RB Activity Alters Checkpoint Response and Chemosensitivity in Lung Cancer Lines

Michael F. Reed, William A. Zagorski, Erik S. Knudsen

Research output: Contribution to journalArticle

8 Citations (Scopus)

Abstract

Background: The retinoblastoma tumor suppressor (RB) is a key regulator of cell cycle progression and is functionally inactivated in the majority of human non-small cell lung cancers (NSCLC). The specific influence of RB on therapeutic response in NSCLC remains elusive. Materials and methods: We investigated the consequence of reintroduction of RB on checkpoint response and chemosensitivity in NSCLC cell lines. RB introduction into RB-proficient (NCI-H1299) and -deficient (H1734, H2172) NSCLC cells was achieved by adenoviral infection. RB/E2F target gene expression was determined by immunoblot analysis. Cell cycle response and viability after chemotherapeutic exposure were assessed by flow cytometry and MTT viability assay. Results: RB reconstitution in RB-deficient lines restored regulation of topoIIα, thymidylate synthase, and cyclin A. Similarly, RB overexpression in RB-proficient cells caused further regulation of some RB/E2F target genes including thymidylate synthase and topoIIα. In addition, RB overexpression resulted in restoration of the G1 arrest mechanism. Exposure of RB-proficient cells to cisplatin, etoposide, or 5-fluorouracil elicited arrest in various phases of the cell cycle while lines deficient for RB exhibited different checkpoint responses. However, introduction of RB restored ability to arrest following chemotherapeutic exposure. Chemotherapeutic challenge resulted in varying effects on cellular viability independent of RB status, yet restoration of RB activity conferred partial chemoresistance. Conclusions: These results demonstrate that RB reconstitution into RB-deficient NSCLC lines establishes regulation of certain RB/E2F target genes and restores G1 arrest mechanisms. Furthermore, introduction of RB enhances the G1 checkpoint response to chemotherapeutics and decreases chemosensitivity. Knowledge of RB-dependent chemosensitivity may ultimately contribute to individualized therapy based on molecular characterization of tumors.

Original languageEnglish (US)
Pages (from-to)364-372
Number of pages9
JournalJournal of Surgical Research
Volume142
Issue number2
DOIs
StatePublished - Oct 2007

Fingerprint

Non-Small Cell Lung Carcinoma
Lung Neoplasms
Thymidylate Synthase
Cell Cycle
Cyclin A
Retinoblastoma
Etoposide
Fluorouracil
Cisplatin
Genes
Neoplasms
Cell Survival
Flow Cytometry
Gene Expression
Cell Line
Therapeutics
Infection

Keywords

  • cell cycle
  • chemotherapy
  • lung cancer
  • retinoblastoma

ASJC Scopus subject areas

  • Surgery

Cite this

RB Activity Alters Checkpoint Response and Chemosensitivity in Lung Cancer Lines. / Reed, Michael F.; Zagorski, William A.; Knudsen, Erik S.

In: Journal of Surgical Research, Vol. 142, No. 2, 10.2007, p. 364-372.

