[bcl-2 expression in small cell lung cancer: a mechanism for apoptosis antagonism and immune evasion].

OBJECTIVE: To observe bcl-2 expression and its correlation with apoptosis antagonism and immune evasion of small cell lung cancer cell line and explore the application of bcl-2 antisense thio-oligonucleotide (bcl-2 SON) in gene therapy for lung cancer. METHODS: Western blotting was performed to detect bcl-2 expression in NCI-H69 cell line expressing Bcl-2 protein treated with bcl-2 SON. The treated NCI-H69 cells, along with the cells without bcl-2 SON treatment and NCI-H82 cells that did not express Bcl-2 protein, were respectively co-cultured with tumor-infiltrating lymphocytes (TILs) isolated from fresh tumor samples, and the apoptosis of the lung cancer cells was assessed by JAM assay. RESULTS: Western blotting revealed obvious inhibition of bcl-2 expression in NCI-H69 cells in response to bcl-2 SON treatment. JAM assay showed that the apoptosis of bcl-2 SON-treated H69 cells and NCI-H82 cells increased with the elevation of TIL ratio in the co-culture, while such changes were not observed in NCI-H69 cells without bcl-2 SON treatment. CONCLUSION: Small cell lung cancer cells expressing bcl-2 may antagonize the antitumor immune attack in the host, and bcl-2 SON may provide an effective alternative in gene therapy for small cell lung cancer.

[A dynamic study on titer of EB virus VCA/IgA and EA/IgA in nasopharygeal carcinoma patients].

OBJECTIVE: To analyze the change of EB virus VCA/IgA and EA/IgA titer during the development of nasopharyngeal carcinoma (NPC), and the role in screening for NPC. METHODS: VCA/IgA and EA/IgA were monitored in a period of 12 years by immunoenzymatic titration from the sera of 54 NPC patients after primary serological screening. RESULTS: VCA/IgA and EA/IgA titer had shown gradual increment 1 - 7 years before NPC was pathologically diagnosed. The mean titer of VCA/IgA was 1:21.04, 7 - 4 years before diagnosis. VCA/IgA titer ascended quickly within 3 years before diagnosis. The geometric mean titer (GMT) of VCA/IgA and EA/IgA were 1:76.86 and 1:6.49 when NPC was diagnosed, which descended quickly after radiotherapy and, in 4 years, approached the average titer of VCA/IgA positive population. CONCLUSION: VCA/IgA titer rises uninterruptedly 3 years before NPC is diagnosed pathologically in most patients but their EA/IgA titer rises slowly. The detection of VCA/IgA titer can be used to find early NPC, whereas EA/IgA can not. The pre-clinical phase of NPC is 3 years according to this dynamic study.

[Clinical analysis and long-term follow up study of asymptomatic nasopharyngeal carcinoma patients].

OBJECTIVE: To observe the character of Epstein-Barr(EB) virus serology, fibroscopy appearance and prognosis of asymptomatic nasopharyngeal carcinoma(NPC). METHODS: Viral capsid antigen's IgA (VCA/IgA) of EB virus and early antigen's IgA(EA/IgA) of EB virus were detected by immunoenzymatic method. The clinical examination was carried out, including indirect mirror examination and fibroscopy of the nasopharynx and multiple biopsies. All patients of NPC were followed up to the end of 1999. RESULTS: 1. The geometric mean titer of VCA/IgA and EA/IgA are 1:100.79 and 1:10.76 respectively when asymptomatic NPC was diagnosed. There were no significant difference between VCA/IgA and EA/IgA antibody titres of asymptomatic patients and symptomatic cases (P > 0.05). The survival rates in these asymptomatic cases were higher than symptomatic patients (P < 0.05). 2. There was no correlation with the VCA/IgA or EA/IgA titer and the prognosis (P > 0.05) and the cervical lymph node metastasis (P > 0.05) when NPC was diagnosed. CONCLUSION: This is helpful to detect asymptomatic NPCs by EB serological screening periodically and nasopharyngeal fibroscopy and multiple biopsies.

Assessing the risk of nasopharyngeal carcinoma on the basis of EBV antibody spectrum.

We have evaluated the performance of 3 new EBV ELISA for the diagnosis of nasopharyngeal carcinoma (NPC). The tests were specific for EBNA 1 IgA, EBNA 1 IgG and zta IgG, respectively. Their distinct antigenic specificity permits these assays to be used in concert in an approach that differentiates patients and apparently healthy subjects on the basis of their antibody spectrum. By so exploiting a distinguishing feature of NPC first described by Lloyd Olds and his group (Olds et al., Proc Nat Acad Sci 1966;56:1699-1704) [corrected] that the patients sustain high levels of a broad spectrum of serum EBV antibodies, this approach achieved a sensitivity of 92% and a specificity of 93%, surpassing the performance of each of these assays individually. The enhanced performance is especially useful in population screening. It was shown that relative risk of NPC sustained by apparently healthy subjects residing in a high incidence area for NPC in the Pearl River estuary in Southern China may vary according to EBV antibody spectrum. The risk of the cancer was markedly reduced with odds ratios of 0.009 for 59% of those who had low level of all 3 antibodies. The risk was increased as antibody spectrum broadens and the risk was the highest with an odds ratio of 138 for 0.4% of those who had high levels of all 3 antibodies. Thus, EBV antibody spectrum may serve to guide follow-up measures for early detection of the cancer and/or risk counseling according to level of the risk of the cancer sustained by the screened individuals.