Randomized clinical trial on D2 lymphadenectomy versus D2 lymphadenectomy plus complete mesogastric excision in patients undergoing gastrectomy for cancer (DCGC01 study).

BACKGROUND: It is unknown whether D2 lymphadenectomy + complete mesogastric excision for gastric cancer improves survival compared with just D2 lymphadenectomy. METHODS: Between September 2014 and June 2018, patients with advanced gastric cancer were randomly assigned (1 : 1) to laparoscopic D2 lymphadenectomy or D2 lymphadenectomy + complete mesogastric excision gastrectomy. The modified intention-to-treat population was defined as patients who had pathologically confirmed gastric adenocarcinoma (pT1 N1-3 M0 and pT2-4 N0-3 M0). The primary endpoint was 3-year disease-free survival. Secondary endpoints were the recurrence pattern and overall survival. RESULTS: The median follow-up of patients in the D2 lymphadenectomy group (169 patients) and patients in the D2 lymphadenectomy +complete mesogastric excision group (169 patients) was 55 (interquartile range 37-60) months and 51 (interquartile range 40-60) months respectively. Recurrence occurred in 50 patients in the D2 lymphadenectomy group (29.6%) versus 33 patients in the D2 lymphadenectomy + complete mesogastric excision group (19.5%) (P = 0.032). The 3-year disease-free survival was 75.5% (95% c.i. 68.3% to 81.3%) in the D2 lymphadenectomy group versus 85.0% (95% c.i. 78.7% to 89.6%) in the D2 lymphadenectomy + complete mesogastric excision group (log rank P = 0.042). The HR for recurrence in the D2 lymphadenectomy + complete mesogastric excision group versus the D2 lymphadenectomy group was 0.64 (95% c.i. 0.41 to 0.99) by Cox regression (P = 0.045). The 3-year overall survival rate was 77.5% (95% c.i. 70.4% to 83.1%) in the D2 lymphadenectomy group versus 85.8% (95% c.i. 79.6% to 90.2%) in the D2 lymphadenectomy + complete mesogastric excision group (log rank P = 0.058). The HR for death in the D2 lymphadenectomy + complete mesogastric excision group versus the D2 lymphadenectomy group was 0.64 (95% c.i. 0.41 to 1.02) (P = 0.058). CONCLUSION: Compared with conventional D2 dissection, D2 lymphadenectomy + complete mesogastric excision is associated with better disease-free survival, but there is no statistically significant difference in overall survival. REGISTRATION NUMBER: NCT01978444 (http://www.clinicaltrials.gov).

Salmonella enterica Serovar Typhimurium Interacts with CD209 Receptors To Promote Host Dissemination and Infection.

Salmonella enterica serovar Typhimurium, a Gram-negative bacterium, can cause infectious diseases ranging from gastroenteritis to systemic dissemination and infection. However, the molecular mechanisms underlying this bacterial dissemination have yet to be elucidated. A study indicated that using the lipopolysaccharide (LPS) core as a ligand, S Typhimurium was able to bind human dendritic cell-specific intercellular adhesion molecule-3-grabbing nonintegrin (hCD209a), an HIV receptor that promotes viral dissemination by hijacking antigen-presenting cells (APCs). In this study, we showed that S Typhimurium interacted with CD209s, leading to the invasion of APCs and potentially the dissemination to regional lymph nodes, spleen, and liver in mice. Shielding of the exposed LPS core through the expression of O-antigen reduces dissemination and infection. Thus, we propose that similar to HIV, S Typhimurium may also utilize APCs via interactions with CD209s as a way to disseminate to the lymph nodes, spleen, and liver to initiate host infection.

The number of mesogastria containing metastatic lymph nodes predicts gastric cancer prognosis.

