[Comparison of short-term safety of two anastomotic techniques when resecting Siewert type II adenocarcinoma of the esophagogastric junction: a multicenter retrospective cohort study].

Objective: In this study, we aimed to compare the short-term safety of two digestive tract reconstruction techniques, laparoscopic total abdominal overlap anastomosis and laparoscopic-assisted end-to-side anastomosis, following radical resection of Siewert Type II adenocarcinoma of the esophagogastric junction. Methods: In this retrospective cohort study, we analyzed relevant clinical data of 139 patients who had undergone radical surgery for Siewert Type II esophagogastric junction adenocarcinoma. These included 89 patients treated at the First Affiliated Hospital of Air Force Medical University from November 2021 to July 2023, 36 patients treated at the First Affiliated Hospital of Xi'an Jiaotong University from December 2020 to June 2021, and 14 patients treated at the Yuncheng Central Hospital in Shanxi Province from September 2021 to November 2022. The group consisted of 107 men (77.0%) and 32 women (23.0%) of mean age 62.5±9.3 years. Forty-eight patients underwent laparoscopic total abdominal overlap anastomosis (overlap group), and 91 laparoscopic-assisted end-to-side anastomosis (end-to-side group). Clinical data, surgical information, pathological findings, postoperative recovery, and related complications were compared between the two groups. Results: There were no significant differences in general clinical data between the overlap and end-to-side anastomosis groups (all P>0.05), indicating comparability. There was no significant difference in operation time (267.2±60.1 minutes vs. 262.8±70.6 minutes, t=0.370, P=0.712). However, the intraoperative blood loss in the overlap group (100 [50, 100] mL) was significantly lower compared to the end-to-side group (100[50, 175] mL, Z=2.776, P=0.005). Compared to the end-to-side group, longer distances between the tumor and distal resection margin proximal(1.7±1.0 cm vs. 1.3±0.9 cm, t=2.487, P=0.014) and the tumor and distal resection margin (9.5±2.9 cm vs. 7.9±3.5 cm, t=2.667, P=0.009) were achieved in the overlap group. Compared with the end-to-side group, the overlap group achieved significantly earlier postoperative ambulation (1.0 [1.0, 2.0] days vs. 2.0 [1.0, 3.0] days, Z=3.117, P=0.002), earlier time to first drink (4.7±2.6 days vs. 6.2±3.0 days, t=2.851, P=0.005), and earlier time to first meal (6.0±2.7 days vs. 7.1±3.0 days, t=2.170, P=0.032). However, the hospitalization costs were higher in the overlap group (113, 105.5±37, 766.3) yuan vs. (97, 250.2±27, 746.9) yuan; this difference is significant (t=2.818, P=0.006). There were no significant differences between the two groups in postoperative hospital stay, total number of lymph nodes cleared, or time to first postoperative flatus (all P>0.05). The incidence of surgery-related complications was 22.9%(11/48) in the overlap group and 19.8% (18/91) in the end-to-side group; this difference is not significant (χ²=0.187, P=0.831). Further comparison of complications using the Clavien-Dindo classification also showed no significant differences (Z=0.406, P=0.685). Conclusions: Both laparoscopic total abdominal overlap anastomosis and laparoscopic-assisted end-to-side anastomosis are feasible for radical surgery for Siewert Type II esophagogastric junction adenocarcinoma. Laparoscopic total abdominal overlap anastomosis achieves longer proximal and distal resection margins and better postoperative recovery; however, end-to-side anastomosis is more cost-effective.

[Management of radiation-induced intestinal injury:from multi-disciplinary team team to holistic integrative management].

Radiation-induced intestinal injury is a radiation injury of the colon and rectum after radiotherapy for pelvic malignant tumors. This condition affects multiple organs in the pelvis, making treatment challenging. In clinical practice, the most effective protocol is often determined through discussion by a multi-disciplinary team (MDT). However, due to the severity and complexity of radiation enteritis, many patients still experience poor diagnosis and treatment outcomes. Holistic integrative management (HIM) is a rapidly developing concept that has greatly enhanced clinical medicine in recent years. It improves the level of diagnosis, treatment, prevention, and rehabilitation from multiple dimensions of prevention, screening, diagnosis, treatment, and rehabilitation. In the context of radiation-induced intestinal injury, HIM also calls for the implementation of an individualized management system that focuses on the patient as a whole within the healthcare team. From the perspective of HIM, this article introduces some of the latest progress of radiation-induced intestinal injury in recent years.

