The efficacy and safety of short-course radiotherapy followed by sequential chemotherapy and Cadonilimab for locally advanced rectal cancer: a protocol of a phase II study.

BACKGROUND: For patients with locally advanced rectal cancer (LARC), total neoadjuvant therapy (TNT), namely, intensifying preoperative treatment through the integration of radiotherapy and systemic chemotherapy before surgery, was commonly recommended as the standard treatment. However, the risk of distant metastasis at 3 years remained higher than 20%, and the complete response (CR) rate was less than 30%. Several clinical trials had suggested a higher complete response rate when combining single-agent immunotherapy with short-course radiotherapy (SCRT). The CheckMate 142 study had shown encouraging outcomes of dual immunotherapy and seemingly comparable toxicity for CRC compared with single-agent immunotherapy in historical results. Therefore, dual immunotherapy might be more feasible in conjunction with the TNT paradigm of SCRT. We performed a phase II study to investigate whether the addition of a dual immune checkpoint inhibitor bispecific antibody, Cadonilimab, to SCRT combined with chemotherapy might further increase the clinical benefit and prognosis for LARC patients. METHODS: This single-arm, multicenter, prospective, phase II study included patients with pathologically confirmed cT3-T4N0 or cT2-4N + rectal adenocarcinoma with an ECOG performance score of 0 or 1. Bispecific antibody immunotherapy was added to SCRT combined with chemotherapy. Patients enrolled would be treated with SCRT (25 Gy in five fractions over 1 week) for the pelvic cavity, followed by 4 cycles of CAPOX or 6 cycles of mFOLFOX and Cadonilimab. The primary endpoint was the CR rate, which was the ratio of the pathological CR rate plus the clinical CR rate. The secondary endpoints included local-regional control, distant metastasis, disease-free survival, overall survival, toxicity profile, quality of life and functional outcome of the rectum. To detect an increase in the complete remission rate from 21.8% to 40% with 80% power, 50 patients were needed. DISCUSSION: This study would provide evidence on the efficacy and safety of SCRT plus bispecific antibody immunotherapy combined with chemotherapy as neoadjuvant therapy for patients with LARC, which might be used as a candidate potential therapy in the future. TRIAL REGISTRATION: This phase II trial was prospectively registered at ClinicalTrials.gov, under the identifier NCT05794750.

Toxic effects of nanopolystyrene and cadmium on the intestinal tract of the Chinese mitten crab (Eriocheir sinensis).

Nanopolystyrene (NP) and cadmium (Cd) are ubiquitous contaminants in aquatic systems. The present study aimed to investigate the toxic effects of exposure to ambient concentrations of NP and/or Cd on the intestinal tract of the Chinese mitten crab (Eriocheir sinensis). Exposure to NP and/or Cd induced oxidative stress, as evidenced by a significant increase in lipid peroxide content (LPO), total antioxidant capacity (T-AOC), and peroxidase activity (POD), and significant decreases in superoxide dismutase (SOD) and glutathione peroxidase (GSH-PX) activities in E. sinensis. In addition, exposure to NP and/or Cd imbalanced the homeostasis of the intestinal microbiota, as demonstrated by the significantly increased abundance of Spiroplasma. Transcriptomic and metabolomic analyses were performed to investigate the mechanisms underlying intestinal toxicity. Our results showed that ferroptosis, ABC transporters, phosphotransferase system, apoptosis, and leukocyte transendothelial migration were disturbed after exposure to NP and/or Cd. In particular, Cd exposure affected mucin type O-glycan biosynthesis, purine metabolism, and neuroactive ligand-receptor interaction. Intriguingly, co-exposure to NP and Cd might mitigate intestinal toxicity by decreasing oxidative stress and affecting these pathways. Taken together, our study clearly demonstrates that exposure to NP and/or Cd at environmentally relevant concentrations causes intestinal toxicity in E. sinensis.

The mechanism of monobutyl phthalate -induced ferroptosis via TNF/IL6/STAT3 signal pathway in TM-3 cells.

