High patatin like phospholipase domain containing 8 expression as a biomarker for poor prognosis of colorectal cancer.

BACKGROUND: Patatin like phospholipase domain containing 8 (PNPLA8) has been shown to play a significant role in various cancer entities. Previous studies have focused on its roles as an antioxidant and in lipid peroxidation. However, the role of PNPLA8 in colorectal cancer (CRC) progression is unclear. AIM: To explore the prognostic effects of PNPLA8 expression in CRC. METHODS: A retrospective cohort containing 751 consecutive CRC patients was enrolled. PNPLA8 expression in tumor samples was evaluated by immunohistochemistry staining and semi-quantitated with immunoreactive scores. CRC patients were divided into high and low PNPLA8 expression groups based on the cut-off values, which were calculated by X-tile software. The prognostic value of PNPLA8 was identified using univariate and multivariate Cox regression analysis. The overall survival (OS) rates of CRC patients in the study cohort were compared with Kaplan-Meier analysis and Log-rank test. RESULTS: PNPLA8 expression was significantly associated with distant metastases in our cohort (P = 0.048). CRC patients with high PNPLA8 expression indicated poor OS (median OS = 35.3, P = 0.005). CRC patients with a higher PNPLA8 expression at either stage I and II or stage III and IV had statistically significant shorter OS. For patients with left-sided colon and rectal cancer, the survival curves of two PNPLA8-expression groups showed statistically significant differences. Multivariate analysis also confirmed that high PNPLA8 expression was an independent prognostic factor for overall survival (hazard ratio HR = 1.328, 95%CI: 1.016-1.734, P = 0.038). CONCLUSION: PNPLA8 is a novel independent prognostic factor for CRC. These findings suggest that PNPLA8 is a potential target in clinical CRC management.

Assessing Seasonal Effects on Identification of Cultivation Methods of Short-Growth Cycle Brassica chinensis L. Using IRMS and NIRS.

Seasonal (temporal) variations can influence the δ13C, δ2H, δ18O, and δ15N values and nutrient composition of organic (ORG), green (GRE), and conventional (CON) vegetables with a short growth cycle. Stable isotope ratio mass spectrometry (IRMS) and near-infrared spectroscopy (NIRS) combined with the partial least squares-discriminant analysis (PLS-DA) method were used to investigate seasonal effects on the identification of ORG, GRE, and CON Brassica chinensis L. samples (BCs). The results showed that δ15N values had significant differences among the three cultivation methods and that δ13C, δ2H, and δ18O values were significantly higher in winter and spring and lower in summer. The NIR spectra were relatively clustered across seasons. Neither IRMS-PLS-DA nor NIRS-PLS-DA could effectively identify all BC cultivation methods due to seasonal effects, while IRMS-NIRS-PLS-DA combined with Norris smoothing and derivative pretreatment had better predictive abilities, with an 89.80% accuracy for ORG and BCs, 88.89% for ORG and GRE BCs, and 75.00% for GRE and CON BCs. The IRMS-NIRS-PLS-DA provided an effective and robust method to identify BC cultivation methods, integrating multi-seasonal differences.

Siglec9 + tumor-associated macrophages predict prognosis and therapeutic vulnerability in patients with colon cancer.

BACKGROUND: Siglec9 has been identified as an immune checkpoint molecule on tumor-associated macrophages (TAMs). Nevertheless, the expression profile and clinical significance of Siglec9 + TAMs in colon cancer (CC) are still not fully understood. METHODS: Two clinical cohorts from distinct medical centers were retrospectively enrolled. Immunohistochemistry and immunofluorescence were conducted to evaluate the infiltration of immune cells. Single-cell RNA sequencing and flow cytometry were utilized to identify the impact of Siglec9 + TAMs on the tumor immune environment, which was subsequently validated through bioinformatics analysis of the TCGA database. Prognosis and the benefit of adjuvant chemotherapy (ACT) were also evaluated using Cox regression analysis and the Kaplan-Meier method. RESULTS: High infiltration of Siglec9 + TAMs was associated with worse prognosis and better benefit from 6-month ACT. Siglec9 + TAMs contributed to immunoevasion by promoting the infiltration of immunosuppressive cells and the dysfunction process of CD8 + T cells. Additionally, high infiltration of Siglec9 + TAMs was associated with the mesenchymal-featured subtype and overexpression of the VEGF signaling pathway, which was validated by the strongest communication between Siglec9 + TAMs and vascular endothelial cells. CONCLUSIONS: Siglec9 + TAMs may serve as a biomarker for prognosis and response to ACT in CC. Furthermore, the immunoevasive contexture and angiogenesis stimulated by Siglec9 + TAMs suggest potential treatment combinations for CC patients.