[The correlation between No. 6 and No. 14v lymph node metastasis and the value of dissecting these lymph nodes in radical gastrectomy].

Radical gastrectomy with D2 lymphadenectomy has been widely performed as the standard surgery for patients with gastric cancer in major medical centers in China and abroad. However, the exact extent of lymph node dissection is still controversial. In the latest version of the Japanese Gastric Cancer Treatment Guidelines, No. 14v lymph nodes (along the root of the superior mesenteric vein) are again defined as loco-regional lymph nodes, and it is clarified that distal gastric cancer presenting with infra-pyloric regional lymph node (No.6) metastasis is recommended for D2+ superior mesenteric vein (No. 14v) lymph node dissection. To explore the relevance and clinical significance of No.6 and No.14v lymphadenectomy in radical gastric cancer surgery, a review of the national and international literature revealed that No.6 lymph node metastasis was associated with No.14v lymph node metastasis, that No.6 lymph node status was a valid predictor of No.14v lymph node negative status and false negative rate, and that for gastric cancer patients with No. 14v lymph node negative and No.6 lymph node positive, the dissection of No.14v lymph node may also have some significance. The addition of No. 14v lymph node dissection in radical gastrectomy is safe, but it is more important to distinguish the patients who can benefit from it. Professor Liang Han of Tianjin Medical University Cancer Hospital is currently leading a multicenter, large-sample, prospective clinical trial (NCT02272894) in China, which is expected to provide higher level evidence for the clinical significance of lymph node dissection in No.14v.

[Functional outcomes of 100 patients with adenocarcinoma of the esophagogastric junction undergoing Cheng's GIRAFFE(®) reconstruction after proximal gastrectomy].

Objective: To investigate the functional outcomes and postoperative complications of Cheng's GIRAFFE reconstruction after proximal gastrectomy. Methods: A descriptive case series study was conducted. Clinical data of 100 patients with adenocarcinoma of the esophagogastric junction who underwent Cheng's GIRAFFE reconstruction after proximal gastrectomy in Cancer Hospital of University of Chinese Academy of Sciences (64 cases), Zhejiang Provincial Hospital of Chinese Medicine (24 cases), Lishui Central Hospital (10 cases), Huzhou Central Hospital (1 case) and Ningbo Lihuili Hospital (1 case) from September 2017 to June 2021 were retrospectively analyzed. Of 100 patients, 64 were males and 36 were females; the mean age was (61.3 ± 11.1) years and the BMI was (22.7±11.1) kg/m(2). For TNM stage, 68 patients were stage IA, 24 were stage IIA and 8 were stage IIB. Postoperative functional results and postoperative complications of radical gastrectomy with Giraffe reconstruction were analyzed and summarized. Gastroesophageal reflux disease questionnaire (RDQ) score and postoperative endoscopy were used to evaluate the occurrence of reflux esophagitis and its grade (grade N, grade A, grade B, grade C, and grade D from mild to severe reflux). The continuous data conforming to normal distribution were expressed as (mean ± standard deviation), and those with skewed distribution were presented as median (Q1, Q3). Results: All the 100 patients successfully completed R0 resection, including 77 patients undergoing laparoscopic surgery and 23 patients undergoing laparotomy. The Giraffe anastomosis time was (38.6±14.0) min; the blood loss was (73.0±18.4) ml; the postoperative hospital stay was 9.5 (8.2, 13.0) d; the hospitalization cost was (6.0±0.3) ten thousand yuan. Fourteen cases developed perioperative complications (14.0%), including 7 cases of pleural effusion or pneumonia, 3 cases of anastomotic leakage, 2 cases of gastric emptying disorder, 1 case of gastrointestinal hemorrhage and 1 case of anastomotic stenosis, who were all improved and discharged after symptomatic management. Patients were followed up for (33.3±1.6) months. Eight patients were found to have reflux symptoms by RDQ scale six months after surgery, and 11 patients (11/100,11.0%) were found to have reflux esophagitis by gastroscopy, including 6 in grade A, 3 in grade B, and 2 in grade C. All the patients could control their reflux symptoms with behavioral guidance or oral PPIs. Conclusion: Cheng's GIRAFFE reconstruction has good anti-reflux efficacy and gastric emptying function; it can be one of the choices of reconstruction methods after proximal gastrectomy.