As a common environmental endocrine disruptor, monobutyl phthalate (MBP) has been connected to reports of ROS accumulation, sperm destruction and reproductive damage. However, the specific mechanism of reproductive injury caused by MBP remains uncertain. Ferroptosis is a non-apoptotic, controlled oxidative damage-related cell death that is usually connected with reactive oxygen species and lipid peroxidation. In this work, to evaluate the mechanism of MBP-induced ferroptosis in reproductive damage, bioinformation analysis and experimental validation were used. Based on bioinformatics analysis, the interleukin-6 (IL-6) and signal transducer and activator of transcription 3 (STAT3) genes may be involved in the tumor necrosis factor (TNF) signaling pathway, which controls inflammation. Experimental study validated the significance of IL6 and STAT3 in MBP-induced ferroptosis. Western blotting and quantitative real-time PCR revealed that Acyl-CoA Synthetase Long Chain Family Member 4 (ACSL4), Tumor necrosis factor-α (TNF-α), IL6, and STAT3 were all elevated with treatment of MBP, but Glutathione peroxidase 4 was significantly decreased. To determine the participation of IL6/STAT3, we added the ferroptosis inhibitor Ferrastain-1 (Fer-1) and the IL6/STAT3 pathway inhibitor Angoline. In conclusion, we found that MBP induced ferroptosis in TM3 cells to damage male reproductive system through the TNF/IL6/STAT signal pathway, resulting in lipid peroxidation and iron metabolite degradation.

Targeting ovarian cancer stem cells: a new way out.

Ovarian cancer (OC) is the most lethal gynecological malignancy due to tumor heterogeneity, the lack of reliable early diagnosis methods and the high incidence of chemoresistant recurrent disease. Although there are developments in chemotherapies and surgical techniques to improve the overall survival of OC patients, the 5-year survival of advanced OC patients is still low. To improve the prognosis of OC patients, it is important to search for novel therapeutic approaches. Cancer stem cells (CSCs) are a subpopulation of tumor cells that participate in tumor growth, metastasis and chemoresistance. It is important to study the role of CSCs in a highly heterogeneous disease such as OC, which may be significant to a better understanding of the oncogenetic and metastatic pathways of the disease and to develop novel strategies against its progression and platinum resistance. Here, we summarized the current findings about targeting methods against ovarian cancer stem cells, including related signaling pathways, markers and drugs, to better manage OC patients using CSC-based therapeutic strategies.

The prognostic value of MRI-detected extramural vascular invasion (mrEMVI) for rectal cancer patients treated with neoadjuvant therapy: a meta-analysis.

OBJECTIVES: The purpose of this meta-analysis was to evaluate the prognostic value of MRI-detected extramural vascular invasion (mrEMVI) and mrEMVI after neoadjuvant therapy (ymrEMVI) in rectal cancer patients receiving neoadjuvant therapy. METHODS: A systematic search of the PubMed, Web of Science, Embase, and Cochrane Library databases was carried out up to June 2020. Studies that evaluated mrEMVI, used treatment with neoadjuvant therapy, and reported survival were included. The time-to-event outcomes (OS and DFS rates) are expressed as hazard ratios (HRs) with 95% confidence intervals (CIs). If the HR was not reported in the study, it was calculated from the survival curve using methods according to Parmar's recommendation. The Newcastle-Ottawa scale was used to assess the methodological quality of the studies included in the meta-analysis. RESULTS: A total of 2237 patients from 11 studies were included, and the pooled analysis of the overall results from eight studies showed that patients who were mrEMVI positive at baseline had significantly worse disease-free survival (DFS) (random-effects model: HR = 2.50 [1.84, 3.14]; Z = 5.83, p < 0.00001). The pooled analysis of the overall results from six studies showed that patients who were ymrEMVI positive following neoadjuvant therapy had significantly worse DFS (random-effects model: HR = 2.24 [1.73, 2.90], Z = 6.12, p < 0.00001). Patients with mrEMVI positivity at baseline were also associated with worse overall survival (OS) (random-effects model: HR = 1.93 [1.36, 2.73]; Z = 3.71, p < 0.00001). CONCLUSION: mrEMVI and ymrEMVI positivity are poor prognostic factors for rectal cancer patients treated with neoadjuvant therapy. The precise evaluation of EMVI may contribute to designing individualised treatments and improving patient outcomes. KEY POINTS: • Extramural vascular invasion (EMVI) is a prognostic factor for rectal cancer. • MRI can be used to evaluate EMVI status before (mrEMVI) and after neoadjuvant therapy (ymrEMVI). • The evaluation of mrEMVI and ymrEMVI in neoadjuvant therapy would provide an early assessment of patient prognosis.