Protein S-palmitoylation modification: implications in tumor and tumor immune microenvironment.

Protein S-palmitoylation is a reversible post-translational lipid modification that involves the addition of a 16-carbon palmitoyl group to a protein cysteine residue via a thioester linkage. This modification plays a crucial role in the regulation protein localization, accumulation, secretion, stability, and function. Dysregulation of protein S-palmitoylation can disrupt cellular pathways and contribute to the development of various diseases, particularly cancers. Aberrant S-palmitoylation has been extensively studied and proven to be involved in tumor initiation and growth, metastasis, and apoptosis. In addition, emerging evidence suggests that protein S-palmitoylation may also have a potential role in immune modulation. Therefore, a comprehensive understanding of the regulatory mechanisms of S-palmitoylation in tumor cells and the tumor immune microenvironment is essential to improve our understanding of this process. In this review, we summarize the recent progress of S-palmitoylation in tumors and the tumor immune microenvironment, focusing on the S-palmitoylation modification of various proteins. Furthermore, we propose new ideas for immunotherapeutic strategies through S-palmitoylation intervention.

Real-world clinical outcomes of oral anticoagulants among Japanese patients with atrial fibrillation and concomitant coronary artery disease.

Background: Stroke prevention is complicated in patients with atrial fibrillation (AF) and coronary artery disease (CAD). We compared the risk of major bleeding among Japanese patients with AF and CAD commencing warfarin, dabigatran, or rivaroxaban. Methods: This study included adults with AF and CAD who were newly prescribed the non-vitamin K antagonist oral anticoagulants (NOACs) dabigatran or rivaroxaban, or warfarin, and registered between 18 April 2011 through 31 December 2020 in the Medical Data Vision hospital-based clinical database. The primary outcome was major bleeding, and the secondary outcome was a composite of stroke, systemic embolism, myocardial infarction, all-cause inpatient mortality, major bleeding, major gastrointestinal bleeding, and intracerebral hemorrhage. Cox proportional hazard models with stabilized inverse probability treatment weighting were used to estimate hazard ratios (HRs) with 95 % CIs via a two-step approach; first between warfarin and each NOAC, then between NOACs if sample size conditions were met. Results: Dabigatran, rivaroxaban, and warfarin groups included 6712, 20,329, and 12,316 patients, respectively. Major bleeding risk was lower in NOACs versus warfarin (dabigatran: HR 0.50, 95 % CI: 0.40-0.62; rivaroxaban: HR 0.78, 95 % CI: 0.69-0.90); this risk was lower with dabigatran compared with rivaroxaban (HR 0.64, 95 % CI: 0.51─0.79). Net clinical benefit was superior to warfarin in both NOACs (dabigatran: HR 0.78, 95 % CI: 0.71-0.85; rivaroxaban: HR 0.83, 95 % CI: 0.78-0.88). Conclusions: Among real-world Japanese patients with AF and CAD, NOACs were associated with better clinical outcomes than warfarin. Treatment with dabigatran had a lower risk of major bleeding than rivaroxaban.Clinical trial registration: NCT05051904 (ClinicalTrials.gov).

Impact of Surgical Management for Relapse After Conversion Hepatectomy for Initially Unresectable Colorectal Liver Metastasis: A Retrospective Cohort Study.

