[Detection of Mycobacterium tuberculosis in lung cancer tissue by indirect in situ nested PCR].

OBJECTIVE: To localize Mycobacterium tuberculosis DNA (TB-DNA) in lung cancer tissue and to investigate the possible relationship of this bacterial infection with the development of lung cancer. METHODS: A sensitive and specific indirect in situ nested PCR (ISNPCR) was used to identify and localize TB-DNA in 15 formalin fixed paraffin-embedded lung cancer tissue specimens, which had been demonstrated to be positive for TB-DNA by conventional PCR. RESULTS: Positive granules of TB-DNA in brown color was found mainly in the cytoplasm of the alveolar epithelial cells, pulmonary macrophages, inflammatory cells and a few tumor cells within lung cancer tissues. CONCLUSION: Mycobacterium tuberculosis infection may play a role in the pathogenesis of lung cancer.

[Detection of bcl-2/IgH gene rearrangement in diffuse large B cell lymphoma by hemi-nested PCR].

OBJECTIVES: To explore a sensitive and specific method for detection of bcl-2/IgH gene rearrangement in diffuse large B cell lymphoma (DLBCL), and verify the credibility of the established method. METHODS: bcl-2/IgH hemi-nested PCR primers were designed using the professional primer design software. Fifty-two samples of pathologically diagnosed DLBCL and 10 fresh tonsil tissues were amplified using hemi-nested touch down-PCR to detect bcl-2/IgH gene rearrangement. The PCR products were cloned and sequenced. RESULTS: bcl-2/IgH gene rearrangement was detected in 6 of 52 DLBCL samples and 2 of 10 fresh tonsil tissues using one-way method. By using the hemi-nested PCR for the second round amplification, 5 of DLBCL were positive, but all of the fresh tonsil tissues were negative. The positive PCR products were sequenced and analyzed on the Internet, 3 of 8 cases obtained by one-way method were false positive, 5 positive cases amplified using hemi-nested PCR were all bcl-2/IgH gene rearrangement. PCR products of 3 false positive cases were homologous to BAC331191 and LLNLR-245D11 in human chromosome 19 and RP11-498P10 in chromosome 1. CONCLUSION: There are false positive results using common primers for detecting bcl-2/IgH gene rearrangement. The mechanism may be that highly homologous sequences to human genome exist in commonly used primers. The specificity of the diagnosis could be improved by hemi-nested PCR using the combination of primers we designed and the traditional ones.

[Detection of KIAA1173 gene expression in nasopharyngeal carcinoma tissues and cell lines on tissue microarray].

BACKGROUND & OBJECTIVE: Although the molecular etiology of nasopharyngeal carcinoma (NPC) is still unknown, studies showed that there are NPC-associated tumor suppressor genes residing in chromosome 3p21-22. KIAA1173 gene, locates at 3p22.1, was characterized as a new carcinoma-related gene, while its correlation to tumorigenesis of NPC hasn't been reported yet. This study was to detect the expression of KIAA1173 gene in NPC tissues and cell lines, and investigate its involvement in NPC. METHODS: KIAA1173 gene fragment (354 bp) was cloned, and the cDNA probe was prepared. The expression of KIAA1173 gene in 73 nasopharyngeal tissue samples (including 41 specimens of NPC, 18 atypical hyperplasia epithelia, and 14 normal nasopharyngeal mucosa epithelia) and 6 NPC cell lines (including CNE1, CNE2, HNE1, HNE2, 6-10B, and 5-8F) were examined using tissue microarray technique by in situ hybridization (ISH). RESULTS: The positive rates of KIAA1173 mRNA were 21.9% (9/41) in NPC, 83.3% (15/18) in atypical hyperplasia epithelia, 92.8% (13/14) in normal nasopharyngeal mucosa epithelia, and 0 in all NPC cell lines. Its strongly positive rate was significantly lower in NPC than in atypical hyperplasia epithelia and normal mucosa epithelia (0 vs. 38.9% and 64.3%, P < 0.001). In 38 specimens of NPC with infiltrated lymphocytes, the positive rate of KIAA1173 mRNA was significantly lower in cancer cells than in tumor infiltrating lymphocytes (23.7% vs. 44.7%, P < 0.05); the expression of KIAA1173 in cancer cells was negatively related to that in tumor infiltrating lymphocytes (kappa = -0.337, P < 0.05). CONCLUSIONS: KIAA1173 gene is strongly expressed in normal nasopharyngeal mucosa epithelia, but down-regulated in NPC. It may be associated with the tumorigenesis of NPC. Tissue microarray;

[Chromosomal imbalance in primary lung squamous cell carcinoma and their relationship with smoking].

BACKGROUND & OBJECTIVE: Chromosomal imbalance plays an important role in tumorigenesis of lung cancer, and may be influenced by different carcinogens. This study was to examine chromosomal imbalance in primary lung squamous cell carcinoma (LSCC), and their association with smoking. METHODS: Chromosomal gains and losses in 39 specimens of LSCC were identified by comparative genomic hybridization (CGH), the association between chromosomal imbalances in LSCC and smoking was analyzed. RESULTS: The most frequent chromosomal gains of LSCC were detected on chromosomal arms 3q (74.4%, 29/39), 5p (66.7%, 26/39), 1q (43.6%, 17/39), 8q (41.0%, 16/39), 12p (42.6%, 18/39), 2p (38.5%, 15/39), and 18p (33.3%, 13/39), with minimal amplified regions (MAR) at 3q26.2-29 (74.4%, 29/39), 5p14.3-15.3 (66.7%, 26/39), 1q41-44(41.0%, 16/39), 8q23 (41.0%, 16/39), 12p13 (41.0%, 16/39), and 18p11.2 (33.3%, 13/39)u high-copy-number amplification at chromosomal arms 3q, and 5p were found in 15 (38.5%), and 6 (15.4%) patients. Chromosomal losses mainly involved chromosomal arms 3p (56.4%, 22/39), 5q (53.8%, 21/39), 13q (51.3%, 20/39), 8p (46.1%, 18/39), 4p (43.6%, 17/39), 4q (43.6%, 17/39), 1p (41.0%, 16/39), 2q (38.5%, 15/39), 9q (35.9%, 14/39), 13p (35.9%, 14/39), 16p (35.9%, 14/39) ,6p (33.3%, 13/39), and 6q (30.7%, 12/39), with minimal deleted regions (MDR) at 3p14.2-21.2 (51.3%, 20/39), 5q15-22 (51.3%, 20/39), 13q14.2-21.2 (48.7%, 19/39), 8p21.1-22 (43.6%, 17/39), 2q32 (35.9%, 14/39), and 16p12-13.1 (33.3%, 13/39). Amplification rates of chromosomal arms 3q, and 8q in smoking LSCC patients were significantly higher than those in non-smoking LSCC patients (P=0.002,P=0.031). While high incidences of gains at chromosomal arms 5p and 12p, and of losses at chromosomal arms 3p, 4q, and 5q were the common feature of chromosomal changes of smoking and non-smoking LSCC patients. CONCLUSION: 3q, 5p, 1q, 8q, 12p, 2p, 18p gains and 3p, 5q, 13q, 8p, 4p, 4q, 1p, 2q, 9q, 13p,16p, 6p, 6q loses might be involved in tumorigenesis and/or progression of LSCC, smoking-induced lung cancer may be associated with 3q, 8q gains.