Acetylation of aldehyde dehydrogenase ALDH1L2 regulates cellular redox balance and the chemosensitivity of colorectal cancer to 5-fluorouracil.

Folate-mediated one-carbon metabolism (FOCM) is crucial in sustaining rapid proliferation and survival of cancer cells. The folate cycle depends on a series of key cellular enzymes, including aldehyde dehydrogenase 1 family member L2 (ALDH1L2) that is usually overexpressed in cancer cells, but the regulatory mechanism of ALDH1L2 remains undefined. In this study, we observed the significant overexpression of ALDH1L2 in colorectal cancer (CRC) tissues, which is associated with poor prognosis. Mechanistically, we identified that the acetylation of ALDH1L2 at the K70 site is an important regulatory mechanism inhibiting the enzymatic activity of ALDH1L2 and disturbing cellular redox balance. Moreover, we revealed that sirtuins 3 (SIRT3) directly binds and deacetylates ALDH1L2 to increase its activity. Interestingly, the chemotherapeutic agent 5-fluorouracil (5-Fu) inhibits the expression of SIRT3 and increases the acetylation levels of ALDH1L2 in colorectal cancer cells. 5-Fu-induced ALDH1L2 acetylation sufficiently inhibits its enzymatic activity and the production of NADPH and GSH, thereby leading to oxidative stress-induced apoptosis and suppressing tumor growth in mice. Furthermore, the K70Q mutant of ALDH1L2 sensitizes cancer cells to 5-Fu both in vitro and in vivo through perturbing cellular redox and serine metabolism. Our findings reveal an unknown 5-Fu-SIRT3-ALDH1L2 axis regulating redox homeostasis, and suggest that targeting ALDH1L2 is a promising therapeutic strategy to sensitize tumor cells to chemotherapeutic agents.

LINC01852 inhibits the tumorigenesis and chemoresistance in colorectal cancer by suppressing SRSF5-mediated alternative splicing of PKM.

BACKGROUND: Colorectal cancer (CRC) is a major cause of cancer-related deaths worldwide, and chemoresistance is a major obstacle in its treatment. Despite advances in therapy, the molecular mechanism underlying chemoresistance in CRC is not fully understood. Recent studies have implicated the key roles of long noncoding RNAs (lncRNAs) in the regulation of CRC chemoresistance. METHODS: In this study, we investigated the role of the lncRNA LINC01852 in CRC chemoresistance. LINC01852 expression was evaluated in multiple CRC cohorts using quantitative reverse transcription PCR. We conducted in vitro and in vivo functional experiments using cell culture and mouse models. RNA pull-down, RNA immunoprecipitation, chromatin immunoprecipitation, and dual luciferase assays were used to investigate the molecular mechanism of LINC01852 in CRC. RESULTS: Our findings revealed that a lncRNA with tumor-inhibiting properties, LINC01852, was downregulated in CRC and inhibited cell proliferation and chemoresistance both in vitro and in vivo. Further mechanistic investigations revealed that LINC01852 increases TRIM72-mediated ubiquitination and degradation of SRSF5, inhibiting SRSF5-mediated alternative splicing of PKM and thereby decreasing the production of PKM2. Overexpression of LINC01852 induces a metabolic switch from aerobic glycolysis to oxidative phosphorylation, which attenuates the chemoresistance of CRC cells by inhibiting PKM2-mediated glycolysis. CONCLUSIONS: Our results demonstrate that LINC01852 plays an important role in repressing CRC malignancy and chemoresistance by regulating SRSF5-mediated alternative splicing of PKM, and that targeting the LINC01852/TRIM72/SRSF5/PKM2 signaling axis may represent a potential therapeutic strategy for CRC.

Long noncoding RNA DLGAP1-AS2 promotes tumorigenesis and metastasis by regulating the Trim21/ELOA/LHPP axis in colorectal cancer.