BACKGROUND: For patients with initially unresectable colorectal liver metastasis (IU-CRLM) receiving conversion therapy, disease relapse after conversion hepatectomy is common. However, few studies have focused on the assessment and management of relapse following conversion hepatectomy for IU-CRLM. METHODS: In the retrospective cohort study, 255 patients with IU-CRLM received conversion therapy and underwent subsequent R0 resection. The treatment effects of repeated liver-directed treatment (RLDT) versus non-RLDT for liver relapse were examined. Survival analysis was evaluated with the use of Cox proportional hazards methods. The importance of RLDT was further confirmed in the propensity score matching (PSM) and subgroup analyses. RESULTS: The 5-year overall survival (OS) rate after conversion hepatectomy was 34.9%. Liver relapse was observed in 208 patients. Of these patients, 106 underwent RLDT (65 underwent repeated hepatectomy and the remainder underwent ablation treatment), while 102 received only palliative chemotherapy. The relapse patients who underwent RLDT had a significantly longer OS than those who did not (hazard ratio (HR): 0.382, 95% CI: 0.259-0.563; P<0.001). In a multivariable analysis, RLDT was independently associated to prolonged survival (HR: 0.309, 95%CI: 0.181-0.529; P<0.001). In the PSM and subgroup analyses, RLDT consistently showed evidence of prolonging OS significantly. CONCLUSION: For IU-CRLM patients with liver relapse following conversion hepatectomy, the RLDT is essential for cure and prolonged survival. To avoid missing the opportunity for RLDT, intensive disease surveillance should be proposed.

Anatomical resection improves relapse-free survival in colorectal liver metastases in patients with KRAS/NRAS/BRAF mutations or right-sided colon cancer: a retrospective cohort study.

BACKGROUND: The type of liver resection (anatomical resection, AR or non-anatomical resection, NAR) for colorectal liver metastases (CRLM) is subject to debate. The debate may persist because some prognostic factors, associated with aggressive tumor biological behavior, have been overlooked. OBJECTIVE: Our study aimed to investigate the characteristics of patients who would benefit more from anatomical resection for CRLM. METHODS: Seven hundred twenty-nine patients who underwent hepatic resection of CRLM were retrospectively collected from June 2012 to May 2019. Treatment effects between AR and NAR were compared in full subgroup analyses. Tumor relapse-free survival (RFS) was evaluated by a stratified log-rank test and summarized with the use of Kaplan-Meier and Cox proportional hazards methods. RESULTS: Among 729 patients, 235 (32.2%) underwent AR and 494 (67.8%) underwent NAR. We showed favorable trends in RFS for AR compared with NAR in the patients with KRAS/NRAS/BRAF mutation (interaction P <0.001) or right-sidedness (interaction P <0.05). Patients who underwent AR had a markedly improved RFS compared with NAR in the cohorts of RAS/NRAS/BRAF mutation (median RFS 23.2 vs. 11.1 months, P <0.001) or right-sidedness (median RFS 31.6 vs. 11.5 months, P <0.001); upon the multivariable analyses, AR [gene mutation: hazard ratio (HR)=0.506, 95% CI=0.371-0.690, P <0.001; right-sidedness: HR=0.426, 95% CI=0.261-0.695, P =0.001) remained prognostic independently. In contrast, patients who underwent AR had a similar RFS compared with those who underwent NAR, in the cohorts of patients with gene wild-type tumors (median RFS 20.5 vs. 21.6 months, P =0.333). or left-sidedness (median RFS 15.8 vs. 19.5 months, P =0.294). CONCLUSIONS: CRLM patients with gene mutation or right-sidedness can benefit more from AR rather than from NAR.

Plasma proteomic profiling discovers molecular features associated with upper tract urothelial carcinoma.

Upper tract urothelial carcinoma (UTUC) is often diagnosed late and exhibits poor prognosis. Limited data are available on potential non-invasive biomarkers for disease monitoring. Here, we investigate the proteomic profile of plasma in 362 UTUC patients and 239 healthy controls. We present an integrated tissue-plasma proteomic approach to infer the signature proteins for identifying patients with muscle-invasive UTUC. We discover a protein panel that reflects lymph node metastasis, which is of interest in identifying UTUC patients with high risk and poor prognosis. We also identify a ten-protein classifier and establish a progression clock predicting progression-free survival of UTUC patients. Finally, we further validate the signature proteins by parallel reaction monitoring assay in an independent cohort. Collectively, this study portrays the plasma proteomic landscape of a UTUC cohort and provides a valuable resource for further biological and diagnostic research in UTUC.