BACKGROUND: Previous studies have established the existence of the mesogastrium, dividing it into 6 sections. The mesogastrium is identified during surgery and used in surgical practice. The aim of the present study was to further investigate its role in gastric cancer prognosis. METHODS: Between January 2014 and January 2018, patients from the Tongji Hospital were included in this post hoc analysis, including data from a randomized clinical study (DCGC01; http://www. CLINICALTRIALS: gov, NCT01978444). Mesogastria containing metastatic lymph nodes were referred to as metastatic mesogastria. Pathology reports were examined to assess metastases in the mesogastrium. Survival was assessed using Kaplan-Meier curves and multivariable Cox models. RESULTS: Among the 479 patients, 230 (48.0%) had no lymph node metastasis, 34 (7.1%) had 1 metastatic mesogastrium, and 215 (44.9%) had 2 to 6 metastatic mesogastria. Multivariate analysis showed that the number of metastatic mesogastria and N stages were independent risk factors for patient prognosis. In general, a higher metastatic mesogastrium number is positively correlated with a worse prognosis. For identical N stages, 5-year survival rates for patients with 2 to 6 metastatic mesogastria were significantly lower than those for patients with 1 metastatic mesogastrium. CONCLUSION: The number of metastatic mesogastria serves as an independent prognostic factor from the N stage.

Golgi dispersal in cancer stem cells promotes chemoresistance of colorectal cancer via the Golgi stress response.

Chemotherapy is a crucial treatment for colorectal tumors. However, its efficacy is restricted by chemoresistance. Recently, Golgi dispersal has been suggested to be a potential response to chemotherapy, particularly to drugs that induce DNA damage. However, the underlying mechanisms by which Golgi dispersal enhances the capacity to resist DNA-damaging agents remain unclear. Here, we demonstrated that DNA-damaging agents triggered Golgi dispersal in colorectal cancer (CRC), and cancer stem cells (CSCs) possessed a greater degree of Golgi dispersal compared with differentiated cancer cells (non-CSCs). We further revealed that Golgi dispersal conferred resistance against the lethal effects of DNA-damaging agents. Momentously, Golgi dispersal activated the Golgi stress response via the PKCα/GSK3α/TFE3 axis, resulting in enhanced protein and vesicle trafficking, which facilitated drug efflux through ABCG2. Identification of Golgi dispersal indicated an unexpected pathway regulating chemoresistance in CRC.

Nuclear Softness Promotes the Metastatic Potential of Large-Nucleated Colorectal Cancer Cells via the ErbB4-Akt1-Lamin A/C Signaling Pathway.

Abnormal nuclear enlargement is a diagnostic and physical hallmark of malignant tumors. Large nuclei are positively associated with an increased risk of developing metastasis; however, a large nucleus is inevitably more resistant to cell migration due to its size. The present study demonstrated that the nuclear size of primary colorectal cancer (CRC) cells at an advanced stage was larger than cells at an early stage. In addition, the nuclei of CRC liver metastases were larger than those of the corresponding primary CRC tissues. CRC cells were sorted into large-nucleated cells (LNCs) and small-nucleated cells (SNCs). Purified LNCs exhibited greater constricted migratory and metastatic capacity than SNCs in vitro and in vivo. Mechanistically, ErbB4 was highly expressed in LNCs, which phosphorylated lamin A/C at serine 22 via the ErbB4-Akt1 signaling pathway. Furthermore, the level of phosphorylated lamin A/C was a negative determinant of nuclear stiffness. Taken together, CRC LNCs possessed greater constricted migratory and metastatic potential than SNCs due to ErbB4-Akt1-mediated lamin A/C phosphorylation and nuclear softening. These results may provide a potential treatment strategy for tumor metastasis by targeting nuclear stiffness in patients with cancer, particularly CRC.

Defining the restriction point in normal asynchronous human peripheral blood lymphocytes.

