'Clinical Protocol Modification of Oncogene and Tunor Suppressor 
Gene Expression in Non-Small Cell Lung Cancer (NSCLC)" 
OBJECTIVES 
The objective of this protocol is to evaluate the toxicity and possible therapeutic efficacy of the 
intralesional administration of retroviral constructs containing antisense (AS) K- ras (for tumors with 
mutated K- ras ) and wildtype p53 (wtp^) (for tumors with mutated or deleted £^) into residual 
endobronchial NSCLC which obstructs a bronchus and which is refractory to conventional therapy. 
BACKGROUND AND RATIONALE 
2.1 Molecular events in NSCLC 
Lung cancer remains the leading cause of cancer deaths in the United States where it kills more 
than 140,000 people annually. Recently, age-adjusted mortality from lung cancer has surpassed 
that from breast cancer in women. Although implementation of smoking-reduction programs has 
decreased the prevalence of smoking, lung cancer mortality rates will remain high well into the 
21st century'. Unfortunately, all current treatment modalities, including radiation therapy, 
surgery, and chemotherapy, have limited effectiveness. The rational development of new therapies 
for lung cancer will depend on an understanding of the biology of lung cancer at the molecular 
level. Research in our laboratory has identified critical molecular events leading to NSCLC 
development and progression. The goal of this research is to directly modify the cancer cell to 
eliminate the expression of gene products which are responsible for the maintenance or 
progression of the malignant phenotype or to restore in normal form deleted or mutated gene 
products that suppress the characteristics of the malignant phenotype. 
The purpose of this protocol is to investigate molecular mechanisms that may influence the growth 
and progression of human lung cancer; our goal is development of therapeutic agents specifically 
targeted at the molecular level. The most common lung cancer histologies (80%) are grouped under 
the term non-smal 1 -cel 1 lung cancer (NSCLC) and include squamous, adenocarcinoma, and large-cell 
undifferentiated. Many of the current data on the molecular biology of lung cancer come from the 
study of the more unconmon small-cell lung cancer (SCLC). SCLC can be distinguished from NSCLC by 
the neuroendocrine features of the cells; SCLC is very responsive to chemotherapy but recurs 
rapidly after treatment. NSCLC also may serve as a model for other carcinogen-induced 
malignancies. The approaches and observations developed in this study may be applicable to other 
types of epithelial cancers. 
Abundant evidence has accumulated that the process of malignant transformation is mediated by a 
genetic paradigm’. The major lesions detected in cancer cells occur in dominant oncogenes and 
tumor suppressor genes. Dominant oncogenes have alterations in a class of genes called proto- 
oncogenes, which participate in critical normal cell functions, including signal transduction and 
transcription. Primary modifications in the dominant oncogenes that confer the ability to 
transform include point mutations, translocations, rearrangements, and amplification. Tumor 
suppressor genes appear to require homozygous loss of function, by mutation, deletion, or a 
combination of these for transformation to occur. Some tumor suppressor genes appear to play a 
role in the governance of proliferation by regulation of transcription. It is possible that 
modification of the expression of dominant and tumor suppressor oncogenes may influence certain 
characteristics of cells that contribute to the malignant phenotype. 
Despite increasing knowledge of the mechanisms Involved in oncogene-mediated transformation, 
little progress has occurred in developing therapeutic strategies that specifically target 
oncogenes and their products. Initially, research in this area was focused on dominant oncogenes, 
as these were the first to be characterized. DNA-mediated gene transfer studies showed 
acquisition of the malignant phenotype by normal cells following the transfer of DNA from 
malignant human tumors. Activated oncogenes of the r^ family were identified by this technique 
with transfection of human DNA into mouse NIH 3T3 cells. 
Dncogene Mutations in Lung Cancer 
Activation of the K- ras oncogene occurs in human NSCLC*'*. Recent studies using the polymerase 
chain reaction (PCR) and specific oligonucleotide hybridization show that a third of NSCLC 
patients have r^ family mutations*'*. However, Reynolds and coworkers, using a sensitive NIH 3T3 
cotransfection-nude mouse tumorigenicity assay, found that 12 of 14 (86%) lung tumor DNAs from 
smokers contained activated proto-oncogenes related to the ras family'. K- ras mutations occur 
primarily in adenocarcinomas, and the K- ras proto-oncogene has a point mutation in 30% to 40% of 
adenocarcinomas of the lung*'*. Thus, a minimum of 32,000 patients per year are expected to 
develop ras- mutatlon-positive lung cancer. K- ras mutations are associated with a histor” 
tobacco consumption and may contribute to tumor progression. 
The 2 ^ gene is the most frequently mutated gene yet Identified in human cancers. It is mutated 
in over 50% of human NSCLC*. The p53 gene encodes a 375-amino-acid phosphoproteln that can form 
complexes with host proteins such as large-T antigen and ElB*. Mlssense mutations are common for 
Recombinant DNA Research, Volume 19 