Effects of Thiamethoxam and Fenvalerate Residue Levels on Light-Stable Isotopes of Leafy Vegetables.

Accurate identification of the rational and standardized use of pesticides is important for the sustainable development of agriculture while maintaining a high quality. The insecticides thiamethoxam and fenvalerate and the vegetables spinach, cabbage, and lettuce were used here as study objects. Descriptive analysis and primary reaction kinetic equations were used to analyze the changes in metabolic residues of the two insecticides after different numbers of application in three vegetables. The effects of pesticide residue levels on the δ13C, δ15N, δ2H, and δ18O values of vegetables were analyzed by one-way analysis of variance and correlation analysis. Partial least squares discriminant analysis (PLS-DA) was applied to build discrimination models of the vegetables with different pesticide residues based on stable isotopes. The results showed that the first degradation residues of thiamethoxam and fenvalerate in spinach, cabbage, and lettuce conformed to primary reaction kinetic equations, but the degradation half-lives were long, and accumulation occurred in the second application. The differences in the four stable isotope ratios in the control group of the three vegetables were statistically significant, and two-thirds of the stable isotope ratios in the three vegetables with different numbers of pesticide applications were significantly different. The δ13C and δ15N values of spinach, the δ13C, δ15N, and δ2H values of cabbage, and the δ13C, δ15N, δ2H, and δ18O values of lettuce were significantly correlated with different residues of thiamethoxam and/or fenvalerate applications. The control groups of the three vegetables, spinach-thiamethoxam-first, spinach-thiamethoxam-second, cabbage-thiamethoxam-second, cabbage-fenvalerate-first, and lettuce-thiamethoxam-first, were fully identified by PLS-DA models, while the identification models of other vegetables containing pesticide residues still need to be further improved. The results provide technical support for identifying the rational use of pesticides in vegetables and provide a reference method for guaranteeing the authenticity of green and organic vegetables.

Proteomic characteristics reveal the signatures and the risks of T1 colorectal cancer metastasis to lymph nodes.

The presence of lymph node metastasis (LNM) affects treatment strategy decisions in T1NxM0 colorectal cancer (CRC), but the currently used clinicopathological-based risk stratification cannot predict LNM accurately. In this study, we detected proteins in formalin-fixed paraffin-embedded (FFPE) tumor samples from 143 LNM-negative and 78 LNM-positive patients with T1 CRC and revealed changes in molecular and biological pathways by label-free liquid chromatography tandem mass spectrometry (LC-MS/MS) and established classifiers for predicting LNM in T1 CRC. An effective 55-proteins prediction model was built by machine learning and validated in a training cohort (N=132) and two validation cohorts (VC1, N=42; VC2, N=47), achieved an impressive AUC of 1.00 in the training cohort, 0.96 in VC1 and 0.93 in VC2, respectively. We further built a simplified classifier with nine proteins, and achieved an AUC of 0.824. The simplified classifier was performed excellently in two external validation cohorts. The expression patterns of 13 proteins were confirmed by immunohistochemistry, and the IHC score of five proteins was used to build an IHC predict model with an AUC of 0.825. RHOT2 silence significantly enhanced migration and invasion of colon cancer cells. Our study explored the mechanism of metastasis in T1 CRC and can be used to facilitate the individualized prediction of LNM in patients with T1 CRC, which may provide a guidance for clinical practice in T1 CRC.