Although the restriction point (R-point) was proposed in animal cells several decades ago, its existence in normal cells is still controversial, because, in most studies, long-term cultured cell lines rather than primary normal cells were used. Furthermore, cell synchronization was generally applied, resulting in growth imbalance between DNA synthesis and protein expression in cells. Finally, R-point was originally proposed as a unique arrest point that may be in G0 phase; however, generally believed R-point locates within G1 phase. Thus, up to now, there is no solid experimental evidence that supports the existence of R-point in asynchronous primary normal cells. In this study, we used freshly purified peripheral human blood lymphocytes, as asynchronous primary normal cells, to confirm the existence of restriction point in G1 not G0 phase. Our findings may help uncover the mystery of the deregulation of cell cycle progression in malignant tumors. © 2013 International Society for Advancement of Cytometry.

Sumoylation activates the transcriptional activity of Pax-6, an important transcription factor for eye and brain development.

Pax-6 is an evolutionarily conserved transcription factor regulating brain and eye development. Four Pax-6 isoforms have been reported previously. Although the longer Pax-6 isoforms (p46 and p48) bear two DNA-binding domains, the paired domain (PD) and the homeodomain (HD), the shorter Pax-6 isoform p32 contains only the HD for DNA binding. Although a third domain, the proline-, serine- and threonine-enriched activation (PST) domain, in the C termini of all Pax-6 isoforms mediates their transcriptional modulation via phosphorylation, how p32 Pax-6 could regulate target genes remains to be elucidated. In the present study, we show that sumoylation at K91 is required for p32 Pax-6 to bind to a HD-specific site and regulate expression of target genes. First, in vitro-synthesized p32 Pax-6 alone cannot bind the P3 sequence, which contains the HD recognition site, unless it is preincubated with nuclear extracts precleared by anti-Pax-6 but not by anti-small ubiquitin-related modifier 1 (anti-SUMO1) antibody. Second, in vitro-synthesized p32 Pax-6 can be sumoylated by SUMO1, and the sumoylated p32 Pax-6 then can bind to the P3 sequence. Third, Pax-6 and SUMO1 are colocalized in the embryonic optic and lens vesicles and can be coimmunoprecipitated. Finally, SUMO1-conjugated p32 Pax-6 exists in both the nucleus and cytoplasm, and sumoylation significantly enhances the DNA-binding ability of p32 Pax-6 and positively regulates gene expression. Together, our results demonstrate that sumoylation activates p32 Pax-6 in both DNA-binding and transcriptional activities. In addition, our studies demonstrate that p32 and p46 Pax-6 possess differential DNA-binding and regulatory activities.

Artificial intelligence assists surgeons' decision-making of temporary ileostomy in patients with rectal cancer who have received anterior resection.

BACKGROUND: Due to the difficult evaluation of the risk of anastomotic leakage (AL) after rectal cancer resection, the decision to perform a temporary ileostomy is not easily distinguishable. The aim of the present study was to develop an artificial intelligence (AI) model for identifying the risk of AL to assist surgeons in the selective implementation of a temporary ileostomy. MATERIALS AND METHODS: The data from 2240 patients with rectal cancer who received anterior resection were collected, and these patients were divided into one training and two test cohorts. Five AI algorithms, such as support vector machine (SVM), logistic regression (LR), Naive Bayes (NB), stochastic gradient descent (SGD) and random forest (RF) were employed to develop predictive models using clinical variables and were assessed using the two test cohorts. RESULTS: The SVM model indicated good discernment of AL, and might have increased the implementation of temporary ileostomy in patients with AL in the training cohort (p < 0.001). Following the assessment of the two test cohorts, the SVM model could identify AL in a favorable manner, which performed with positive predictive values of 0.150 (0.091-0.234) and 0.151 (0.091-0.237), and negative predictive values of 0.977 (0.958-0.988) and 0.986 (0.969-0.994), respectively. It is important to note that the implementation of temporary ileostomy in patients without AL would have been significantly reduced (p < 0.001) and which would have been significantly increased in patients with AL (p < 0.05). CONCLUSION: The model (https://alrisk.21cloudbox.com/) indicated good discernment of AL, which may be used to assist the surgeon's decision-making of performing temporary ileostomy.