Degree and site of chromosomal instability define its oncogenic potential.

Most human cancers are aneuploid, due to a chromosomal instability (CIN) phenotype. Despite being hallmarks of cancer, however, the roles of CIN and aneuploidy in tumor formation have not unequivocally emerged from animal studies and are thus still unclear. Using a conditional mouse model for diverse degrees of CIN, we find that a particular range is sufficient to drive very early onset spontaneous adenoma formation in the intestine. In mice predisposed to intestinal cancer (ApcMin/+), moderate CIN causes a remarkable increase in adenoma burden in the entire intestinal tract and especially in the distal colon, which resembles human disease. Strikingly, a higher level of CIN promotes adenoma formation in the distal colon even more than moderate CIN does, but has no effect in the small intestine. Our results thus show that CIN can be potently oncogenic, but that certain levels of CIN can have contrasting effects in distinct tissues.

Prognostic role of secreted protein acidic and rich in cysteine in patients with solid tumors.

OBJECTIVES: To analyze the heterogeneous functions of secreted protein acidic and rich in cysteine (SPARC) from different origins and in different tumor microenvironments with the purpose of determining its clinical significance. Methods: The PubMed, CINAHL, Cochrane, Web of Science and Embase databases were utilized. Studies that focused on the effects of SPARC expression on solid tumor progression and clinical implications were used. The different outcomes including overall survival and disease-free survival were analyzed to evaluate their relations with tumor- and stroma-derived SPARC expression. Results: A total of 26 studies including 5,939 patients were enrolled in the present meta-analysis. Tumor-derived SPARC overexpression was significantly related with poor overall survival (hazard ratio: 1.478; 95% CI: 1.143-1.910; p=0.003), and a similar tendency was also observed in disease-free survival (hazard ratio: 1.476; 95% CI: 0.993-2.195; p=0.054). However, the hazard ratios for overall survival and disease-free survival did not present a statistical trend in stromal SPARC overexpression. Tumor type subgroup analysis revealed marked heterogeneity among outcomes. In pancreatic cancer, SPARC overexpression in the stroma was significantly associated with poorer overall survival and disease-free survival. In colorectal cancer, SPARC overexpression in the stroma was associated with better disease-free survival. Conclusion: For the majority of solid tumors, SPARC in cancer cells may be an unfavorable indicator for long-term survival for patients. As for stromal expression, SPARC indicates a poorer prognosis in pancreatic cancer, but a better disease-free survival in colorectal cancer. Secreted protein acidic and rich in cysteine might be a potential biomarker for solid tumor prognosis.

Cancer antigen-125 levels correlate with pleural effusions and COPD-related complications in people living at high altitude.

Chronic obstructive pulmonary disease (COPD) is the most frequently encountered progressive lung disease in clinical practice. This study sought to determine the predictive ability of the tumor biomarker cancer antigen-125 (CA-125) in the identification of COPD in a cohort of 284 patients with COPD living at high altitude (with an average elevation of over 2500 m).Patients were classified by pleural effusion volumes into 4 categories and serum CA-125 concentrations were measured in each category. The analyses revealed that CA-125 concentrations were positively and significantly correlated with pleural effusion volume. CA-125 concentrations were also positively correlated with pulmonary heart disease and acute exacerbations of COPD, and negatively correlated with pulmonary hypertension.The study evidence suggests that serum CA-125 concentrations are positively correlated with the risk of pleural effusions among patients with COPD living in high-altitude areas, and that CA-125 concentrations are also correlated with pulmonary heart disease, acute exacerbations, and pulmonary hypertension.

