulk and single-cell sequencing reveals immune landscape alteration and a novel prognosis stratification approach in lung adenocarcinoma.

Necroptosis, which is recently recognized as a form of programmed cell death, plays a critical role in cancer biology, including tumorigenesis and cancer immunology. It was recognized not only to defend against tumor progression by suppressing adaptive immune responses but also to promote tumorigenesis and cancer metastasis after recruiting inflammatory responses. Thus the crucial role of necrosis in tumorigenesis has attracted increasing attention. Due to the heterogeneity of the tumor immune microenvironment (TIME) in lung adenocarcinoma (LUAD), the prognosis and the response to immunotherapy vary distinctly across patients, underscoring the need for a stratification algorithm for clinical practice. Although previous studies have formulated the crucial role of lncRNAs in tumorigenicity, the relationship between necroptosis-related lncRNAs, TIME, and the prognosis of patients with LUAD was still elusive. In the current study, a robust and novel prognostic stratification model based on Necroptosis-related LncRNA Risk Scoring (NecroLRS) and clinicopathological parameters was constructed and systemically validated in both internal and external validation cohorts. The expression profile of four key lncRNAs was further validated by qRT-PCR in 4 human LUAD cell lines. And a novel immune landscape alteration was observed between NecroLRS-High and -Low patients. To further elucidate the mechanism of necroptosis in the prognosis of LUAD from a single-cell perspective, a novel stratification algorithm based on K-means clustering was introduced to extract both malignant and NecroLRS-High subsets from epithelial cells. And the necroptosis-related immune infiltration landscape and developmental trajectory were investigated respectively. Critically, NecroLRS was found to be positively correlated with neutrophil enrichment, inflammatory immune response, and malignant phenotypes of LUAD. In addition, novel ligand-receptor pairs between NecroLRS-High cells and other immunocytes were investigated and optimal therapeutic compounds were screened to provide potential targets for future studies. Taken together, our findings reveal emerging mechanisms of necroptosis-induced immune microenvironment alteration on the deteriorative prognosis and may contribute to improved prognosis and individualized precision therapy for patients with LUAD.

Deep Learning Analysis Using 18F-FDG PET/CT to Predict Occult Lymph Node Metastasis in Patients With Clinical N0 Lung Adenocarcinoma.

Introduction: The aim of this work was to determine the feasibility of using a deep learning approach to predict occult lymph node metastasis (OLM) based on preoperative FDG-PET/CT images in patients with clinical node-negative (cN0) lung adenocarcinoma. Materials and Methods: Dataset 1 (for training and internal validation) included 376 consecutive patients with cN0 lung adenocarcinoma from our hospital between May 2012 and May 2021. Dataset 2 (for prospective test) used 58 consecutive patients with cN0 lung adenocarcinoma from June 2021 to February 2022 at the same center. Three deep learning models: PET alone, CT alone, and combined model, were developed for the prediction of OLM. The performance of the models was evaluated on internal validation and prospective test in terms of accuracy, sensitivity, specificity, and areas under the receiver operating characteristic curve (AUCs). Results: The combined model incorporating PET and CT showed the best performance, achieved an AUC of 0.81 [95% confidence interval (CI): 0.61, 1.00] in the prediction of OLM in internal validation set (n = 60) and an AUC of 0.87 (95% CI: 0.75, 0.99) in the prospective test set (n = 58). The model achieved 87.50% sensitivity, 80.00% specificity, and 81.00% accuracy in the internal validation set and achieved 75.00% sensitivity, 88.46% specificity, and 86.60% accuracy in the prospective test set. Conclusion: This study presented a deep learning approach to enable the prediction of occult nodal involvement based on the PET/CT images before surgery in cN0 lung adenocarcinoma, which would help clinicians select patients who would be suitable for sublobar resection.

Incidence, Risk Factors and Prognosis of T4a Gastric Cancer: A Population-Based Study.

Background: T4a gastric cancer (GC) is a subtype of advanced GC (AGC), which urgently needs a comprehensive grade method for better treatment strategy choosing. The purpose of this study was to develop two nomograms for predicting the prognosis of patients with T4a GC. Methods: A total of 1,129 patients diagnosed as T4a GC between 2010 and 2015 were extracted from the Surveillance, Epidemiology, and End Result (SEER) program database. Univariate and multivariate Cox analyses were performed to explore the independent predictors and to establish nomogram for overall survival (OS) of the patients, whereas competing risk analyses were performed to find the independent predictors and to establish nomogram for cancer-specific survival (CSS) of the patients. The area under the curve (AUC), calibration curve, decision curve analysis (DCA), and Kaplan-Meier analysis were performed to evaluate the nomograms. Results: Older age, larger tumor size, black race, signet ring cell carcinoma (SRCC), more lymph node involvement, the absence of surgery, the absence of radiotherapy, and the absence of chemotherapy were identified as independent prognostic factors for both OS and CSS. In the training cohort, the AUCs of the OS nomogram were 0.760, 0.743, and 0.723 for 1-, 3-, and 5-year OS, whereas the AUCs of the CSS nomogram were 0.724, 0.703, and 0.713 for 1-, 3-, and 5-year CSS, respectively. The calibration curve and DCA indicated that both nomograms can effectively predict OS and CSS, respectively. The abovementioned results were also confirmed in the validation cohort. Stratification of the patients into high- and low-risk groups highlighted the differences in prognosis between the two groups both in training and in validation cohorts. Conclusions: Age, tumor size, race, histologic type, N stage, surgery status, radiotherapy, and chemotherapy were confirmed as independent prognostic factors for both OS and CSS in patients with T4a GC. Two nomograms based on the abovementioned variables were constructed to provide more accurate individual survival predictions for them.