Early-onset locally advanced rectal cancer characteristics, a practical nomogram and risk stratification system: a population-based study.

Background: The purpose of this study is to construct a novel and practical nomogram and risk stratification system to accurately predict cancer-specific survival (CSS) of early-onset locally advanced rectal cancer (EO-LARC) patients. Methods: A total of 2440 patients diagnosed with EO-LARC between 2010 and 2019 were screened from the Surveillance, Epidemiology, and End Results (SEER) database. The pool of potentially eligible patients was randomly divided into two groups: a training cohort (N=1708) and a validation cohort (N=732). The nomogram was developed and calibrated using various methods, including the coherence index (C-index), receiver operating characteristic curve (ROC), calibration curves, and decision curves (DCA). A new risk classification system was established based on the nomogram. To compare the performance of this nomogram to that of the American Joint Committee on Cancer (AJCC) staging system, DCA, net reclassification index (NRI), and integrated discrimination improvement (IDI) were employed. Result: Seven variables were included in the model. The area under the ROC curve (AUC) for the training cohort was 0.766, 0.736, and 0.731 at 3, 6, and 9 years, respectively. Calibration plots displayed good consistency between actual observations and the nomogram's predictions. The DCA curve further demonstrated the validity of the nomination form in clinical practice. Based on the scores of the nomogram, all patients were divided into a low-risk group, a middle-risk group, and a high-risk group. NRI for the 3-, 6-, and 9-year CSS(training cohort: 0.48, 0.45, 0.52; validation cohort: 0.42, 0.37, 0.37), IDI for the 3-, 6-, and 9-year CSS (training cohort: 0.09, 0.10, 0.11; validation cohort: 0.07, 0.08, 0.08). The Kaplan-Meier curve revealed that the new risk classification system possesses a more extraordinary ability to identify patients in different risk groups than the AJCC staging. Conclusion: A practical prognostic nomogram and novel risk classification system have been developed to efficiently predict the prognosis of EO-LARC. These tools can serve as a guide to individualize patient treatment and improve clinical decision-making.

Automated machine learning-based model for predicting benign anastomotic strictures in patients with rectal cancer who have received anterior resection.

BACKGROUND: Benign anastomotic strictures (BAS) significantly impact patients' quality of life and long-term prognosis. However, the current clinical practice lacks accurate tools for predicting BAS. This study aimed to develop a machine-learning model to predict BAS in patients with rectal cancer who have undergone anterior resection. METHODS: Data from 1973 patients who underwent anterior resection for rectal cancer were collected. Multiple machine learning classification models were integrated to analyze the data and identify the optimal model. Model performance was evaluated using receiver operator characteristic (ROC) curves, decision curve analysis (DCA), and calibration curves. The Shapley Additive exPlanation (SHAP) algorithm was utilized to assess the impact of various clinical characteristics on the optimal model to enhance the interpretability of the model results. RESULTS: A total of 10 clinical features were considered in constructing the machine learning model. The model evaluation results indicated that the random forest (RF)model was optimal, with the area under the test set curve (AUC: 0.888, 95% CI: 0.810-0.965), accuracy: 0.792, sensitivity: 0.846, specificity: 0.791. The SHAP algorithm analysis identified prophylactic ileostomy, operative time, and anastomotic leakage as significant contributing factors influencing the predictions of the RF model. CONCLUSION: We developed a robust machine-learning model and user-friendly online prediction tool for predicting BAS following anterior resection of rectal cancer. This tool offers a potential foundation for BAS prevention and aids clinical practice by enabling more efficient disease management and precise medical interventions.

Machine learning model for prediction of low anterior resection syndrome following laparoscopic anterior resection of rectal cancer: A multicenter study.