Pathology and genetics of hereditary colorectal cancer.

Colorectal cancer (CRC) accounts for over 8% of all deaths annually worldwide. Between 2 and 5% of all CRCs occur due to inherited syndromes, including Lynch syndrome, familial adenomatous polyposis, MUTYH-associated polyposis, Peutz-Jeghers syndrome, juvenile polyposis and Cowden/PTEN hamartoma syndrome. In addition, serrated polyposis is a clinically defined condition characterised by multiple colorectal serrated polyps and an increased risk of CRC but the genetics are not known. In most hereditary CRC syndromes, polyps undergo carcinogenesis, but the exact route to carcinoma seems to differ between the conditions. Discovery of the key germline mutations in these syndromes has been instrumental to our understanding of the underlying molecular mechanisms of colorectal carcinogenesis. This review summarises the genetic and pathological alterations in hereditary CRC syndromes.

Longitudinal analysis of colon crypt stem cell dynamics in sulindac treated Familial Adenomatous Polyposis patients.

The non-steroidal anti-inflammatory drug sulindac decreases size and number of adenomas after 4-6 months of treatment for familial adenomatous polyposis (FAP) patients. However, the underlying mechanism remains unknown. As stem cells are thought to be the tumor precursor cells, visualizing their behavior is crucial for monitoring tumor progression. Increased tag diversity in inactive genes is indicative of a protracted clonal evolution and consequently, increased risk for tumor formation. Therefore, the effect of sulindac on stem cell dynamics was studied. Normal appearing single crypts were laser microdissected in placebo- and sulindac- treated FAP patient tissue after which the methylation patterns were visualized by Next Generation Sequencing. A significant difference in tag diversity over time was found in the sulindac group compared to the placebo group (*p = 0.018), indicative of a shortened clonal evolution treated sulindac. The rate of change in tag diversity over time was correlated with polyp number change over time. No significant difference over time was observed in the percent methylation when comparing placebo vs sulindac. In conclusion, daily sulindac administration in FAP patients significantly altered colorectal stem cell dynamics, which might explain the chemopreventive action of this drug indicating that tag diversity may be used as a predictive biomarker.

Inflammatory microenvironment contributes to epithelial-mesenchymal transition in gastric cancer.

Gastric cancer (GC) is the fifth most common malignancy in the world. The major cause of GC is chronic infection with Helicobacter pylori (H. pylori). Infection with H. pylori leads to an active inflammatory microenvironment that is maintained by immune cells such as T cells, macrophages, natural killer cells, among other cells. Immune cell dysfunction allows the initiation and accumulation of mutations in GC cells, inducing aberrant proliferation and protection from apoptosis. Meanwhile, immune cells can secrete certain signals, including cytokines, and chemokines, to alter intracellular signaling pathways in GC cells. Thus, GC cells obtain the ability to metastasize to lymph nodes by undergoing the epithelial-mesenchymal transition (EMT), whereby epithelial cells lose their epithelial attributes and acquire a mesenchymal cell phenotype. Metastasis is a leading cause of death for GC patients, and the involved mechanisms are still under investigation. In this review, we summarize the current research on how the inflammatory environment affects GC initiation and metastasis via EMT.

Stem cell dynamics and pretumor progression in the intestinal tract.