BACKGROUND: Long noncoding RNAs (lncRNAs) have driven research focused on their effects as oncogenes or tumor suppressors involved in carcinogenesis. However, the functions and mechanisms of most lncRNAs in colorectal cancer (CRC) remain unclear. METHODS: The expression of DLGAP1-AS2 was assessed by quantitative RT-PCR in multiple CRC cohorts. The impacts of DLGAP1-AS2 on CRC growth and metastasis were evaluated by a series of in vitro and in vivo assays. Furthermore, the underlying mechanism of DLGAP1-AS2 in CRC was revealed by RNA pull down, RNA immunoprecipitation, RNA sequencing, luciferase assays, chromatin immunoprecipitation, and rescue experiments. RESULTS: We discovered that DLGAP1-AS2 promoted CRC tumorigenesis and metastasis by physically interacting with Elongin A (ELOA) and inhibiting its protein stability by promoting tripartite motif containing 21 (Trim21)-mediated ubiquitination modification and degradation of ELOA. In particular, we revealed that DLGAP1-AS2 decreases phospholysine phosphohistidine inorganic pyrophosphate phosphatase (LHPP) expression by inhibiting ELOA-mediated transcriptional activating of LHPP and thus blocking LHPP-dependent suppression of the AKT signaling pathway. In addition, we also demonstrated that DLGAP1-AS2 was bound and stabilized by cleavage and polyadenylation specificity factor (CPSF2) and cleavage stimulation factor (CSTF3). CONCLUSIONS: The discovery of DLGAP1-AS2, a promising prognostic biomarker, reveals a new dimension into the molecular pathogenesis of CRC and provides a prospective treatment target for this disease.

A novel high-risk subpopulation identified by CTSL and ZBTB7B in gastric cancer.

BACKGROUND: Gastric cancer (GC) is characterised by a heterogeneous tumour microenvironment (TME) that is closely associated with the response to treatment, especially immunotherapies. However, most previous GC molecular subtyping systems need complex gene signatures and examination methods, restricting their clinical applications. Thus, we developed a new TME-based molecular subtype using only two genes. METHODS: Nine independent GC cohorts at the tissue- or single-cell level with more than 2000 patients were used in this study, including data we examined by single-cell sequencing, quantitative RT-PCR and immunochemistry/immunofluorescence staining. Nine different methods, five existing molecular subtypes and a series of signatures were used to evaluate the TME and molecular characteristics of GC. RESULTS: We established a CTSL/ZBTB7B subtyping system and uncovered the novel CTSLHighZBTB7BLow high-risk subgroup, but characterised by relative higher immune cell infiltration and lower tumour purity. This subgroup demonstrate higher levels of immune checkpoints and more enrichment of cancer-related pathways compared with other cases. CONCLUSIONS: We identified a high-risk subpopulation with unique TME features based on expressions of CTSL and ZBTB7B, suggesting a counterbalancing phenotype between immunostimulatory and immunosuppressive mechanisms. This subtyping system could be used to select treatment and management strategies for GC.

SLCO4A1-AS1 promotes colorectal tumourigenesis by regulating Cdk2/c-Myc signalling.

BACKGROUND: SLCO4A1-AS1 was found to be upregulated in several cancer types, including colorectal cancer (CRC). However, the detailed roles of SLCO4A1-AS1 in CRC remain to be elucidated. Therefore, we investigated the functions, mechanism, and clinical significance of SLCO4A1-AS1 in colorectal tumourigenesis. METHODS: We measured the expression of SLCO4A1-AS1 in CRC tissues using qRT-PCR and determined its correlation with patient prognosis. Promoter methylation analyses were used to assess the methylation status of SLCO4A1-AS1. Gain- and loss-of-function assays were used to evaluate the effects of SLCO4A1-AS1 on CRC growth in vitro and in vivo. RNA pull-down, RNA immunoprecipitation, RNA-seq, luciferase reporter and immunohistochemistry assays were performed to identify the molecular mechanism of SLCO4A1-AS1 in CRC. RESULTS: SLCO4A1-AS1 was frequently upregulated in CRC tissues based on multiple CRC cohorts and was associated with poor prognoses. Aberrant overexpression of SLCO4A1-AS1 in CRC is partly attributed to the DNA hypomethylation of its promoter. Ectopic SLCO4A1-AS1 expression promoted CRC cell growth, whereas SLCO4A1-AS1 knockdown repressed CRC proliferation both in vitro and in vivo. Mechanistic investigations revealed that SLCO4A1-AS1 functions as a molecular scaffold to strengthen the interaction between Hsp90 and Cdk2, promoting the protein stability of Cdk2. The SLCO4A1-AS1-induced increase in Cdk2 levels activates the c-Myc signalling pathway by promoting the phosphorylation of c-Myc at Ser62, resulting in increased tumour growth. CONCLUSIONS: Our data demonstrate that SLCO4A1-AS1 acts as an oncogene in CRC by regulating the Hsp90/Cdk2/c-Myc axis, supporting SLCO4A1-AS1 as a potential therapeutic target and prognostic factor for CRC.