Most patients with early-stage colorectal cancer can be treated with a minimally invasive procedure. Surgeons use a flexible tool to remove precancerous or cancerous cells, cutting the risk of death from colorectal cancer in half. But a small number of early-stage colorectal cancer patients are at risk of their cancer spreading to the lymph nodes. These patients need more extensive surgery. Clinicians use risk stratification tools to decide which patients need more extensive surgery. Unfortunately, the existing risk stratification tools are not very accurate. The current approach, which analyzes colon tissue for cancerous changes, classifies 70% to 80% of early-stage colorectal cancer patients as high risk for cancer spread. But only about 8% to 16% of patients in the high risk group have lymph node metastasis. As a result, many patients undergo unnecessary, invasive surgery. Zhuang, Zhuang, Chen, Qin, et al. developed a more accurate way to predict which patients are at risk of lymph node metastasis using proteins. In the experiments, the team analyzed the proteins in tumor samples from 143 patients with early colorectal cancer who did not have lymph node metastases and 78 patients with metastases. Zhuang et al. then used machine learning to build a prediction tool that used 55 proteins to identify patients at risk of metastases. The new approach was more accurate than existing tools and simplified versions with only nine or five proteins also performed better than existing tools. This work provides preliminary evidence that protein-based models using as few as five proteins can more accurately identify which patients are at risk of metastasis. These models may reduce the number of patients who undergo unnecessary invasive surgery. The experiments also identified potential targets for therapies to prevent or treat lymph metastases. For example, they showed that low levels of the RHOT2 protein predict metastasis.

CXCR6+ Tumor-Associated Macrophages Identify Immunosuppressive Colon Cancer Patients with Poor Prognosis but Favorable Response to Adjuvant Chemotherapy.

We explored the infiltration and prognostic value of CXCR6+TAMs in all stages of colon cancer (CC) patients and assessed predictive ability as a biomarker for different ACT regimens among high-risk stage II and stage III patients in both primary and validation cohorts. Two independent cohorts of 360 and 126 consecutive colon cancer patients were enrolled from two medical centers of Zhongshan Hospital. Immunofluorescence and immunohistochemistry were performed to detect the density of CXCR6+TAMs and activated CD8+ T cells. The infiltration of CXCR6+TAMs was higher in tumor tissues and increased with advanced tumor stage. A high density of CXCR6+TAMs predicted worse overall survival (OS) in all CC patients (HR = 2.49, 95% CI = (1.68, 3.70), p < 0.001), and was an independent risk factor verified by Cox regression analysis (HR = 1.68, 95% CI = (1.09, 2.59), p = 0.019). For high-risk stage II and stage III patients with a high density of CXCR6+TAMs, better disease-free survival (DFS) (HR = 0.32, 95% CI = (0.11, 0.89), p = 0.003), and OS (HR = 0.28, 95% CI = (0.07, 1.11), p = 0.014) were observed in the 6-month treatment group. There was a negative relationship between the density of CXCR6+TAMs and CD8+ T cells (R = −0.51, p < 0.001) as well as activated CD8+ T cells (R = −0.54, p < 0.001). Higher levels of IL-6 and lower levels of IL-2R and TNF-α were expressed in high-CXCR6+ TAM-density patients, which indicates that CXCR6+TAMs contribute to an immunosuppressive microenvironment. CXCR6+TAMs predicted prognosis and response to different durations of ACT in CC patients. CXCR6+TAMs were associated with an immunosuppressive microenvironment and suppressed the activation of CD8+ T cells.

Tumor-infiltrated activated B cells suppress liver metastasis of colorectal cancers.

More than 40% of patients with late-stage colorectal cancer (CRC) develop liver metastasis (LM). Which immune cells play important roles in CRC-LM and contribute to the difference between left-sided CRC (LCC) and right-sided CRC (RCC) remain unclear. By single-cell RNA sequencing (scRNA-seq), we not only find that activated B cells are significantly depleted in CRC with LM, but also find a subtype of B cells developed from activated B cells, namely immature plasma cell population alpha (iMPA), highly correlated with metastasis. Mechanistically, inhibition of the Wnt and transforming growth factor ß (TGF-ß) pathways in cancer cell promotes activated B cell migration via the SDF-1-CXCR4 axis. This study reveals that B cell subpopulations in the tumor immune microenvironment (TIME) play a key role in CRC-LM as well as in LCC and RCC. The preventive effects of modulating B cell subpopulations in CRC may provide a rationale for subsequent drug development and CRC-LM management.

Application of oxycodone in anesthesia induction and overall management of Da Vinci robot-assisted nephrectomy: A randomized controlled trial.

