Yuhuan Zhao

Tumor vaccines for cancer prevention and treatment have attracted tremendous interests in the area of cancer immunotherapy in recent years. In this work, we present a strategy to construct cancer vaccines by encapsulating immune-adjuvant nanoparticles with cancer cell membranes modified by mannose. Poly(d,l-lactide- co-glycolide) nanoparticles are first loaded with toll-like receptor 7 agonist, imiquimod (R837). Those adjuvant nanoparticles (NP-R) are then coated with cancer cell membranes (NP-R@M), whose surface proteins could act as tumor-specific antigens. With further modification with mannose moiety (NP-R@M-M), the obtained nanovaccine shows enhanced uptake by antigen presenting cells such as dendritic cells, which would then be stimulated to the maturation status to trigger antitumor immune responses. With great efficacy to delay tumor development as a prevention vaccine, vaccination with such NP-R@M-M in combination with checkpoint-blockade therapy further demonstrates outstanding therapeutic efficacy to treat established tumors. Therefore, our work presents an innovative way to fabricate cancer nanovaccines, which in principle may be applied for a wide range of tumor types.

Background: We aimed to characterize the relationships of lymphocyte activation gene-3 (LAG-3) expression, cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4) expression, and CD8+ tumor-infiltrating lymphocyte (TIL) density, and to investigate the joint prognostic impact of these three markers in patients with surgically resected esophageal squamous cell carcinoma (ESCC). Methods: Expression of LAG-3, CTLA-4 and the density of CD8+ TILs were evaluated by immunohistochemistry in resected ESCC. The associations between LAG-3 expression and clinicopathologic characteristics, as well as patient prognoses, were analyzed. Results: A total of 183 patients were included. LAG-3 expression was observed in 69 (37.7%) patients. Positive LAG-3 expression was significantly associated with CTLA-4 expression (P=0.004). LAG-3 positivity, CTLA-4 positivity, and low CD8+ TIL densities were significantly associated with worsening recurrence-free survival (RFS) [LAG-3: hazard ratio (HR), 1.72; 95% confidence interval (CI), 1.10–2.89; P=0.019; CTLA-4: HR, 1.69; 95% CI, 1.04–2.73; P=0.033; CD8+: HR, 0.60; 95% CI, 0.38–0.94; P=0.025] and overall survival (OS) (LAG-3: HR, 2.09; 95% CI, 1.24–3.53; P=0.006; CTLA-4: HR, 1.47; 95% CI, 0.86–2.53; P=0.161; CD8+: HR, 0.56; 95% CI, 0.33–0.95; P=0.032). Subgroup analysis revealed that the LAG-3 CTLA-4 CD8+ group had the best RFS (P<0.001) and OS (P<0.001). Conclusions: LAG-3 expression was correlated with CTLA-4 expression on TILs. Positive LAG-3 expression was associated with poor prognoses in ESCC. A combination of LAG-3, CTLA-4 expression and CD8+ TILs density could further stratify patients into different subgroups with distinct prognoses.

There is increasing evidence that inflammation-based biomarkers are associated with tumor microenvironment which plays important roles in cancer progression. A high lymphocyte-to-monocyte ratio (LMR), has been suggested to indicate favorable prognoses in various epithelial cancers. We performed a meta-analysis to quantify the prognostic value of LMR in advanced-stage epithelial cancers undergoing various treatment. We searched PubMed, EMBASE, Web of science and Cochrane Library up to July 2018 for relevant studies. We included studies assessing the prognostic impact of pretreatment LMR on clinical outcomes in patients with advanced-stage epithelial cancers. The primary outcome was overall survival (OS) and the secondary outcome was progression free survival (PFS). The summary hazard ratio (HR) and 95% confidence interval (CI) were calculated. A total of 8984 patients from 35 studies were included. A high pretreatment LMR was associated with favorable OS (HR = 0.578, 95% CI 0.522–0.641, P < 0.001) and PFS (HR = 0.598, 95% CI 0.465–0.768, P < 0.001). The effect of LMR on OS was observed among various tumor types. A higher pretreatment LMR was associated with improved OS in chemotherapy (n = 10, HR = 0.592, 95% CI 0.518–0.676, P < 0.001), surgery (n = 10, HR = 0.683, 95% CI 0.579–0.807, P < 0.001) and combined therapy (n = 11, HR = 0.507, 95% CI 0.442–0.582, P < 0.001) in the subgroup analysis by different therapeutic strategies. The cut-off value for LMR was 3.0 (range = 2.35–5.46). Subgroup analysis according to the cut-off value showed a significant prognostic value of LMR on OS and PFS in both subgroups. A high pretreatment LMR is associated with favorable clinical outcomes in advanced-stage epithelial cancers undergoing different therapeutic strategies. LMR could be used to improve clinical decision-making regarding treatment in advanced epithelial cancers.

The development of effective cancer vaccines is an important direction in the area of cancer immunotherapy. Although certain types of preventive cancer vaccines have already been used in the clinic, therapeutic cancer vaccines for treatment of already established tumors are still in high demand. In this study, we develop a new type of cancer vaccine by mixing cell-penetrating peptide (CPP) conjugated antigen as the enhanced antigen, together with CpG as the immune adjuvant. A special CPP, cytosol-localizing internalization peptide 6 (CLIP6), which has the ability to enter cells exclusively via a nonendosomal mechanism, i.e., direct translocation across the cell membrane, is conjugated with model antigen ovalbumin (OVA). Compared to naked OVA, the obtained CLIP6-OVA conjugates show greatly increased uptake by dendritic cells (DCs) and, more importantly, remarkably enhanced antigen cross-presentation, eliciting stronger cytotoxic T lymphocyte (CTL) mediated immune responses with the help of CpG. This CLIP6-OVA/CpG formulation offers effective protection for mice against challenged B16-OVA tumors, and is able to further function as a therapeutic vaccine, which, in combination with immune checkpoint blockade therapy, can significantly suppress the already-established tumors. Such a CLIP6-based cancer vaccine developing strategy shows promising potential toward clinical practice owing to its features of easy preparation, low cost, and remarkable biocompatibility.

BACKGROUND: We performed a systematic review and meta-analysis to synthesize the available evidence regarding short-term outcomes between minimally invasive esophagectomy (MIE) and open esophagectomy (OE). METHODS: Studies were identified by searching databases including PubMed, EMBASE, Web of Science and Cochrane Library up to March 2019 without language restrictions. Results of these searches were filtered according to a set of eligibility criteria and analyzed in line with PRISMA guidelines. RESULTS: There were 33 studies included with a total of 13 269 patients in our review, out of which 4948 cases were of MIE and 8321 cases were of OE. The pooled results suggested that MIE had a better outcome regarding all-cause respiratory complications (RCs) (OR = 0.56, 95% CI = 0.41-0.78, P = <0.001), in-hospital duration (SMD = -0.51; 95% CI = -0.78-0.24; P = <0.001), and blood loss (SMD = -1.44; 95% CI = -1.95-0.93; P = <0.001). OE was associated with shorter duration of operation time, while no statistically significant differences were observed regarding other outcomes. Additionally, subgroup analyses were performed for a number of different postoperative events. CONCLUSIONS: Our study indicated that MIE had more favorable outcomes than OE from the perspective of short-term outcomes. Further large-scale, multicenter randomized control trials are needed to explore the long-term survival outcomes after MIE versus OE.