Colorectal carcinogenesis is a process that follows a stepwise cascade that goes from the normal to an invisible pretumor stage ultimately leading to grossly visible tumor progression. During pretumor progression, an increasing accumulation of genetic alterations occurs, by definition without visible manifestations. It is generally thought that stem cells in the crypt base are responsible for this initiation of colorectal cancer progression because they are the origin of the differentiated epithelial cells that occupy the crypt. Furthermore, they are characterized by a long life span that enables them to acquire these cumulative mutations. Recent studies visualized the dynamics of stem cells both in vitro and in vivo. Translating this work into clinical applications will contribute to the evaluation of patients' predisposition for colorectal carcinogenesis and may help in the design of preventive measures for high-risk groups. In this review, we outline the progress made in the research into tracing stem cell dynamics. Further, we highlight the importance and potential clinical value of tracing stem cell dynamics in pretumor progression.

CCR7 enhances TGF-ß1-induced epithelial-mesenchymal transition and is associated with lymph node metastasis and poor overall survival in gastric cancer.

CCR7 is a G protein-coupled chemokine receptor. In this study, we used immunohistochemistry with tissue microarrays to measure CCR7 expression in tumor specimens from 122 patients with gastric cancer. We show that CCR7 expression is associated with lymph node metastasis (P = 0.022) and overall survival (OS; P = 0.025), and is an independent factor associated with poorer overall survival (P = 0.032). The CCR7 mechanism was predicted based on bioinformatic analysis and verified in gastric cancer cell lines and primary tumor samples. The data show that CCR7 contributes to TGF-ß1-induced epithelial-mesenchymal transition (EMT) and that the effects of TGF-ß1 are inhibited by a CCR7 neutralizing antibody or a NF-κB inhibitor. Increased TGF-ß1 expression was accompanied by nuclear localization of NF-κB-p65 and higher levels of the mesenchymal marker vimentin in human gastric cancer samples. We conclude that the CCR7 axis mediates TGF-ß1-induced EMT via crosstalk with NF-κB signaling, facilitating lymph node metastasis and poorer overall survival in patients with gastric cancer. These findings suggest CCR7 is a novel prognostic indicator and a potential target for gastric cancer therapy.

Chemokines and their receptors play important roles in the development of hepatocellular carcinoma.

The chemokine system consists of four different subclasses with over 50 chemokines and 19 receptors. Their functions in the immune system have been well elucidated and research during the last decades unveils their new roles in hepatocellular carcinoma (HCC). The chemokines and their receptors in the microenvironment influence the development of HCC by several aspects including: inflammation, effects on immune cells, angiogenesis, and direct effects on HCC cells. Regarding these aspects, pre-clinical research by targeting the chemokine system has yielded promising data, and these findings bring us new clues in the chemokine-based therapies for HCC.

Lower serum soluble-EGFR is a potential biomarker for metastasis of HCC demonstrated by N-glycoproteomic analysis.

Hepatocellular carcinoma (HCC) is one of the most deadly cancers in the world due to its high metastatic potential. By using the isobaric tags for relative and absolute quantitation (iTRAQ)-based quantitative N-glycoproteomic analysis, 26 differentially expressed serum glycoproteins derived from defined stages in orthotopic xenograft tumor model were identified. Among them, expression level of soluble EGFR (sEGFR) was verified in HCC cell lines. We found that non-metastasis HCC cell lines express significantly more sEGFR than HCC cell lines with metastasis potential both in cell lysates and culture media. Serum samples from 28 non-metastatic HCC patients and 28 metastatic HCC patients were assayed. Compared with the non-metastatic HCC group, serum level of sEGFR in metastatic HCC group was statistically lower (p<0.01). All these results provide evidence that sEGFR is a potential candidate for metastasis-associated biomarkers of HCC. The related molecular mechanism deserves to be further explored.

Combined treatment of amyloid-ß1₋42-stimulated bone marrow-derived dendritic cells plus splenocytes from young mice prevents the development of Alzheimer's disease in APPswe/PSENldE9 mice.