[Functional evaluation after function-preserving gastrectomy].

With the increase of people's health awareness and the progress of medical diagostic technology in recent years, the diagnosis rate of early gastric cancer is increasing year by year. Although radical surgery has good efficacy, how to maximize the preservation of the normal anatomy and function of the stomach and improve the quality of life of patients in the pursuit of radical surgery has become a more important issue in the treatment of early gastric cancer. Under the condition of ensuring radical lymph node dissection, function-preserving gastrectomy can fully preserve gastric function by reducing the resection extent and preserving the pylorus and the vagus nerve, which has advantage of improving quality of life and has great potential in the treatment of early gastric cancer. However, there is no functional evaluation standard for function-preserving gastrectomy at present. Most of the patients are evaluated by quality of life scale, which is relatively subjective. Even though the evaluation of endoscopy, hematology and other objective means can indicate the benefit degree in quality of life brought by functional reconstruction, the evidence level is limited. Therefore, this paper discusses the research status of function-preserving gastrectomy evaluation, postoperative complications, postoperative nutritional status, auxiliary examination and other items in the evaluation of gastric function, and analyzes the prospects of research direction in this field.

[Preliminary efficacy analysis of Cheng's Giraffe reconstruction after proximal gastrectomy in adenocarcinoma of esophagogastric junction].

Objective: To investigate the safety and feasibility of proximal partial gastrectomy with Cheng's Giraffe esophagogastric reconstruction for the treatment of early Siewert II adenocarcinoma of esophagogastric junction (AEG). Methods: Indication of Cheng's Giraffe esophagogastric reconstruction: (1) Siewert II AEG or Siewert III AEG with diameter < 4 cm; (2) preoperative staging as cT1-2N0M0. A descriptive case series study was carried out. Clinical data of 34 patients with Siewert II AEG undergoing proximal partial gastrectomy and Cheng's Giraffe esophagogastric reconstruction at Department of Abdominal Surgery of Zhejiang Cancer Hospital and Department of Gastrointestinal Surgery, The First Affiliated Hospital of Zhejiang University of Traditional Chinese Medicine from February to July 2018 were retrospectively collected and analyzed, including 14 cases in IA stage, 11 cases in IIA stage and 8 cases in IIB stage. Brief procedure of Cheng's Giraffe esophagogastric reconstruction was as follows: Firstly, 12 cm long tubular stomach was formed by longitudinal incision 4 cm away from the great curvature of the stomach. Secondly, the gastric fundus and His angle were formed. Finally, the distance from His angle to esophagal-tubular gastric anastomosis should be more than 5 cm. The reflux disease questionare (RDQ) scores, radionuclide gastric emptying scintigraphy, and 24-hour multichannel intraluminal (MII)-pH monitoring technology were used to evaluate postoperative gastric emptying and gastroesophageal reflux. Result: All 34 patients successfully completed proximal partial gastrectomy with Cheng's Giraffe esophagogastric reconstruction, including 13 cases by open surgery and 21 cases by laparoscopic surgery. The operation time was (144.6±39.8) minutes, the blood loss during operation was (35.4±17.2) ml. No laparoscopic case was converted to open surgery and no postoperative complication was observed. The postoperative hospital stay was (8.4±2.5) days. The postoperative RDQ score was 4.4±3.1 one month after operation, and 3.3±2.5 six months after operation. Gastric-half emptying time was (67.0±21.5) minutes, and the residual ratio was (52.2±7.7)% in 1 hour, (36.4±3.1)% in 2 hours and (28.8±3.6)% in 3 hours at postoperative 1-month. The 24-hour MII-pH monitoring at postoperative 2-month revealed the frequency of acid reflux was (12.6±7.9) times, frequency of non-acid reflux was (19.6±9.7) times, DeMeester score was 5.8±2.9. Conclusion: Cheng's Giraffe esophagogastric reconstruction is safe and feasible in the treatment of Siewert type II AEG, and has good dynamic and anti-reflux effects.