BACKGROUND: This study aimed to evaluate the application of oxycodone in anesthesia induction and overall management of Da Vinci robot-assisted nephrectomy. METHODS: A total of 42 patients undergoing Da Vinci robot-assisted nephrectomy with general anesthesia were selected. They were randomly divided into 2 groups: patients were induced with oxycodone (oxycodone group) and were induced with sufentanil (sufentanil group). The vital signs at the following time points were recorded: after injection of induced drugs (T1), during glottis exposure (T2), immediately after intubation (T3), 1 minute (T4), 2 minute (T5), 3 minute (T6), 5 minute (T7), 10 minute (T8) after intubation, during skin incision (T9), at the end of suturing skin (T10), during extubation (T11), and during hemodynamic fluctuations intraoperatively (T`). Numerical rating scale, facial affective scale and monitoring of adverse events (visual analogue scale, NVAS) were evaluated postoperatively at 1 hour (T'"1), 3 hours (T""2), 6 hours (T""3), 12 hours (T""4), 24 hours (T""5), and 48 hours (T"'6). RESULTS: The systolic blood pressure, the diastolic blood pressure and the mean arterial blood pressure showed no statistically different changes between the 2 groups. There were no statistical differences in heart rate and respiratory rate among various timepoints intraoperatively. There were statistical differences in Bispectral index (BIS) scores in T6 between the 2 groups. The numerical rating scale and facial affective scale scores were significantly lower in oxycodone group. Anesthetized with oxycodone, the pain did not affect the sleep of patients after operation. Also, the postoperative QoR-40 scores were lower in oxycodone group. CONCLUSION: Compared with sufentanil, anesthesia induction with 0.3 mg/kg oxycodone in Da Vinci robot-assisted nephrectomy can achieve mild pain and mild adverse responses in patients postoperatively.

Single-cell RNA-sequencing analysis and characterisation of testicular cells in giant panda (Ailuropoda melanoleuca).

CONTEXT: The giant panda (Ailuropoda melanoleuca ) is a rare and endangered species to be preserved in China. The giant panda has a low reproductive capacity, and due to the scarcity of samples, studies on testes from giant panda are very limited, with little knowledge about the process of spermatogenesis in this species. AIMS: To establish the gene expression profiles in cells from the testis of a giant panda. METHODS: The 10×Genomics single-cell RNA-sequencing platform was applied to cells from the testis of an adult giant panda. KEY RESULTS: We identified eight testicular cell types including six somatic and two germ cell types from our single-cell RNA-sequencing datasets. We also identified the differentially expressed genes (DEGs) in each cell type, and performed functional enrichment analysis for the identified testicular cell types. Furthermore, by immunohistochemistry we explored the protein localisation patterns of several marker genes in testes from giant panda. CONCLUSIONS: Our study has for the first time established the gene expression profiles in cells from the testis of a giant panda. IMPLICATIONS: Our data provide a reference catalogue for spermatogenesis and testicular cells in the giant panda, laying the foundation for future breeding and preservation of this endangered species.

The m6A RNA Modification Quantity and the Prognostic Effect of Reader YTHDC2 in Colorectal Cancer.

Background: N6-methyladenosine (m6A) modification plays crucial roles in cancers. However, its alteration in colorectal cancer (CRC) is still poorly described. The purpose of this study is to explore the change of m6A modification and the function of m6A binding protein YTHDC2 in CRC. Methods: The global level of m6A modification was detected by mass spectrometry and dot blotting assay. The expression of YTHDC2 was investigated using The Cancer Genome Atlas and using real-time polymerase chain reaction (RT-qPCR), western blotting, and immunohistochemistry based on CRC tissues. Kaplan-Meier analysis and Cox proportional hazards regression were performed to analyze the prognostic value of YTHDC2. RNA immunoprecipitation (RIP)-seq and m6A immunoprecipitation (MeRIP)-seq were used to explore the direct targets of YTHDC2. Gene oncology (GO) and Gene Set Enrichment Analysis (GSEA) were used to explore the pathways that could be influenced by YTHDC2. Results: No significant difference was observed in the global level of m6A modification on total RNA or mRNA between CRC and adjacent nontumor tissues. We further found a significant decreasing of YTHDC2 in CRC tissues. Kaplan-Meier analysis indicated that lower expression of YTHDC2 was related to the worse disease-free survival and overall survival. In addition, lower expression of YTHDC2 was an independent worse prognostic factor in univariate and multivariate Cox regression analysis. Using YTHDC2-RIP-seq and MeRIP-seq, we identified that YTHDC2 could participate in several important biological signal pathways. Conclusions: In summary, this study suggested that the global level of m6A did not change in CRC and identified that lower YTHDC2 as a prognostic marker for worse survival of CRC.