Retrospective study of total neoadjuvant therapy for locally advanced rectal cancer.

Aim: To compare treatment outcomes of total neoadjuvant therapy (TNT) and the standard treatment for locally advanced rectal cancer (LARC). Materials & methods: Patients with LARC (cT2-4 and/or cN1-2) who were treated with preoperative chemoradiotherapy plus induction and consolidation chemotherapy followed by surgery or the standard treatment were recruited. Pathologic complete response (pCR) rate, overall survival, disease-free survival and the sphincter preservation rate as well as safety were evaluated. Results: 49 cases were treated with TNT and 71 cases received the standard treatment. Multivariate analysis demonstrated that TNT and tumor size were independent risk factors for pCR. Grade 3 chemoradiotherapy toxicity and postoperative complications were similar between the two groups. Conclusion: TNT improved the pCR rate for patients with LARC, with tolerable toxicities.

Plain language summary Outcomes of two treatment schemes were compared for locally advanced rectal cancer (LARC), including the new preoperative treatment strategy and conventional standard preoperative chemoradiotherapy. The new preoperative treatment strategy includes the addition of four cycles of preoperative chemotherapy to the standard treatment. A total of 49 cases were treated with the new preoperative treatment strategy and 71 cases received the standard treatment. Patients treated with the new preoperative treatment demonstrated higher rates of tumor regression and organ preservation. Additionally, chemoradiotherapy-related toxicity and postoperative complications were similar between the two treatment schemes. However, neither treatment strategy prolonged the survival of patients with LARC. This new preoperative treatment strategy should be recommended first for LARC.

Prognostic value of CT radiomics in evaluating lymphovascular invasion in rectal cancer: Diagnostic performance based on different volumes of interest.

OBJECTIVES: This study aims to evaluate diagnostic performance of radiomic analysis using computed tomography (CT) to identify lymphovascular invasion (LVI) in patients diagnosed with rectal cancer and assess diagnostic performance of different lesion segmentations. METHODS: The study is applied to 169 pre-treatment CT images and the clinical features of patients with rectal cancer. Radiomic features are extracted from two different volumes of interest (VOIs) namely, gross tumor volume and peri-tumor tissue volume. The maximum relevance and the minimum redundancy, and the least absolute shrinkage selection operator based logistic regression analyses are performed to select the optimal feature subset on the training cohort. Then, Rad and Rad-clinical combined models for LVI prediction are built and compared. Finally, the models are externally validated. RESULTS: Eighty-three patients had positive LVI on pathology, while 86 had negative LVI. An optimal multi-mode radiology nomogram for LVI estimation is established. The area under the receiver operating characteristic curves of the Rad and Rad-clinical combined model in the peri-tumor VOI group are significantly higher than those in the tumor VOI group (Rad: peri-tumor vs. tumor: 0.85 vs. 0.68; Rad-clinical: peri-tumor vs. tumor: 0.90 vs 0.82) in the validation cohort. Decision curve analysis shows that the peri-tumor-based Rad-clinical combined model has the best performance in identifying LVI than other models. CONCLUSIONS: CT radiomics model based on peri-tumor volumes improves prediction performance of LVI in rectal cancer compared with the model based on tumor volumes.

SIRT5-mediated ME2 desuccinylation promotes cancer growth by enhancing mitochondrial respiration.