LncRNA NEAT1/miR-1224/KLF3 contributes to cell proliferation, apoptosis and invasion in lung cancer.

OBJECTIVE: The aim of this study was to detect the relationship between long-chain non-coding RNA (lncRNA) NEAT1 and microRNA-1224 (miR-1224) in lung cancer and to explore its underlying mechanism. MATERIALS AND METHODS: The expression levels of lncRNA NEAT1 and miR-1224 in lung cancer tissues and cells were detected by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). The interaction between lncRNA NEAT1 with miR-1224, miR-1224, and KLF3 was detected by Dual-Luciferase Reporter Gene Assay. MTT 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide and flow cytometry were used to detect the changes in the proliferative and apoptosis abilities of lung cancer cells after silencing lncRNA NEAT1 or up-regulating miR-1224, respectively. RESULTS: Compared with adjacent normal tissues, lncRNA NEAT1 was significantly up-regulated, while miR-1224 was significantly down-regulated in lung cancer tissues. LncRNA NEAT1 could specifically bind to the 3'UTR of miR-1224 and regulate its expression. The inhibition of lncRNA NEAT1 remarkably reduced the proliferation and enhanced the apoptosis of lung cancer cells. However, the upregulation of the expression of miR-1224 level could significantly inhibit proliferation and promote the apoptosis rate of lung cancer cells. Furthermore, miR-1224 could downregulate KLF3 expression by directly binding to its 3'UTR. CONCLUSIONS: LncRNA NEAT1 can sponge the expression of miR-1224, thereby affecting the proliferation and apoptosis of lung cancer.

MicroRNA-488 regulates diabetic nephropathy via TGF-ß1 pathway.

OBJECTIVE: The aim of this study was to clarify the biological roles of microRNA-488 and transforming growth factor ß1 (TGF-ß1) pathway in the occurrence and progression of diabetic nephropathy (DN). MATERIALS AND METHODS: Quantitative Real Time-Polymerase Chain Reaction (qRT-PCR) was used to detect the expressions of microRNA-488, fibrinogen factors coII, coIIV, and fibronectin (FN) in Human mesangial cells (HMCs) with high-glucose or low-glucose treatment. After transfection of microRNA-488 mimics or inhibitor, expression levels of coII, coIIV, and FN in HMCs were determined by qRT-PCR and Western blot. Their expressions in HMC cells treated with different doses of TGF-ß1 at different time points were also detected. Finally, we evaluated the potential influence of microRNA-488 on TGF-ß1-induced fibrosis of HMC cells by qRT-PCR. RESULTS: Compared with low-glucose treatment, the expression of microRNA-488 markedly increased in HMCs treated with high-glucose, as well as coII, coIIV, and FN. Overexpression of microRNA-488 remarkably upregulated mRNA and protein levels of coII, coIIV, and FN, whereas microRNA-488 knockdown downregulated their levels. Expression levels of microRNA-488, coII, coIIV, and FN gradually upregulated with the increase of TGF-ß1 dose and treatment duration. CONCLUSIONS: MicroRNA-488 regulates the development of diabetic nephropathy-induced fibrosis by TGF-ß1 pathway.

Dose dependency PM2.5 aggravated airway inflammation in asthmatic mice via down-regulating expression of ITGB4.