Anti-amyloid-ß (Aß) immunotherapy is a potential therapeutic strategy to reduce amyloid plaques and amyloid-associated pathologies in Alzheimer's disease (AD). Immune senescence with aging has also played a crucial role in AD pathogenesis and influences the effect of anti-Aß immunotherapy. In this study, a combined treatment of Aß1₋42-bone marrow-derived dendritic cells (BMDCs) with intraperitoneal injection of splenocytes from young mice was designed as a novel immunotherapy for AD in APPswe/PSEN1de9 transgenic mice models. The results showed that the combined treatment not only elevated the level of anti-Aß antibodies but also reduced amyloid plaques in brain and finally ameliorated deterioration of spatial learning and memory in AD mice. Additionally, the results revealed an increase of CD68 positive microglial cells in the vicinity of amyloid plaques in the mouse brain, which was responsible for the enhanced phagocytosis of Aß plaques. In conclusion, the Aß1₋42-BMDCs plus splenocytes treatment improved the phagocytosis of microglia and prevented AD pathology more effectively. This combined immunotherapy provided a promising treatment in preventing the progression of AD in clinical studies in the near future.

Special role of Foxp3 for the specifically altered microRNAs in Regulatory T cells of HCC patients.

BACKGROUND: Regulatory T cells (Tregs) exhibit functional abnormalities in the context of hepatocellular carcinoma (HCC). The microRNAs (miRNAs) are identified as the key modulators in Tregs. This study was to explore whether the expression profiles of miRNAs of Tregs were different in HCC-activated Tregs and whether Foxp3 had special effects on them. METHODS: We isolated HCC-activated Tregs from mice bearing HCC and compared the expression profiles of miRNAs between HCC-activated Tregs and control Tregs by microarray. RNA interference against Foxp3 was also performed through transfection of synthetic siRNAs to Tregs for analyzing the effect of Foxp3 on the expression of miRNAs. Tregs isolated from HCC patients (n = 12) and healthy controls (n = 7) were used for validation of the differentially expressed miRNAs. Finally, bioinformatic analysis was applied to infer their possible roles. RESULTS: We found nine specifically altered miRNAs in HCC-activated Tregs from the murine model. After transfection with siRNAs against Foxp3, control Tregs showed obvious reduction of Foxp3 and five miRNAs were significantly changed; HCC-activated Tregs exhibited a slight reduction of Foxp3 with three miRNAs significantly changed. Tregs from HCC patients and healthy controls finally confirmed the up-regulation of four miRNAs (hsa-miR-182-5p, hsa-miR-214-3p, hsa-miR-129-5p and hsa-miR-30b-5p). Following bioinformatic analysis suggested these altered miRNAs would target eight important signaling pathways that could affect the functions of Tregs. CONCLUSIONS: Our studies provided the first evidence that Tregs in HCC had the specifically altered expression of miRNAs, which was affected by Foxp3. These results are useful both in finding new biomarkers and in further exploring the functions of Tregs in HCC patients.

TGF-ß1-induced expression of Id-1 is associated with tumor progression in gastric cancer.

Transforming growth factor ß1 (TGF-ß1) and inhibitor of differentiation/DNA-binding 1 (Id-1) have been shown to be associated with aggressive metastatic behavior of cancer cells in many malignant tumors. However, their role in gastric cancer (GC) has not been established. In this study, we investigated the relationship between expression of Id-1 and TGF-ß1 in GC as well as their association with GC progression. The immunohistochemical analysis of 71 human GC samples indicated that both Id-1 and TGF-ß1 were markedly upregulated in tumor tissue compared with the adjacent tissue; in addition, a significant positive correlation was found between the expression levels of Id-1 and TGF-ß1 by Pearson's correlation analysis. Furthermore, the investigation of the association of Id-1 and TGF-ß1 with patient clinical characteristics revealed that Id-1 expression was significantly correlated with tumor differentiation, while TGF-ß1 was associated with lymph node metastasis. The results were validated in vitro by using a GC cell line, AGS. The expression of Id-1 was upregulated at 24 and 48 h after the treatment with TGF-ß1, whereas it did not affect the proliferation of cells. TGF-ß1 also influenced the expression of N-cadherin and ß-catenin. Our results suggested that Id-1 and TGF-ß1 played important roles in the progression of GC, in which Id-1 might act as a downstream mediator of TGF-ß1 signaling through a regulatory mechanism involving N-cadherin and ß-catenin. The TGF-ß1/Id-1 axis might serve as a future therapeutic target for GC.