Mitochondrial malic enzyme 2 (ME2), which catalyzes the conversion of malate to pyruvate, is frequently upregulated during tumorigenesis and is a potential target for cancer therapy. However, the regulatory mechanism underlying ME2 activity is largely unknown. In this study, we demonstrate that ME2 is highly expressed in human colorectal cancer (CRC) tissues, and that ME2 knockdown inhibits the proliferation of CRC cells. Furthermore, we reveal that ME2 is succinylated and identify Sirtuins 5 (SIRT5) as an ME2 desuccinylase. Glutamine deprivation directly enhances the interaction of SIRT5 with ME2 and thus promotes SIRT5-mediated desuccinylation of ME2 at lysine 346, activating ME2 enzymatic activity. Activated ME2 significantly enhances mitochondrial respiration, thereby counteracting the effects of glutamine deprivation and supporting cell proliferation and tumorigenesis. Additionally, the levels of succinylated ME2 at K346 and SIRT5 in CRC tissues, which are negatively correlated, are associated with patient prognosis. These observations suggest that SIRT5-catalyzed ME2 desuccinylation is a key signaling event through which cancer cells maintain mitochondrial respiration and promote CRC progression under glutamine deficiency conditions, offering the possibility of targeting SIRT5-mediated ME2 desuccinylation for CRC treatment.

Metformin suppresses gastric cancer progression by disrupting the STAT1-PRMT1 axis.

Gastric cancer (GC) is a common form of cancer and the leading cause of cancer-related deaths worldwide. Chemotherapy is the primary treatment for patients with unresectable or partially resectable GC. However, its adverse effects and chemoresistance greatly restrict its applicability and efficacy. Although HER2-targeted therapy and immunotherapy have been successfully used for GC treatment, their beneficial population is limited. To expand the range of cancer treatments, drug repurposing has emerged as a promising strategy. In this study, we evaluated the potential of Metformin, an oral anti-hyperglycemic agent, to suppress GC progression both in vivo and in vitro. Functional investigations showed that Metformin significantly inhibits GC proliferation and migration. Furthermore, we discovered that Metformin bound and disrupted STAT1 phosphorylation, inhibiting PRMT1 expression and consequently GC progression. In conclusion, our study not only provides further evidence for the anti-GC role of Metformin but also identifies the direct target mediating the tumor-inhibitory effects of Metformin in GC.

YWHAG promotes colorectal cancer progression by regulating the CTTN-Wnt/ß-catenin signaling axis.

Colorectal cancer (CRC) ranks as the third most prevalent cancer type globally. Nevertheless, the fundamental mechanisms driving CRC progression remain ambiguous, and the prognosis for the majority of patients diagnosed at an advanced stage is dismal. YWHA/14-3-3 proteins serve as central nodes in several signaling pathways and are closely related to tumorigenesis and progression. However, their exact roles in CRC are still poorly elucidated. In this study, we revealed that YWHAG was the most significantly upregulated member of the YWHA/14-3-3 family in CRC tissues and was associated with a poor prognosis. Subsequent phenotypic experiments showed that YWHAG promoted the proliferation, migration, and invasion of CRC cells. Mechanistically, RNA-seq data showed that multiple signaling pathways, including Wnt and epithelial-mesenchymal transition, were potentially regulated by YWHAG. CTTN was identified as a YWHAG-associated protein, and mediated its tumor-promoting functions by activating the Wnt/ß-catenin signaling in CRC cells. In summary, our data indicate that YWHAG facilitates the proliferation, migration, and invasion of CRC cells by modulating the CTTN-Wnt/ß-catenin signaling pathway, which offers a novel perspective for the treatment of CRC.

Inhibition of gastric cancer cell growth in vivo by overexpression of adeno-associated virus-mediated survivin mutant C84A.

Survivin is overexpressed in most of human cancer cells and tissues. Its overexpression is associated with apoptosis inhibition, drug resistance, and poor prognosis. In this study, we investigated the effect of adeno-associated virus (AAV)-mediated survivin mutant Cys84Ala [rAAV-Sur-Mut(C84A)] on gastric cancer growth. Sur-Mut(C84A) was subcloned into the AAV expression vector pAM/CAG to generate recombinant (r)AAV-Sur-Mut(C84A) virus. Cell survival was determined by the MTT method. Apoptosis was measured by FACS analysis and TUNEL. Tumor growth was assessed using a xenograft mouse model. Results showed that treatment of rAAV-Sur-Mut(C84A) virus significantly reduced cell survival, induced apoptosis, and sensitized gastric cancer cells to 5-fluorouracil in vitro. Furthermore, treatment of rAAV-Sur-Mut(C84A) virus markedly induced apoptosis and inhibited gastric cancer growth in vivo. Moreover, rAAV-Sur-Mut(C84A) treatment strongly enhanced the antitumor activity of 5-fluorouracil. Our results suggest that the combination of rAAV-Sur-Mut(C84A) with chemotherapy may be a promising strategy for gastric cancer therapy.