OBJECTIVE: We aimed to investigate whether PM2.5 has the potential to exacerbate neutrophil airway inflammation and to analyze the underlying mechanisms. MATERIALS AND METHODS: The high-volume air sampler (Laoying 2033B, Qingdao, China) was used to collect PM2.5 from January 01, 2016 to December 21, 2016 in Yantai, Shandong Province, China. BALB/c mice were divided into the following four groups: control group, ovalbumin (OVA) group, low-dose PM2.5 group and high-dose PM2.5 group. Mice except for control group were sensitized and challenged by OVA, and those in low-dose PM2.5 group and high-dose PM2.5 group were intranasally administered by PM2.5 suspension. Airway responsiveness of mice was measured. Enzyme-linked immunosorbent assay (ELISA) kit was used to evaluate the expressions of interleukin 17 (IL-17) and tumor necrosis factor-α (TNF-α) in bronchoalveolar lavage fluid (BALF) and serum samples. Cell counting in BALF and histological examination were measured to explore PM2.5-induced airway inflammation. Protein expression of Integrin ß4 (ITGB4) was assessed by Western blot. RESULTS: Airway hyperresponsiveness (AHR) exacerbated in PM2.5 exposed asthmatic mice in progressively increased doses of acetylcholine chloride (ACH). Levels of IL-17 and TNF-αin BALF and serum increased significantly in PM2.5 groups compared with other groups with significant differences between two PM2.5 groups. PM2.5 exposure exacerbated inflammatory cell infiltration and mucus secretion in airways of asthmatic mice. Percentage of neutrophils in PM2.5 groups was significantly higher in dose-dependent manner. OVA and PM2.5 co-exposure inhibited the expression of ITGB4. In particular, ITGB4 expression in mice of high-dose PM2.5 group was significantly lowered than the low-dose PM2.5 group. CONCLUSIONS: We showed that PM2.5 exposure exacerbates neutrophil airway inflammation in asthmatic mice though up-regulating expressions of IL-17 and TNF-α but down-regulating the expression of ITGB4.

Long non-coding RNA CACNA1G-AS1 promotes cell migration, invasion and epithelial-mesenchymal transition by HNRNPA2B1 in non-small cell lung cancer.

OBJECTIVE: In recent years, long non-coding RNAs (lncRNAs) have been identified to participate in tumor progression. The purpose of this study was to investigate the role of CACNA1G-AS1 in non-small cell lung cancer (NSCLC). PATIENTS AND METHODS: Quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) was used to detect the CACNA1G-AS1 expression level in 122 pairs of NSCLC and para-carcinoma normal tissue samples as well as in NSCLC cell lines. Moreover, the relationship of clinical pathological features with CACNA1G-AS1 was analyzed. Functional experiment cell lines were established using lentivirus and siRNA to study the effects of CACNA1G-AS1 on cell invasion and migration abilities. Several epithelial-mesenchymal transition (EMT) markers were measured using Western blotting. The expression level of HNRNPA2B1 was analyzed to further investigate the mechanism. RESULTS: The expression level of CACNA1G-AS1 in NSCLC tissues was significantly higher than that in para-carcinoma normal tissues, and the expression of CACNA1G-AS1 was higher in NSCLC cell lines than that in normal BEAS-2B cells. The higher CACNA1G-AS1 level was relative to more lymph node metastasis and distant metastasis. Function experiments revealed that CACNA1G-AS1 promoted cell invasion and migration. Also, CACNA1G-AS1 over-expression increased EMT in NSCLC cells. Besides, HNRNPA2B1 was regulated by CACNA1G-AS1 in NSCLC cells. CONCLUSIONS: CACNA1G-AS1 was identified as an oncogene in NSCLC for the first time, and could promote cell invasion, migration and EMT via increasing HNRNPA2B1 expression, providing a novel target for the biological therapy and prevention.

Caffeic acid n-butyl ester-triggered necrosis-like cell death in lung cancer cell line A549 is prompted by ROS mediated alterations in mitochondrial membrane potential.