Exploring the significance of novel immune-related gene signatures in the prognosis and immune features of pancreatic adenocarcinoma.

BACKGROUND: Immune-related genes (IRGs) are associated with the prognosis of different cancers and are helpful for the diagnosis and management of systematic treatment for cancer patients. However, there have been a few corresponding studies in pancreatic adenocarcinoma (PAAD). METHODS: The data of PAAD patients were obtained from the TCGA, GEO, and ICGC databases. Additionally, the expression profiles of the normal pancreas from the GTEx database were used to screen differentially expressed immune-related genes (DEIRGs). Cox regression analyses were used to explore overall survival (OS)- and progression-free survival (PFS)-related DEIRGs and to establish two nomograms for PAAD prognosis. Finally, transcription factor (TF), immune infiltration, and unsupervised consensus analyses were performed to understand the potential mechanisms. RESULTS: An OS-prognostic signature based on seven DEIRGs and a PFS-prognostic signature based on seven DEIRGs were generated, and their robust prognostic ability was confirmed by ROC curves (OS: 0.736 ~ 0.774, PFS: 0.732 ~ 0.840). According to the risk score, the OS and PFS of the high-risk group were poorer than those of the low-risk group in the training set and four external validation sets. In addition, two nomograms based on the signatures and clinical variables also showed excellent discrimination. And two hub regulatory pathways were successfully validated in several independent datasets. Discernable patterns of DEIRGs in unsupervised consensus analysis showed that patients with low expression of immune checkpoints had a favorable prognosis. CONCLUSION: Two DEIRG-based signatures can be used as independent tools for the prognostic prediction of PAAD and to provide potential novel immunotherapy targets.

Risk Factors, Prognostic Factors, and Nomograms for Distant Metastasis in Patients With Newly Diagnosed Osteosarcoma: A Population-Based Study.

Background: Osteosarcoma is the most common bone cancer, mainly occurring in children and adolescents, among which distant metastasis (DM) still leads to a poor prognosis. Although nomogram has recently been used in tumor areas, there are no studies focused on diagnostic and prognostic evaluation of DM in primary osteosarcoma patients. Methods: The data of osteosarcoma patients diagnosed between 2004 and 2015 were extracted from the Surveillance, Epidemiology, and End Results (SEER) database. Univariate and multivariate logistic regression analyses were used to identify independent risk factors for DM in osteosarcoma patients, and univariate and multivariate Cox proportional hazards regression analyses were used to determine independent prognostic factors of osteosarcoma patients with DM. We then established two novel nomograms and the results were evaluated by receiver operating characteristic (ROC) curves, calibration curves, and decision curve analysis (DCA). Result: A total of 1,657 patients with osteosarcoma were included, and 267 patients (16.11%) had DM at the time of diagnosis. The independent risk factors for DM in patients with osteosarcoma include age, grade, T stage, and N stage. The independent prognostic factors for osteosarcoma patients with DM are age, chemotherapy and surgery. The results of ROC curves, calibration, DCA, and Kaplan-Meier (K-M) survival curves in the training, validation, and expanded testing sets, confirmed that two nomograms can precisely predict occurrence and prognosis of DM in osteosarcoma patients. Conclusion: Two nomograms are expected to be effective tools for predicting the risk of DM for osteosarcoma patients and personalized prognosis prediction for patients with DM, which may benefit clinical decision-making.

Downregulated miR­29a promotes B cell overactivation by upregulating Crk­like protein in systemic lupus erythematosus.

Systemic lupus erythematosus (SLE) is an autoimmune disorder; however, the pathogenesis is not fully understood. Accumulating evidence suggested an important role of microRNAs (miRNA/miR) in autoimmunity. The present study aimed therefore to determine the miRNA expression patterns in the B cells from the peripheral blood of 66 patients with SLE and 10 healthy controls (HCs) by using an Affymetrix GeneChip® miRNA 2.0 array. In addition, next­generation sequencing was used to obtain the peripheral blood mononuclear cell (PBMC) miRNA profiles from three patients with SLE and three HCs. Candidate miRNAs that were considered to contribute to the pathogenesis of SLE were obtained based on the intersection of miRNA profiles. The analysis revealed a significant downregulation in miR­29a expression levels in B cells from patients with SLE, which was subsequently verified using reverse transcription­quantitative PCR. Based on these results, the expression pattern of miR­29a in SLE was further investigated and its role in the hyperactivity of B cells was determined. miR­29a inhibitors and mimics were transfected into PBMCs obtained from HCs and patients with SLE, and an ELISA was used to demonstrate that miR­29a inhibition increased the production of IgG. Bioinformatics analysis predicted Crk­like protein (CRKL) as a target gene of miR­29a in patients with SLE. Therefore, CRKL expression levels were compared between patients with SLE and HCs by using western blotting, and its direct transcriptional regulation by miR­29a was determined using a dual­luciferase reporter assay. Low expression levels of miR­29a were revealed to upregulate the expression levels of CRKL in B cells, and the protein expression levels of CRKL in patients with SLE were significantly upregulated compared with the HCs. In conclusion, the results from the present study suggested that miR­29a may affect IgG antibody secretion in B cells by regulating CRKL, thereby contributing to the development and progression of SLE, which offers a novel candidate target for treatment.

Progress of Research on Exosomes in the Protection Against Ischemic Brain Injury.

Exosomes, as a type of extracellular vesicle (EV), are lipid bilayer vesicles 20-100 nm in diameter that can cross the blood-brain barrier. Exosomes are important transport vesicles in the human body that participate in many conduction pathways and play an important physiological role. Because of their high biocompatibility and low immunogenicity and toxicity, exosomes have attracted increasing attention as an attractive drug delivery system. This article reviews the relevant studies that have shown that exosomes play an important role in protective mechanisms against ischemic brain injury.