Hydroxycamptothecin induces apoptosis and inhibits tumor growth in colon cancer by the downregulation of survivin and XIAP expression.

BACKGROUND: 10-Hydroxycamptothecin (10-HCPT), isolated from a Chinese tree Camptotheca acuminate, inhibits the activity of topoisomerase I and has a broad spectrum of anticancer activity in vitro and in vivo. It has been shown that HCPT is more active and less toxic than conventional camptothecins and can induce cancer cell apoptosis. However, the mechanisms of HCPT-induced apoptosis in colon cancer cells remain unclear. In this study, we investigated the effects of HCPT on apoptosis of colon cancer and underlying mechanism. METHODS: Cell proliferation was measured by MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide) assay, and apoptosis was measured using terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) assay. Expression of genes was detected using real-time reverse transcription-polymerase chain reaction (real time-PCR) and Western blot. Tumor growth in vivo was evaluated using a nude mouse xenograft model. RESULTS: HCPT could significantly inhibit cell proliferation and induce apoptosis in colon cancer SW1116 and Colo 205 cells in dose- and time-dependent manners. HCPT treatment activated the activities of caspase 3, 7, 8 and 9, downregulated the expression of survivin, survivinΔEx3, survivin-3B and XIAP, and upregulated expression of surviving 2B. Moreover, the combination of HCPT and 5-fluorouracial (5-FU) synergistically induced apoptosis and downregulated the expression of survivin and XIAP. Knockdown of survivin and XIAP by siRNA sensitized colon cancer to HCTP-induced apoptosis. Furthermore, HCPT treatment significantly inhibited SW1116 xenograft tumor growth. CONCLUSIONS: Our results elucidate new mechanisms of HCPT antitumor by the downregulation of survivin and XIAP expression. The combination of HCPT with 5-FU or IAP inhibitors may be a potential strategy for colon cancer treatment.

ELOA promotes tumor growth and metastasis by activating RBP1 in gastric cancer.

BACKGROUND: Elongin A (ELOA), our previous work revealed, serves as a novel tumor suppressor in colorectal cancer. However, the function and mechanism of ELOA in other cancer types, including gastric cancer (GC), remain to be elucidated. METHODS: The expression of ELOA was measured by quantitative reverse transcription-polymerase chain reaction and western blot. The effects of ELOA on GC growth and metastasis were assessed through a series of in-vitro and in-vivo assays. Furthermore, the potential mechanism of ELOA was revealed by RNA sequencing, dual luciferase reporter assay, chromatin immunoprecipitation, and rescue experiments in GC. RESULTS: We uncovered increased expression of ELOA in GC tissues compared with paired normal tissues via bioinformatic analyses and our sample detection. Enhanced ELOA expression in GC tissues was obviously correlated with poor tumor differentiation, lymph node metastasis, advanced tumor stage, and a poor prognosis. A series of functional experiments showed that ELOA promoted the proliferation and metastasis of GC. Mechanistically, we revealed that the decreased levels of miR-490-3p caused the upregulation of ELOA in GC. Both RNA-seq and ChIP assays revealed that ELOA transcriptionally activated retinol-binding protein 1 (RBP1) by binding to its promotor. Furthermore, specific knockdown of RBP1 reduced the tumor-promoting ability of ELOA in GC cells. CONCLUSIONS: In summary, our findings demonstrate that ELOA exerts oncogenic properties by activating RBP1 expression, providing the basis for a promising therapeutic target in GC.

KDM4C-mediated senescence defense is a targetable vulnerability in gastric cancer harboring TP53 mutations.