BACKGROUND: Low anterior resection syndrome (LARS) severely impairs patient postoperative quality of life, especially major LARS. However, there are few tools that can accurately predict major LARS in clinical practice. AIM: To develop a machine learning model using preoperative and intraoperative factors for predicting major LARS following laparoscopic surgery of rectal cancer in Chinese populations. METHODS: Clinical data and follow-up information of patients who received laparoscopic anterior resection for rectal cancer from two medical centers (one discovery cohort and one external validation cohort) were included in this retrospective study. For the discovery cohort, the machine learning prediction algorithms were developed and internally validated. In the external validation cohort, we evaluated the trained model using various performance metrics. Further, the clinical utility of the model was tested by decision curve analysis. RESULTS: Overall, 1651 patients were included in the present study. Anastomotic height, neoadjuvant therapy, diverting stoma, body mass index, clinical stage, specimen length, tumor size, and age were the risk factors associated with major LARS. They were used to construct the machine learning model to predict major LARS. The trained random forest (RF) model performed with an area under the curve of 0.852 and a sensitivity of 0.795 (95%CI: 0.681-0.877), a specificity of 0.758 (95%CI: 0.671-0.828), and Brier score of 0.166 in the external validation set. Compared to the previous preoperative LARS score model, the current model exhibited superior predictive performance in predicting major LARS in our cohort (accuracy of 0.772 for the RF model vs 0.355 for the preoperative LARS score model). CONCLUSION: We developed and validated a robust tool for predicting major LARS. This model could potentially be used in the clinic to identify patients with a high risk of developing major LARS and then improve the quality of life.

Comprehensive abdominal composition evaluation of rectal cancer patients with anastomotic leakage compared with body mass index-matched controls.

BACKGROUND: Anastomotic leakage (AL) is a fatal complication in patients with rectal cancer after undergoing anterior resection. However, the role of abdominal composition in the development of AL has not been studied. AIM: To investigate the relationship between abdominal composition and AL in rectal cancer patients after undergoing anterior resection. METHODS: A retrospective case-matched cohort study was conducted. Complete data for 78 patients with AL were acquired and this cohort was defined as the AL group. The controls were matched for the same sex and body mass index (± 1 kg/m2). Parameters related to abdominal composition including visceral fat area (VFA), subcutaneous fat area (SFA), subcutaneous fat thickness (SFT), skeletal muscle area (SMA), skeletal muscle index (SMI), abdominal circumference (AC), anterior to posterior diameter of abdominal cavity (APD), and transverse diameter of abdominal cavity (TD) were evaluated based on computed tomography (CT) images using the following Hounsfield Unit (HU) thresholds: SFA: -190 to -30, SMA: -29 to 150, and VFA: -150 to -20. The significance of abdominal composition-related parameters was quantified using feature importance analysis; an artificial intelligence method was used to evaluate the contribution of each included variable. RESULTS: Two thousand two hundred and thirty-eight rectal cancer patients who underwent anterior resection from 2010 to 2020 in a large academic hospital were investigated. Finally, 156 cases were enrolled in the study. Patients in the AL group showed longer operative time (225.03 ± 55.29 vs 207.17 ± 40.80, P = 0.023), lower levels of preoperative hemoglobin (123.32 ± 21.17 vs 132.60 ±1 6.31, P = 0.003) and albumin (38.34 ± 4.01 vs 40.52 ± 3.97, P = 0.001), larger tumor size (4.07 ± 1.36 vs 2.76 ± 1.28, P < 0.001), and later cancer stage (P < 0.001) compared to the controls. Patients who developed AL exhibited a larger VFA (125.68 ± 73.59 vs 97.03 ± 57.66, P = 0.008) and a smaller APD (77.30 ± 23.23 vs 92.09 ± 26.40, P < 0.001) and TD (22.90 ± 2.23 vs 24.21 ± 2.90, P = 0.002) compared to their matched controls. Feature importance analysis revealed that TD, APD, and VFA were the three most important abdominal composition-related features. CONCLUSION: AL patients have a higher visceral fat content and a narrower abdominal structure compared to matched controls.