The Establishment and Experimental Verification of an lncRNA-Derived CD8+ T Cell Infiltration ceRNA Network in Colorectal Cancer.

Background: Long noncoding RNAs (LncRNA) lead a vital role in colorectal cancer (CRC) development. The infiltrating CD8+ T cell is the main target of immunotherapy. Our study aimed to figure out the potential mechanism of lncRNAs regulating the function of CD8+ T cells in CRC. Methods: We collected bulk RNA-seq, miRNA-seq, and single-cell RNA-seq (scRNA-seq) data from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) database. The cibersort algorithm and correlation analysis were used to estimate the abundance of CD8+ T cells and screened out the most relevant lncRNAs. We used scRNA-seq data to identify the main cell lncRNA expressed. Furthermore, one competing endogenous RNA (ceRNA) network focusing on the potential mechanism of lncRNA-derived CD8+ T cell infiltration was constructed. We established a co-culture system to assess the immunosuppressive function of the lncRNA. And we evaluated the effects of the lncRNA on CD8+ T cell cytotoxicity by flow cytometry, qPCR, and clone formation assay. Results: Three CD8+ T cell infiltration-related lncRNAs were identified, and LINC00657 was expressed mainly in tumor cells, negatively associated with CD8+ T cell infiltration. Hsa-miRNA-1224-3p and hsa-miRNA-338-5p and SCD, ETS2, UBE2H, and YY1 were identified to construct the ceRNA network. Immunosuppression-related tumor marker CD155 was proved to be positively correlated with LINC00657 and mRNAs in the ceRNA network. In addition, we proved that LINC00657 could impair the cytotoxicity of CD8+ T cells, and its expression was positively associated with CD155 in vitro. Conclusions: We successfully constructed an lncRNA-derived CD8+ T cell infiltration ceRNA network in CRC. LINC00657 may play a leading role in the CRC immune escape and could be a novel immunotherapy target.

No.253 Lymph Nodes Metastasis in Left-Sided Colorectal Cancer Liver Metastasis (CRLM) Patients: Incidence and Prognosis.

Background: No.253 lymph node is the gateway to systemic metastasis for left-sided colorectal cancer. However, the value of D3 resection is still controversial. This study aimed to identify the incidence rate and prognostic value of 253LN metastasis in patients with left-sided colorectal cancer liver metastasis (CRLM) mainly through blood vessels and thus to provide theoretical basis for 253LN resection. Methods: From February 2012 to February 2019, a total of 281 patients who underwent curative resection for both primary and metastatic tumors were collected retrospectively. The clinicopathological and genetic characteristics were compared between 58 patients with positive 253LN and 223 patients with negative. Relapse-free survival (RFS) and overall survival (OS) were compared with Kaplan-Meier method. Cox regression analysis and a forest plot were conducted for RFS. Results: The incidence of 253LN metastasis in left-sided CRLM was 20.64% (58/281). Those with 253LN positive were T4 stage, N2 stage, and D1/D2 lymph nodes metastatic. About 10.3% (8/78) 253LN positive patients were D1/D2 negative. The 253LN metastasis was an independent risk factor for relapse after curative surgery, but not for OS. Patients with 253LN metastasis had worse RFS, especially in female, adenocarcinoma, poorly differentiated, pT3, preoperative serum CA199 < 37 U/mL, bilobar liver metastasis, without preoperative chemotherapy, KRAS, NRAS, or BRAF wild type. Conclusion: The incidence of 253LN metastasis in left-sided CRLM is 20.64%, and skip metastasis rate is 10.3%. The 253LN status is an independent prognostic risk factor for RFS but not for OS after curative surgery. Routine resection of 253LN should be applied in curative surgery of left-sided CRLM.