BACKGROUND: Gastric cancer patients harboring a TP53 mutation exhibit a more aggressive and chemoresistant phenotype. Unfortunately, efforts to identify the vulnerabilities to overcome these aggressive malignancies have made minimal progress in recent years. Therefore, there is an urgent need to explore the novel therapeutic strategies for this subclass. Histone methylation modulators are critical epigenetic targets for cancer therapies that help maintain the malignancies of cancers harboring TP53 mutations and senescence evasion. Triggering senescence is now considered to benefit multiple cancer therapies. Furthermore, senescence-based "one-two punch" therapy was validated in clinical trials. Therefore, we hypothesized that screening epigenetic modulators might help identify a novel vulnerability to trigger senescence in gastric cancer harboring TP53 mutations. RESULTS: We developed a novel efficient approach to identify senescence inducers by sequentially treating cells with drug candidates and senolytic agents. Based on this, we demonstrated that QC6352 (a selective KDM4C inhibitor) efficiently triggered cellular senescence in gastric cancer harboring TP53 mutations. More importantly, the "one-two punch' therapy consisting of QC6352 and SSK1 eliminates tumor cells harboring TP53 mutations. This finding highlights a potential therapeutic strategy for the aggressive subgroup of gastric cancer. Besides, the functions of QC6352 were totally unknown. We demonstrated that QC6352 might possess far more powerful anti-tumor capacities compared to the traditional genotoxic drugs, 5-Fu and Oxaliplatin. CONCLUSIONS: This initial investigation to identify a senescence inducer revealed that QC6352 triggers senescence in gastric cancer cells harboring TP53 mutations by regulating the SP1/CDK2 axis through suppressing KDM4C. QC6352 and senolytic agent-SSK1 represent a novel 'one-two punch' therapeutic strategy for the more malignant gastric cancer subtypes.

Effects of prebiotic supplement on gut microbiota, drug bioavailability, and adverse effects in patients with colorectal cancer at different primary tumor locations receiving chemotherapy: study protocol for a randomized clinical trial.

BACKGROUND: The prevalence of colorectal cancer (CRC) worldwide is a huge challenge to human health. Primary tumor locations found to impact prognosis and response to therapy. The important role of gut microbiota in the progression and treatment of CRC has led to many attempts of alleviating chemotherapy-induced adverse effects using microecologics. However, the underlying mechanism of the difference in the prognosis of different primary tumor locations and the synergistic effect of prebiotics on chemotherapy need to be further elucidated. This study aims to explore the differences in tumor microbiota and examine the effectiveness of xylooligosaccharides (XOS) on gut microbiota, adverse effects, and bioavailability of chemotherapy drugs in CRC patients at different primary tumor locations. METHODS: This is a double-blinded, randomized, parallel controlled clinical trial. Participants with left-sided CRC (LSCRC, n = 50) and right-sided CC (RSCC, n = 50) will randomly allocated to prebiotic group (n = 25) or control group (n = 25) and will receive either a daily XOS (3 g/day) or placebo, respectively, for 12 weeks. The primary outcomes will be the differences in the mucosa microbiota composition at different tumor locations and differences in gut microbiota composition, adverse effects, and blood concentration of capecitabine posttreatment. The secondary outcomes will include other blood indicators, short-chain fatty acids (SCFAs) concentration, quality of life, and mental health. DISCUSSION: This study will reveal the potential benefits of prebiotic for improving the gut microbiota composition, alleviating the adverse effects, and improving the efficacy of chemotherapy in patients with CRC. In addition, this study will provide data on the different distribution of tumor microbiota and the different changes of gut microbiota during treatment in LSCRC and RSCC, which may provide novel insights into personalized cancer treatment strategies based on primary tumor locations and gut microbiota in the future. TRIAL REGISTRATION: Chinese Clinical Trial Registry ( www.chictr.org.cn ): ChiCTR2100046237. Registered on 12 May 2021.

[Significance and expression of p53, p21(Cip1/WAF1) and Gadd45α in breast neoplasm tissues].