Lactate promotes metastasis of normoxic colorectal cancer stem cells through PGC-1α-mediated oxidative phosphorylation.

Uneven oxygen supply in solid tumors leads to hypoxic and normoxic regions. Hypoxic cells exhibit increased secretion of lactate, which creates an acidic tumor microenvironment (TME). This acidic TME is positively associated with tumor metastasis. Despite the increased metastatic capacity of hypoxic cells, they are located relatively further away from the blood vessels and have limited access to the circulatory system. Studies have shown that cancer stem cells (CSCs) are enriched for tumor metastasis-initiating cells and generally undergo aerobic respiration, which could be enhanced by lactate. We therefore hypothesized that TME-derived lactate may promote the metastasis of normoxic CSCs. In the present study, the abundance of hypoxic and normoxic CSCs was analyzed in primary CRC tumors. It was found that the proportion of normoxic CSCs was positively associated with tumor stage. Using two human CRC cell lines, LoVo and SW480, and a patient-derived xenograft (XhCRC), it was found that treatment with lactate promoted normoxic CSC metastasis. Metabolism analysis indicated that, upon treatment with lactate, oxidative phosphorylation (OXPHOS) activity in normoxic CSCs was enhanced, whereas hypoxic CSCs were rarely altered. At the molecular level, the expression of peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α), a master regulator of lactate oxidation, was found to be elevated in normoxic CSCs. Furthermore, PGC-1α knockdown markedly reduced the metastatic potential of normoxic CSCs. Notably, both the PGC-1α-mediated OXPHOS activity and metastatic potential were impaired when hypoxia-inducible factor-1α (HIF-1α) was activated in normoxic CSCs. Together, these findings provide a therapeutic strategy against tumor metastasis through the targeting of PGC-1α and, thus, the suppression of lactate-feeding OXPHOS in normoxic CSCs may improve the therapeutic benefit of patients with cancer, particularly CRC.

Clinical Outcomes of Ileostomy Closure before Adjuvant Chemotherapy after Rectal Cancer Surgery: An Observational Study from a Chinese Center.

BACKGROUND: The optimal timing of temporary ileostomy closure with respect to the time of adjuvant chemotherapy following sphincter-saving surgery for rectal cancer remains unclear. The aim of this study is to investigate the clinical and oncological outcomes of ileostomy closure before, during, and after adjuvant chemotherapy following curative rectal cancer resection. METHODS: Patients diagnosed with rectal adenocarcinoma who underwent low anterior resection and temporary loop ileostomy during May 2015 and September 2019 were retrospectively evaluated. Patients undergoing ileostomy closure before adjuvant chemotherapy (Group I) were compared to patients undergoing closure during (Group II) and after (Group III) adjuvant chemotherapy. RESULTS: A total of 225 patients were evaluated for eligibility, and 132 were finally selected and divided into 3 groups (24 in Group I, 53 in Group II, and 55 in Group III). No significant differences were observed in operative time, postoperative hospital stay, postoperative complications, total adjuvant chemotherapy cycles, and low anterior resection syndrome scores among the three groups. There was no significant difference in disease-free survival (p = 0.834) and overall survival (p = 0.462) between the three groups. CONCLUSION: Temporary ileostomy closure before adjuvant chemotherapy following curative rectal cancer resection can achieve a clinical and oncological safety level equal to stoma closure during or after chemotherapy in selected patients.

Application of Machine Learning for Predicting Anastomotic Leakage in Patients with Gastric Adenocarcinoma Who Received Total or Proximal Gastrectomy.

