Sandra Jensen

Expression of early lung cancer detection marker p31 in neoplastic and non-neoplastic respiratory epithelium

In an immunocytochemical study of sputum, two antibodies, including a mouse monoclonal antibody (703D4) to a 31 kDa protein (p31) antigen, have been previously shown to detect lung cancer earlier than routine cytomorphology or chest X-ray. To understand the basis of p31 expression, the distribution of this antigen in the respiratory epithelium of individuals known to have lung cancer was mapped. These individuals are likely to demonstrate extensive changes throughout the epithelium due to field cancerization. p31 immunoreactivity was examined in primary tumors and surrounding non-neoplastic lungs containing both histologically normal and abnormal areas obtained from 28 Stage I non-small cell lung cancer (NSCLC) patients. Distribution and intensity of p31 expression was scored in three lung compartments (bronchi, bronchioli, alveoli). While p31 was present in histologically unremarkable bronchial and bronchiolar epithelium, no expression was detected in bronchi or bronchioli containing histologic abnormalities. Furthermore, in the peripheral lung p31 staining was frequently observed in alveolar type II cells and was most commonly detected in reactive, hyperplastic type II cells. When p31 immunoreactivity was correlated with clinicopathological features, a statistically significant increase in p31 expression was found both in bronchioli and alveoli of older individuals a well as in bronchioli of patients with most extensive smoking exposure. We conclude that p31 expression occurs in both non-neoplastic and neoplastic epithelium of the human respiratory tract. The increased expression of p31 in the peripheral lung may be potentially informative as to what critical cell populations are involved in the development of invasive cancers. Moreover, this study provides a model approach for analysis of the nature of early epithelial changes leading to the development of lung cancer.

Antibody 624H12, which detects lung cancer at early stages, recognizes a sugar sequence in the glycosphingolipid difucosylneolactonorhexaosylceramide (V3FucIII3FucnLc6Cer)

Immunocytochemical staining of cells in sputum by rat monoclonal antibody 624H12 detects lung cancer 2 years prior to its detection by conventional diagnostic techniques. The antigen recognized by antibody 624H12 is a sugar sequence in the glycosphingolipid difucosylneolactonorhexaosylceramide (V3FucIII3FucnLc6Cer) whose structure is (formula see; text) Both fucosyl residues are required for high affinity binding by the antibody. The antigen was expressed in 35 of 45 specimens of cancer tissue from patients with early stage non small cell lung cancer. There was no correlation between antigen expression and patient survival.

Detection of K-ras point mutation by in situ PCR in cell suspensions: Comparison of the indirect and direct methods

In situ PCR is a new technique for the localization of low copy number sequences. We report here a method for the in situ visualization of a point mutation in K-ras codon 12 by indirect in situ PCR. Twenty-five primers were examined to select mutant-specific primers. Harvested cell lines were fixed and suspended in PCR mixture. Forty cycles of PCR in cell suspension was performed in a thermal cycler using a hot start method. Cells were cytocentrifuged onto slides, and post-fixation was performed. The specimens on the slides were then hybridized with a digoxigenin-labeled probe, followed by color reaction. Both Calu-1 (mutated: TGT) and NCI-H460 (wild type: GGT) cells had strong hybridization signals in the nuclei with general primers. But with mutant-specific primers, only Calu-1 cells had hybridization signals. No signal was observed without primers or Taq DNA polymerase. Southern blotting of the same preparation confirmed desired amplification. We also applied direct in situ PCR, but this method failed to detect the point mutation. We conclude that our indirect in situ PCR method shows the feasibility of in situ identification of single cells carrying point mutations.

Abstract 676: Tissue inhibitor of metalloproteinase-2 (TIMP2) deficiency enhances tumor burden via increasing HIF-2á expression

The tissue inhibitor of metalloproteinase family of proteins (TIMPs 1-4) function as natural MMP inhibitors, and have been shown to play a role in maintenance and remodeling of the ECM as well as other cellular processes including proliferation, apoptosis and angiogenesis. A number of studies have shown that the down-regulation or silencing of TIMP2 accelerates tumor development, however, the mechanism is not well understood. High HIF-2a levels in non-small cell lung cancer (NSCLC) correlate with decreased overall survival, while inhibition of HIFs targeted genes VEGF or VEGFR2 are associated with improved clinical outcome. Similarly, TIMP2 mRNA levels were found to be low in NSCLC compared to the corresponding non-neoplastic surrounding lung (p Citation Format: Sarvesh Kumar, Sandra M. Jensen, Ananda Chowdhury, Beiyang Wei, William G. Stetler-Stevenson. Tissue inhibitor of metalloproteinase-2 (TIMP2) deficiency enhances tumor burden via increasing HIF-2a expression. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 676.