OBJECTIVE: The aim of the present study was to evaluate the anticancer activity of caffeic acid n-butyl ester against lung cancer cell line A549 and to investigate the underlying mechanism. MATERIALS AND METHODS: IC50 was determined by MTT assay. Fluorescent probes DCFH-DA, Indo 1/AM, DiOC6 were used to determine ROS, Ca2+, and mitochondrial membrane potential (ΔΨm). ATP levels were determined by using ATP liteTM kit. DNA damage was investigated by DAPI and comet assays. Protein expression was investigated by Western blotting. RESULTS: Caffeic acid n-butyl ester exhibited lowest IC50 of 25 µM against lung A549 cell line. Caffeic acid n-butyl ester reduced the cell viability of A549 cells concentration and time-dependently. It also augmented the discharge of ROS and Ca2+ and lessened the mitochondrial membrane potential (ΔΨm) and ATP levels in A549 cells. Additionally, caffeic acid n-butyl ester also prompted DNA damage in A549 cell line. Notably, caffeic acid n-butyl ester-stimulated the cytochrome c release only and exhibited no effect on the expression of apoptosis-related protein levels such as caspase-3, caspase-8, and Apaf-1. DISCUSSION: Caffeic acid n-butyl ester exhibited significant anticancer activity against lung cancer cell line A549. However, the anticancer activity was not due to apoptosis as no significant change was observed in the expression of apoptosis-related proteins. The anticancer activity of caffeic acid n-butyl ester may be attributed to necrosis-like cell death prompted by ROS-mediated alterations in ΔΨm. CONCLUSIONS: Taken together, we conclude that caffeic acid n-butyl ester-induced A549 cells death displayed a cellular pattern characteristic of necrotic cell death and not of apoptosis.

TNFα-activated mesenchymal stromal cells promote breast cancer metastasis by recruiting CXCR2+ neutrophils.

Mesenchymal stromal cells (MSCs) tend to infiltrate into tumors and form a major component of the tumor microenvironment. Our previous work demonstrated that tumor necrosis factor α (TNFα)-activated MSCs significantly promoted tumor growth. However, the role of TNFα-treated MSCs in tumor metastasis remains elusive. Employing a lung metastasis model of murine breast cancer, we found that TNFα-activated MSCs strikingly enhanced tumor metastasis compared with normal MSCs. We analyzed the chemokine profiles and found that the expression of CCL5, CCR2 and CXCR2 ligands were enhanced in TNFα-activated MSCs. Using genetic or pharmacological strategies to inhibit CCL5 or CCR2, we demonstrated that CCL5 and CCR2 ligands were indispensable in supporting TNFα-activated MSCs to promote tumor metastasis. Analysis of immune cells revealed that CXCR2 ligands (CXCL1, CXCL 2 and CXCL5) expressed by TNFα-activated MSCs efficiently recruited CXCR2+ neutrophils into tumor. These neutrophils were responsible for the pro-metastatic effect of MSCs since inhibition of this chemotaxis abolished increased neutrophil recruitment and tumor metastasis. The interaction between neutrophils and tumor cells resulted in markedly elevated metastasis-related genes by tumor cells, including CXCR4, CXCR7, MMP12, MMP13, IL-6 and TGFß. Importantly, in IL8high human breast cancer samples, we also observed similar alterations of gene expression. Collectively, our findings demonstrate that TNFα-activated MSCs promote tumor metastasis via CXCR2+ neutrophil recruitment.

Downregulation of CXCL12 in mesenchymal stromal cells by TGFß promotes breast cancer metastasis.

Mesenchymal stromal cells (MSCs) are one of major components of the tumour microenvironment. Recent studies have shown that MSC tumour residence and their close interactions with inflammatory factors are important factors that affect tumour progression. Among tumour-associated inflammatory factors, transforming growth factor ß (TGFß) is regarded as a key determinant of malignancy. By employing a lung metastasis model of a murine breast cancer, we show here that the prometastatic effect of MSCs was dependent on their response to TGFß. Interestingly, we found that MSC-produced CXCL12, an important chemokine in tumour metastasis, was markedly inhibited by TGFß. Furthermore, silencing of CXCL12 in TGFß-unresponsive MSCs restored their ability to promote tumour metastasis. We found that 4T1 breast cancer cells expressed high levels of CXCR7, but not of CXCR4, both of which are CXCL12 receptors. In presence of CXCL12, CXCR7 expression on tumour cells was decreased. Indeed, when CXCR7 was silenced in breast cancer cells, their metastatic ability was inhibited. Therefore, our data demonstrated that sustained expression of CXCL12 by MSCs in the primary tumour site inhibits metastasis through reduction of CXCR7, while, in the presence of TGFß, this CXCL12 effect of MSCs on tumour cells is relieved. Importantly, elevated CXCR7 and depressed CXCL12 expression levels were prominent features of clinical breast cancer lesions and were related significantly with poor survival. Our findings reveal a novel mechanism of MSC effects on malignant cells through which crosstalk between MSCs and TGFß regulates tumour metastasis.

