[Association of antigen processing machinery and HLA class I defects with clinicopathological outcome in laryngeal squamous cell carcinoma].

Objective: To investigate the role of antigen-processing machinery (APM) component defects in HLA class I antigen down-regulation in laryngeal squamous cell carcinoma (SCC) and to assess the clinical significance of these defects.

Methods: Fifty-one formalin-fixed, paraffin-embedded SCC specimens were examined for the expressions of APM component transporter associated with antigen processing (TAP1) and low molecular weight polypeptide (LMP-7) and HLA class I antigen by immunohistochemistry.

Results: HLA class I antigens, TAP-1 and LMP-7 expressions were down-regulated in 56.

[Advances in human papillomavirus therapeutic vaccine].

Human papillomavirus (HPV) infection is very common but with limited therapies available. Although the prophylactic vaccination will be promoted worldwide soon, it can only show its benefits decades later. For individuals who already have established infections and dysplasias, it has little efficacy.

[Effects of E1A gene on the growth and chemosensitivity of transplantation tumor of nude mice].

Objective: To study the effects of E1A gene on the growth and chemosensitivity of transplantation tumor of nude mice of lymph node metastasis cell line (686LN-1) of human tongue squamous cell carcinoma.

Methods: 686LN-1, 686LN-1-vect and 686LN-1-E1A cells were transplanted into nude mice, then the time of tumor formation, growth rates and weight of tumor were observed. To study the effects of the E1A gene on bleomycin sensitivity in vivo, 686LN-1 cells were injected into nude mice.

[Expression of HPV16-E6 and E7 oncoproteins in squamous cell carcinoma tissues of esophageal cancer and non-cancer tissues].

Background & Objective: Evidences indicate that high-risk type human papillomavirus (HPV) are closely associated with the carcinogenesis, progression and transformation of several kinds of human tumors. This study was designed to determine the expression of HPV16- E6 and E7 oncoproteins in normal tissues, dysplasia tissues, and carcinoma tissues of patients with esophageal cancer and to investigate the biological significance of high-risk type HPV in the esophageal squamous cell carcinogenesis.

Methods: HPV16-E6 and E7 oncoproteins were determined using immunohistochemical staining in normal mucosa tissues (70 cases), dysplasia tissues (43 cases), and carcinoma tissues (18 cases).

[Isolation of E1A-related drug-sensitive new genes by suppression subtractive hybridization].

Background & Objective: It has been well demonstrated that E1A, as a tumor suppression gene, is capable of inhibiting the growth and metastasis of different tumors, and reversing the malignant phenotype. Particularly, the gene possesses the ability to greatly enhance the drug-sensitivity of tumor cells to several antitumor agents, and also increase the radio-sensitivity. However, the associated genes through which E1A can exert its antitumor functions still remain unknown.

[Effect of E1A gene on in vitro growth inhibition and radiochemosensitivity of lymph node metastasis cells of human head and neck squamous cell carcinoma].

Background & Objective: Adenovirus type 5 early region 1A (E1A) gene has been found to be a tumor suppression gene recently. The protein of E1A gene regulates the expression of many cellular genes positively or negatively, and possesses the activities of inducing differentiation of tumor cell, reversing of malignant phenotype, anti-carcinogenesis and anti-metastasis. Study of E1A protein on the treatment of lymph node metastasis of human head and neck squamous cell carcinoma (HNSCC) was not reported.

[Selective myelo-protection by MDR1 and MnSOD genes regulated by a specific promoter].

Objective: To study the specific protection of myeloid cells from chemotherapeutic agents and radiation.

Methods: The recombinant retroviral vectors containing MDR1 gene and MnSOD gene regulated by APN myeloid promoter were constructed and introduced into myeloblastic cell line KG1a and hepatoma cell line BEL7402. The resistance of the cells to antitumor drugs and radiation were analyzed by cell survival assay.

[MnSOD gene regulated by aminopeptidase N promoter specifically protects bone marrow from radiation].

Background & Objective: It is an effective way to induce radio-tolerant gene into hematopoietic cells in bone marrow for overcoming the suppression of radiotherapy on hematopoietic system. However, this also increases the radiation tolerance of tumor cells. This study was designed to investigate a method to specifically protect bone marrow cell from being damaged by radiation, along without increasing resistance of tumor cell to radiation.