Combination of SLC administration and Tregs depletion is an attractive strategy for targeting hepatocellular carcinoma.

BACKGROUND: Secondary lymphoid tissue chemokine (SLC) is a key CC chemokine for chemotaxis of immune cells and has been an attractive candidate for anti-tumor treatments. However, among the immune cells recruited by SLC to tumors, the CD25+ Foxp3+ regulatory T cells (Tregs) compromise the anti-tumor effects. In this study, we proposed the combination therapy of intratumoral co-administration of SLC and anti-CD25 monoclonal antibodies (mAbs). We hypothesized that the intratumoral injections of SLC and depletion of Tregs would have stronger inhibition effects on the progression of hepatocellular carcinoma (HCC) in mice. METHODS: C57BL/6 mice were inoculated subcutaneously with the murine HCC cell line, and mice with visible tumors were treated intratumorally with SLC, SLC plus anti-CD25 mAbs or the control antibodies. The percentages of Tregs, effector CD8+ T cells and CD4+ T cells were checked in the tumors, lymph nodes, spleen and liver at regular intervals. The levels of intratumoral IL-12, IFN-γ, IL-10 and TGF-ß1 were evaluated. The final anti-tumor effects were measured by the tumor volume and weight as well as the intratumoral activity of MMP2 and MMP9. Bone-marrow-derived dendritic cells were used to explore the mechanisms of maturation induced by SLC in vitro. RESULTS: Our experiments showed the combination therapy significantly decreased the frequency of Tregs, and increased CD8+ T cells and CD4+ T cells at tumor sites. These alterations were accompanied by an increased level of IL-12 and IFN-γ, and decreased level of IL-10 and TGF-ß1. Unexpectedly, we observed a significantly decreased percentage of Tregs, and increased CD8+ T cells and CD4+ T cells in the lymph nodes, spleen and liver after the combination therapy. The growth and invasiveness of HCC was also maximally inhibited in the combination therapy compared with the SLC alone. Furthermore, we confirmed SLC induced the maturation of DCs via NF-κB p65 and this maturation would benefit the combination therapy. CONCLUSIONS: Our data demonstrated that intratumoral co-administration of SLC and anti-CD25 mAbs was an effective treatment for HCC, which was correlated with the altered tumor microenvironment and systemically optimized percentages of Tregs, CD8+ T cells and CD4+ T cells in peripheral immune organs.

The anti-tumor effect and increased tregs infiltration mediated by rAAV-SLC vector.

To explore the anti-tumor effect and immune mechanism mediated by a new recombinant adeno-associated virus (rAAV) encoding secondary lymphoid tissue chemokine (SLC) mature peptide gene. AAV Helper-Free system was used for rAAV-SLC package. The anti-tumor effect of SLC was detected by bearing tumor established from Hepal-6 cells both in C57BL/6J and nude mice. Flow cytometry analysis and IHC for Tumor-infiltrating T cells and CD11c+DCs were also investigated to explore the immunological mechanism. rAAV-SLC was successfully packaged in AAV293 cells and transfected Hepal-6 tumor cells at high efficiency. The anti-tumor effect was demonstrated by less tumor weight and longer survival outcome. Coincident with the anti-tumor response, local elaboration of SLC within the tumor bed elicited a heavy infiltration of CD4+, CD8+T cells and CD11c+ dendritic cells into the tumor sites. More importantly, there was higher infiltration of Foxp3+ regulatory T cells (Tregs). Local elaboration of SLC mediated by rAAV-SLC has strong T cell mediated anti-tumor effect. The study also suggested that Tregs in the tumor microenvironment tampered the anti-tumor effect.