Tumour cell-derived exosomes endow mesenchymal stromal cells with tumour-promotion capabilities.

Mesenchymal stromal cells (MSCs) are a major component of the tumour microenvironment. A plethora of elegant studies focusing on tumour-derived MSCs have shown that they, unlike normal MSCs in other tissue, exhibit a strong ability to promote tumour progression. However, the mechanisms underlying the conversion of normal MSCs into tumour-associated MSCs are unknown. We report here a critical role of tumour cell-derived exosomes in endowing bone marrow-derived MSCs (BM-MSCs) with a tumour-favourable phenotype. Tumour cell-derived exosomes affected neither the growth factor production nor the immunosuppressive property of MSCs; rather, they endowed MSCs with a strong ability to promote macrophage infiltration into B16-F0 melanoma or EL-4 lymphoma. Ablation of macrophages by clodronate liposome administration reversed the tumour-promoting effect of MSCs educated by tumour cell-derived exosomes (TE-MSCs) on the tumour growth. By comparing the chemokine profile of BM-MSCs with that of TE-MSCs, we found that TE-MSCs produced a large amount of CCR2 ligands, CCL2 and CCL7, which are responsible for macrophage recruitment. CCR2-specific inhibitor was found to block the tumour-promoting effect of TE-MSCs. Thus, our investigations demonstrated that tumour cell-derived exosomes confer BM-MSCs the ability to enhance tumour growth. Therefore, we uncovered a novel mechanism underlying the conversion of normal MSCs to tumour-associated MSCs.

Studies on anti-tumour activities of pseudolaric acid-B (PLAB) and its mechanism of action.

Pseudolaric acid-B (PLAB), a diterpene acid, was isolated from the root and trunk barks of Pseudolarix kaempferi. It showed antifungal and anti-fertility effects as well as cytotoxic activities in previous studies. The present study investigates cytotoxic activity on cultured human cancer cells, inhibition on the growth of transplantable tumours in mice and the mechanism of these actions. The experimental results showed that PLAB had potent cytotoxic effects on cancer cells derived from different tissues. MTT assay showed that its IC50 towards these tumour cells was 0.17 to 5.20 micromol/L, and towards one normal human kidney proximal tubular epithelial cell (HKC) was 5.77 micromol/L. Furthermore, the results of cell growth curve and colony formation of cancer cells matched the above results. The results in vivo demonstrated that PLAB significantly inhibited the growth of transplantable tumours, such as Lewis lung cancer and hepatocarcinoma 22 (H22) in mice. The inhibitory rate to H22 was 14.4% and 40.1%, and to Lewis lung cancer reached 39.1% and 47.0%, when PLAB was given by intraperitoneal injection (i.p.) at a dose of 30 mg/kg/day and 60 mg/kg/day for 10 days, respectively. It is suggested that PLAB also showed obvious anticancer activity in vivo. Inducing apoptosis by PLAB in HeLa cells was assessed by various morphological and biochemical characteristics, including cell shrinkage, chromatin condensation, membrane blebbing, formation of apoptotic bodies, and internucleosomal DNA fragmentation. A typical 'sub-G1 peak' was also checked through flow cytometry. These results were accompanied by up-regulating P53, down-regulating Bcl-2 and activating Caspase-3, which was revealed by Western blotting. PLAB also caused cell cycle arrest to G2/M phase in a dose-dependent manner. The experiments suggest that PLAB is a new potent anti-tumour agent.