OBJECTIVE: To explore the expression and significance of p53, p21(Cip1/WAF1) and Gadd45α protein in breast cancer and their correlations with clinicopathologic features and prognosis in breast cancer. METHODS: The expressions of p53, p21(Cip1/WAF1) and Gadd45α proteins were determined by immunohistochemical staining. The relationship between these three proteins and clinicopathologic features in breast cancer was analyzed by χ(2) test and Spearman's rank correlation analysis. And the survival analyses were performed with the Kaplan-Meier method and Cox regression. The differences between the curves were examined with the two-tailed Log-rank test. RESULTS: In 133 cases of invasive breast cancer, the positive rates of p53, p21(Cip1/WAF1) and Gadd45α protein were 58.6%, 47.4% and 41.4% respectively. The expressions of p21(Cip1/WAF1) and p53 in cancer were significantly higher than those in the adjacent mammary gland tissue (P < 0.05) while the expression of Gadd45α was lower than that in the control mammary gland tissue (P < 0.05). The positive rate of p21(Cip1/WAF1) was correlated with the histological stage, local recurrence and positive C-erbB-2. And the positive rate of Gadd45α was correlated with the histological stage, lymph node metastasis, metastasis and positive estrogen receptor/progesterone receptor (ER/PR). The positive rate of p53 was correlated with the lymph node metastasis and TNM stage. Spearman's rank correlation analysis showed that p21(Cip1/WAF1) was correlated positively with p53, p53 negatively with Gadd45α while p21(Cip1/WAF1) had no correlation with Gadd45α. With the follow-up data, Kaplan-Meier analysis showed that p21(Cip1/WAF1), Gadd45α, p53, lymph node metastasis, C-erbB-2 positive and TMN stage were associated with prognosis. Furthermore, Cox stepwise hazard analysis shows that p21(Cip1/WAF1), Gadd45α, C-erbB-2 and TMN stage were correlated with prognosis of breast cancer. Also the Kaplan-Meier analysis showed that p53(+)Gadd45α(-) and p53(+)p21(Cip1/WAF1)(+) were correlated with a poor prognosis of breast cancer. CONCLUSIONS: The expressions of p21(Cip1/WAF1), Gadd45α and p53 are associated with the clinicopathologic features and prognosis in breast cancer. Indicating a poor prognosis of breast cancer, p53(+)Gadd45α(-) and p53(+)p21(Cip1/WAF1)(+) may become independent indices for prognostic evaluations.

A Comparison of Endoscopic Closure and Laparoscopic Repair for Gastric Wall Defection.

Objective: To compare the effectiveness and safety of endoscopic closure and laparoscopic repair for gastric wall defection. Method: The clinical data of 120 patients with submucosal tumours enrolled at our hospital between January 2014 and December 2019 were retrospectively analysed. Patients were divided into two groups according to the surgery they underwent: an endoscopic closure group (n = 60) and a laparoscopic repair group (n = 60). The clinical characteristics, perioperative complications, and postoperative follow-up results of the two groups were analysed. Results: The surgery time in the endoscopic closure group was 56.20 ± 11.25 minutes, which was significantly lower compared with that in the laparoscopic repair group (159.35 ± 23.18 minutes; P < 0.001). In addition, the postoperative stay in the endoscopic closure group was shorter than that in the laparoscopic repair group, and the intraoperative bleeding volume and incidence of enteral nutrition initiation after surgery were significantly lower. Medical expenses were also significantly lower in the endoscopic closure group than in the laparoscopic repair group (P < 0.001). Only one patient developed a postoperative fever in the endoscopic closure group; three patients developed a postoperative fever and one patient had postoperative bleeding in the laparoscopic repair group. However, there were no statistical differences between the two groups regarding the incidence of R0 resection, postoperative fever, postoperative bleeding, and closure failure (all P > 0.05). There were no local recurrences, distant metastases, or deaths in either of the groups during the two-year follow-up period. Conclusion: Non-laparoscopic-assisted surgery may be quicker, safer, and more effective for gastric wall defection.

Ferroptosis-Associated Molecular Features to Aid Patient Clinical Prognosis and Therapy Across Human Cancers.

