BACKGROUNDE-cadherin is a subclass of the cadherin family that plays an important role in the maintenance of intercellular junctions in normal epithelium.Decreased expression of E-cadherin might be closely related to invasiveness and dedifferentiation in human cancers.There is increasing evidence that modulation of the E-cadherin-catenin cell-cell adhesion complex is an important step in the initiation and progression of human cancers.The aim of this study is to investigate the relationship between the level of E-cadherin mRNA expression and pathological grades and clinical stages of non-small cell lung cancer(NSCLC).

METHODSRT-PCR was used to measure the level of E-cadherin mRNA expression in 53 specimens of NSCLC,46 of para-cancer lung tissues,5 of benign nodal lung diseases,and the stages of disease was determined according to the results of surgery,pathology and imaging diagnoses.Then analyses were carried out between the level of E-cadherin mRNA expression and the clinical variables.

RESULTS45.3%(24/53) and 45.7%(21/46) specimens of NSCLC and para-cancer lung tissue were positive for E-cadherin mRNA expression respectively(P > 0.05);NSCLC with low differentiation,advanced stages and nodal metastases showed a magnificantly lower expression of E-cadherin mRNA(P < 0.05).The median survival time for E-cadherin mRNA positive and negative patients were 15.5 months and 46 months,respectively,but the expression of E-cadherin mRNA did not correlate with patient's survival(P > 0.05).

CONCLUSIONSE-cadherin expression is related to the differentiation,lymph node metastasis and pathological staging of NSCLC,but probably does not effectively affect its prognosis.

Objective:To investigate the efficacy of a SARS-CoV-2 recombinant protein vaccine as a booster dose.Methods:A new immunogen, namely RBD-sc-trimer, was designed by tandem repeating of single receptor binding domain (RBD) of SARS-CoV-2 spike (S) protein to mimic the trimeric form of RBD presented by the virus. The RBD-sc-trimer protein was expressed as a His-tagged fusion protein using a baculovirus expression system and purified by nickel affinity column. The purified protein was identified by Western blot. Its in vitro binding activity to human angiotensin converting enzyme 2 (hACE2) was analyzed by ELISA. The immunogenicity of RBD-sc-trimer as well as RBD proteins of other forms including RBD dimer (RBD-Fc), RBD monomer (RBD) and S protein trimer (S trimer) as a booster dose was evaluated in BALB/c mice. Results:In terms of both binding and neutralizing antibodies against SARS-CoV-2, RBD-sc-trimer showed an immunogenicity that was superior to that of RBD-Fc and RBD and close to the level of S trimer. The antibody response induced by RBD-sc-trimer was characterized as Th1-biased. Moreover, it displayed a stronger cross-neutralization activity against SARS-CoV-2 Beta, Delta and Omicron variants. The titer of neutralizing antibody against Omicron induced by RBD-sc-trimer only decreased by 9.1 folds relative to the prototype strain, while the antibody response induced by RBD-Fc and S trimer decreased by 68.4 and 70.8 folds, respectively.Conclusions:The recombinant protein, RBD-sc-trimer, which was capable of eliciting stronger humoral response in mice as a booster dose and showed the superiority in raising cross-reactive antibodies against SARS-CoV-2 variants over non-trimeric RBD forms, should be considered as an optimal immunogen for the development of more effective SARS-CoV-2 vaccines.