Anastomotic leakage is a life-threatening complication in patients with gastric adenocarcinoma who received total or proximal gastrectomy, and there is still no model accurately predicting anastomotic leakage. In this study, we aim to develop a high-performance machine learning tool to predict anastomotic leakage in patients with gastric adenocarcinoma received total or proximal gastrectomy. A total of 1660 cases of gastric adenocarcinoma patients who received total or proximal gastrectomy in a large academic hospital from 1 January 2010 to 31 December 2019 were investigated, and these patients were randomly divided into training and testing sets at a ratio of 8:2. Four machine learning models, such as logistic regression, random forest, support vector machine, and XGBoost, were employed, and 24 clinical preoperative and intraoperative variables were included to develop the predictive model. Regarding the area under the receiver operating characteristic curve (AUC), sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy, random forest had a favorable performance with an AUC of 0.89, a sensitivity of 81.8% and specificity of 82.2% in the testing set. Moreover, we built a web app based on random forest model to achieve real-time predictions for guiding surgeons' intraoperative decision making.

Complete mesogastric excision for locally advanced gastric cancer: short-term outcomes of a randomized clinical trial.

Implementation of complete mesogastric excision in gastric cancer surgery, named D2 lymphadenectomy plus complete mesogastric excision (D2+CME), has recently been proposed as an optimal procedure. However, the safety and efficacy of D2+CME remain uncertain. In this randomized controlled trial, patients receiving D2+CME exhibit less intraoperative blood loss, more lymph node harvesting, and earlier postoperative flatus than patients receiving conventional D2 radical surgery. Univariate Cox regression analysis reveals that the risk ratio for postoperative flatus in D2+CME group is 1.247 (p = 0.044). Overall postoperative complications are comparable between the two groups, but complications are significantly less severe in the D2+CME group than the D2 group (Clavien-Dindo classification grade ≥ IIIa: 4 D2+CME patients [11.8%] versus 9 D2 patients [33.3%]; p = 0.041). In conclusion, our work shows that D2+CME is associated with better short-term outcomes and surgical safety than conventional D2 dissection for patients with advanced gastric cancer.

Loss of the virulence plasmid by Shigella sonnei promotes its interactions with CD207 and CD209 receptors.

Introduction. Shigella sonnei, the cause of bacillary dysentery, belongs to Gram-negative enteropathogenic bacteria. S. sonnei contains a 210 kb virulence plasmid that encodes an O-antigen gene cluster of LPSs. However, this virulence plasmid is frequently lost during replication. It is well-documented that after losing the O-antigen and becoming rough strains, the Gram-negative bacteria may express an LPS core on its surface. Previous studies have suggested that by using the LPS core, Gram-negative bacteria can interact with several C-type lectin receptors that are expressed on antigen-presenting cells (APCs).Hypothesis/Gap Statement. S. sonnei by losing the virulence plasmid may hijack APCs via the interactions of LPS-CD209/CD207.Aim. This study aimed to investigate if the S. sonnei rough strain, by losing the virulence plasmid, interacted with APCs that express C-type lectins of human CD207, human CD209a and mouse CD209b.Methodology. SDS-PAGE silver staining was used to examine the O-antigen expression of S. sonnei WT and its rough strain. Invasion assays and inhibition assays were used to examine the ability of S. sonnei WT and its rough strain to invade APCs and investigate whether CD209 and CD207 are receptors for phagocytosis of rough S. sonnei. Animal assays were used to observe the dissemination of S. sonnei.Results. S. sonnei did not express O-antigens after losing the virulence plasmid. The S. sonnei rough strain invades with APCs, including human dendritic cells (DCs) and mouse macrophages. CD209 and CD207 are receptors for phagocytosis of rough S. sonnei. Expression of the O-antigen reduces the ability of the S. sonnei rough strain to be disseminated to mesenteric lymph nodes and spleens.Conclusion. This work demonstrated that S. sonnei rough strains - by losing the virulence plasmid - invaded APCs through interactions with CD209 and CD207 receptors.

