Non-malignant respiratory epithelial cells preferentially proliferate from resected non-small cell lung cancer specimens cultured under conditionally reprogrammed conditions

Abstract

The “conditionally reprogrammed cells” (CRC) method, using a Rho kinase inhibitor and irradiated mouse fibroblast cells has been described for the efficient growth of cells from malignant and non-malignant samples from primary tumor and non-malignant sites. Using the CRC method, four institutions independently cultured tumor tissues from 48 non-small cell lung cancers (NSCLC, mostly from primary resected tumors) and 22 non-malignant lungs. We found that epithelial cells could be cultured from tumor and non-malignant lung. However, epithelial cells cultured from tumors had features of non-malignant respiratory epithelial cells which include: 1) among 22 mutations found in the original tumors only two mutations were found in the CRC cultures with reduced frequency (31% to 13% and 92% to 15% from original tumor and CRC culture respectively); 2) copy number variation was analyzed in 9 tumor and their CRC cultures and only diploid patterns were found in CRC cultures; 3) mRNA expression profiles were similar to those of normal respiratory epithelial cells; and 4) co-culture of tumor and non-malignant lung epithelial cells resulted in mostly non-malignant cells. We conclude that CRC method is a highly selective and useful method for the growth of non-malignant respiratory epithelial cells from tumor specimens and only occasionally do such CRC cultures contain a small subpopulation of cancer cells marked by oncogenic mutations. While our findings are restricted to resected primary NSCLC, they indicated the necessity to fully characterize all CRC cultures and the need to develop culture technology that facilitates the growth of primary lung cancers.

Expansion of airway basal epithelial cells from primary human non‐small cell lung cancer tumors

“…and others 11, 12. Even after careful dissection of tissue by a pathologist to obtain normal lung and tumor samples, bronchioles containing normal airway epithelium can be found in the NSCLC tumor microenvironment (Fig.…”

“…Our results suggest that a very small number of contaminating normal airway basal cells contained within LUAD tumors are sufficient to initiate cell cultures in these conditions, corroborating the recent findings of Sette et al 13 and others. 11,12 Even after careful dissection of tissue by a pathologist to obtain normal lung and tumor samples, bronchioles containing normal airway epithelium can be found in the NSCLC tumor microenvironment ( Fig. 1e).…”

“…Despite containing less tissue, biopsies or pleural effusion samples might also be advantageous for initiating tumor cultures by virtue of their lack of contaminating normal epithelium 9 as normal epithelial cells outgrow patient-matched cancer cells in controlled 3T3 1 Y experiments. 11 Normal cells also outcompete tumor-derived cells during cancer organoid derivation. Here, it has been possible to develop tumorspecific media to select tumor organoids over normal colonic 25 and hepatic 26 epithelial organoids.…”

“…However, others have found that normal epithelial cells are preferentially expanded in these conditions 11, 12. For example, Sette et al .…”

“…[7][8][9][10] However, others have found that normal epithelial cells are preferentially expanded in these conditions. 11,12 For example, Sette et al recently showed strong selection for normal, non-tumorigenic airway epithelial cells and/ or no tumor cell expansion from 19 surgically resected NSCLC tumors of mixed histological subtypes, 4 pulmonary metastases, 2 lung cancer brain metastases and 1 patient-derived xenograft (PDX) model. 13 Here, we present cell culture outcomes for 12 lung adenocarcinoma patients enrolled in the on-going Tracking Cancer Evolution through Therapy (TRACERx) clinical study.…”