Ferroptosis is a new non-apoptotic form that regulates cell death and is mainly dependent on iron-mediated oxidative damage and subsequent cell membrane damage. Ferroptosis may be a potential therapeutic strategy for immunotherapy, chemotherapy, and radiotherapy in human cancers. Numerous studies have analyzed ferroptosis-correlated signatures or genes, but a systematic landscape of associations among tumor ferroptosis, clinical outcomes, tumor microenvironment, and therapies in human cancers is lacking. Here, we developed a relative ferroptosis level (RFL) combined with drive/suppress regulators and validated it in the Gene Expression Omnibus datasets of ferroptotic drug treatment. Based on this effective evaluation method, we classified about 7,000 tumor samples into high and low RFL groups in each cancer type and observed that high RFL cases demonstrate favorable survival outcomes in nine cancer types from The Cancer Genome Atlas. Then, several RFL-correlated candidate genes that have not been reported to be ferroptosis-related were selected and experimentally validated in five cancer cell lines using Erastin treatment. We further showed that both immunostimulatory and immunosuppressive phenotypes were observed in high RFL tumors, suggesting that the consideration of ferroptosis could be a potential strategy in cancer immunotherapy. Moreover, we found that high RFL cases/cells showed responder or sensitivity to chemotherapy and radiotherapy. Our study provides a comprehensive molecular-level understanding of ferroptosis and may have practical implications for clinical cancer therapies, including immunotherapy, chemotherapy, and radiotherapy.

Gut Microbiota Signatures in Tumor, Para-Cancerous, Normal Mucosa, and Feces in Colorectal Cancer Patients.

Background: Association studies have linked microbiome alterations with colorectal cancer (CRC). However, differences in tumor, para-cancerous, normal mucosal, and fecal microbiota remain to be strengthened. Methods: We performed a study on the ecologically rich and taxonomically diverse of gut microbiota using three types of colorectal mucosa (tumor mucosa, para-cancerous mucosa, normal mucosa) and feces from 98 CRC patients. Additionally, we profiled the microbiota in the fecal occult blood test (FOBT) positive and negative groups at different sampling sites. Results: We found striking variations between tumor mucosal microbiota and normal mucosal microbiota. However, there was no significant difference between tumor and para-cancerous mucosal microbiota, as well as between para-cancerous and normal mucosal microbiota, revealing that the para-cancerous mucosal microbiota was a transitional state between the tumor and normal mucosal microbiota. And the substantial shifts in the fecal microbiota compared to mucosal microbiota indicated the risk of using fecal microbiota to define mucosal microbiota. A strong correlation between FOBT positive and Fusobacterium was discovered, indicating this adherent-invasive genus was closely related to intestinal bleeding. Furthermore, we identified six key genera, including Fusobacterium, Gemella, Campylobacter, Peptostreptococcus, Alloprevotella, and Parvimonas, which appear to be consistently over-represented in tumor mucosa compared to normal mucosa and/or in mucosa compared to feces. Conclusion: Compositional alterations in the microbiota existed in three types of colorectal mucosa and feces in CRC patients. Six key genera may contribute to the topographic variances in the microbiota of tumor-bearing colorectum.

Colorectal Cancer-Derived Small Extracellular Vesicles Promote Tumor Immune Evasion by Upregulating PD-L1 Expression in Tumor-Associated Macrophages.

Tumor-associated macrophages (TAMs) are one of the most abundant cell types in colorectal cancer (CRC) tumor microenvironment (TME). Recent studies observed complicated "cross-talks" between cancer cells and macrophages in TME. However, the underlying mechanisms are still poorly elucidated. Here, PD-L1 levels are very low in CRC cells but highly abundant in TAMs, and a specific PD-L1+CD206+ macrophage subpopulation are identified, which is induced by tumor cells and associated with a poor prognosis. Mechanistic investigations reveal that CRC cells can secrete small extracellular vesicles (sEVs) taken up by macrophages that induce M2 like polarization and PD-L1 expression, resulting in increased PD-L1+CD206+ macrophage abundance and decreased T cell activity in CRC TME. sEV-derived miR-21-5p and miR-200a are identified as key signaling molecules mediating the regulatory effects of CRC on macrophages. Further studies reveal that CRC-derived miR-21-5p and miR-200a synergistically induces macrophage M2 like polarization and PD-L1 expression by regulating the PTEN/AKT and SCOS1/STAT1 pathways, resulting in decreased CD8+ T cell activity and increased tumor growth. This study suggests that inhibiting the secretion of specific sEV-miRNAs from CRC and targeting PD-L1 in TAMs may serve as novel methods for CRC treatment as well as a sensitization method for anti-PD-L1 therapy in CRC.