Proliferation characteristics of CD133+ cell population in colorectal cancer.

In this study, CD133+ subpopulations were isolated from 41 primary colorectal cancer tissues, the proliferation and cell cycle distribution of the cells were examined without in vitro expansion, and then compared to those of cell lines. The detection of CD133 in colorectal cancer tissues, isolation of CD133+ and CD133- epithelial subpopulations, Ki-67/DNA multiparameter assay and cell volume analysis were flow cytometrically conducted. The results showed that Ki-67 expression was correlated with CD133 level in primary cancer tissues, while cell cycle G2/M phase distribution or clinicopathological characteristics was not. In addition, the CD133+ cells showed larger cell volume and higher Ki-67 expression as compared with CD133- cells. But there was no statistically significant difference in G(2)/M phase distribution between the two subpopulations. Our results demonstrated that the CD133+ subpopulation in colorectal cancer tissue contained more actively cycling and proliferating cells, which was not correlated to clinicopathological factors but might contribute to tumor progression and poor clinical outcome.

Differentiated cancer cell-originated lactate promotes the self-renewal of cancer stem cells in patient-derived colorectal cancer organoids.

Tumors harbor diverse compartments of cells with distinct metabolic properties and phenotypes, but the mechanism by which metabolic commensalism among distinct subsets of cancer cells affects tumor progression remains unclear. Colorectal cancer (CRC) has been reported to consist of cancer stem cells (CSCs) and differentiated cancer cells (non-CSCs). In the present study, organoid models were employed to show that CSCs and non-CSCs in CRC were characterized by distinct metabolic phenotypes. Treatment with either non-CSC-derived conditioned medium or exogenous lactate enhanced organoid-forming and tumor-initiating capacity of CSCs. In tumor regeneration assays with co-implanted CSCs and non-CSCs, the tumor-initiating activity was reduced when either monocarboxylate transporter (MCT)4 in non-CSCs or MCT1 in CSCs was silenced or inhibited. Mechanistically, oxiadative phosphorylation-derived reactive oxygen species in CSCs activated AKT-Wnt/ß-catenin signaling, which could be induced by lactate from non-CSCs. Overall, these results suggest that CSCs and non-CSCs possess distinct metabolic profiles and, unexpectedly, non-CSC-originated lactate promotes self-renewal of CSCs and thus contributes to CRC progression. Our findings establish a rationale for developing novel therapies targeting the metabolic commensalism between different cell populations in CRC.

Hypoxic colorectal cancer cells promote metastasis of normoxic cancer cells depending on IL-8/p65 signaling pathway.

Tumor heterogeneity is an important feature of malignant tumors, and cell subpopulations may positively interact to facilitate tumor progression. Studies have shown that hypoxic cancer cells possess enhanced metastatic capacity. However, it is still unclear whether hypoxic cancer cells may promote the metastasis of normoxic cells, which have greater access to the blood circulation. When cocultured with hypoxic CRC cells or treated with hypoxic CRC cell-derived CM, normoxic CRC cells possessed increased metastatic capacity. Furthermore, hypoxic CRC cell-derived CM was enriched in interleukin 8. Hypoxic CRC cell-derived CM and recombinant human IL-8 both enhanced the metastatic capacity of normoxic cells by increasing the phosphorylation of p65 and then by inducing epithelial-mesenchymal transition. Knockdown of IL-8 in hypoxic CRC cells or the use of an anti-IL-8 antibody attenuated the CM- or rhIL-8-induced prometastatic capacity of normoxic CRC cells. Inhibition or knockdown of p65 abrogated IL-8-induced prometastatic effects. Most importantly, hypoxia-treated xenograft tumors enhanced the metastasis of normoxic CRC cells. Hypoxic CRC cell-derived IL-8 promotes the metastatic capacity of normoxic cells, and novel therapies targeting the positive interactions between hypoxic and normoxic cells should be developed.