Research output: Contribution to journalArticle

Reed, Michael F. ; Zagorski, William A. ; Knudsen, Erik S. / RB Activity Alters Checkpoint Response and Chemosensitivity in Lung Cancer Lines. In: Journal of Surgical Research. 2007 ; Vol. 142, No. 2. pp. 364-372.
@article{21b6f91fe9c147ecb22e891e84e3eb98,
title = "RB Activity Alters Checkpoint Response and Chemosensitivity in Lung Cancer Lines",
abstract = "Background: The retinoblastoma tumor suppressor (RB) is a key regulator of cell cycle progression and is functionally inactivated in the majority of human non-small cell lung cancers (NSCLC). The specific influence of RB on therapeutic response in NSCLC remains elusive. Materials and methods: We investigated the consequence of reintroduction of RB on checkpoint response and chemosensitivity in NSCLC cell lines. RB introduction into RB-proficient (NCI-H1299) and -deficient (H1734, H2172) NSCLC cells was achieved by adenoviral infection. RB/E2F target gene expression was determined by immunoblot analysis. Cell cycle response and viability after chemotherapeutic exposure were assessed by flow cytometry and MTT viability assay. Results: RB reconstitution in RB-deficient lines restored regulation of topoIIα, thymidylate synthase, and cyclin A. Similarly, RB overexpression in RB-proficient cells caused further regulation of some RB/E2F target genes including thymidylate synthase and topoIIα. In addition, RB overexpression resulted in restoration of the G1 arrest mechanism. Exposure of RB-proficient cells to cisplatin, etoposide, or 5-fluorouracil elicited arrest in various phases of the cell cycle while lines deficient for RB exhibited different checkpoint responses. However, introduction of RB restored ability to arrest following chemotherapeutic exposure. Chemotherapeutic challenge resulted in varying effects on cellular viability independent of RB status, yet restoration of RB activity conferred partial chemoresistance. Conclusions: These results demonstrate that RB reconstitution into RB-deficient NSCLC lines establishes regulation of certain RB/E2F target genes and restores G1 arrest mechanisms. Furthermore, introduction of RB enhances the G1 checkpoint response to chemotherapeutics and decreases chemosensitivity. Knowledge of RB-dependent chemosensitivity may ultimately contribute to individualized therapy based on molecular characterization of tumors.",
keywords = "cell cycle, chemotherapy, lung cancer, retinoblastoma",
author = "Reed, {Michael F.} and Zagorski, {William A.} and Knudsen, {Erik S.}",
year = "2007",
month = "10",
doi = "10.1016/j.jss.2007.03.038",
language = "English (US)",
volume = "142",
pages = "364--372",
journal = "Journal of Surgical Research",
issn = "0022-4804",
publisher = "Academic Press Inc.",
number = "2",

}

TY - JOUR

T1 - RB Activity Alters Checkpoint Response and Chemosensitivity in Lung Cancer Lines

AU - Reed, Michael F.

AU - Zagorski, William A.

AU - Knudsen, Erik S.

PY - 2007/10

Y1 - 2007/10

N2 - Background: The retinoblastoma tumor suppressor (RB) is a key regulator of cell cycle progression and is functionally inactivated in the majority of human non-small cell lung cancers (NSCLC). The specific influence of RB on therapeutic response in NSCLC remains elusive. Materials and methods: We investigated the consequence of reintroduction of RB on checkpoint response and chemosensitivity in NSCLC cell lines. RB introduction into RB-proficient (NCI-H1299) and -deficient (H1734, H2172) NSCLC cells was achieved by adenoviral infection. RB/E2F target gene expression was determined by immunoblot analysis. Cell cycle response and viability after chemotherapeutic exposure were assessed by flow cytometry and MTT viability assay. Results: RB reconstitution in RB-deficient lines restored regulation of topoIIα, thymidylate synthase, and cyclin A. Similarly, RB overexpression in RB-proficient cells caused further regulation of some RB/E2F target genes including thymidylate synthase and topoIIα. In addition, RB overexpression resulted in restoration of the G1 arrest mechanism. Exposure of RB-proficient cells to cisplatin, etoposide, or 5-fluorouracil elicited arrest in various phases of the cell cycle while lines deficient for RB exhibited different checkpoint responses. However, introduction of RB restored ability to arrest following chemotherapeutic exposure. Chemotherapeutic challenge resulted in varying effects on cellular viability independent of RB status, yet restoration of RB activity conferred partial chemoresistance. Conclusions: These results demonstrate that RB reconstitution into RB-deficient NSCLC lines establishes regulation of certain RB/E2F target genes and restores G1 arrest mechanisms. Furthermore, introduction of RB enhances the G1 checkpoint response to chemotherapeutics and decreases chemosensitivity. Knowledge of RB-dependent chemosensitivity may ultimately contribute to individualized therapy based on molecular characterization of tumors.

AB - Background: The retinoblastoma tumor suppressor (RB) is a key regulator of cell cycle progression and is functionally inactivated in the majority of human non-small cell lung cancers (NSCLC). The specific influence of RB on therapeutic response in NSCLC remains elusive. Materials and methods: We investigated the consequence of reintroduction of RB on checkpoint response and chemosensitivity in NSCLC cell lines. RB introduction into RB-proficient (NCI-H1299) and -deficient (H1734, H2172) NSCLC cells was achieved by adenoviral infection. RB/E2F target gene expression was determined by immunoblot analysis. Cell cycle response and viability after chemotherapeutic exposure were assessed by flow cytometry and MTT viability assay. Results: RB reconstitution in RB-deficient lines restored regulation of topoIIα, thymidylate synthase, and cyclin A. Similarly, RB overexpression in RB-proficient cells caused further regulation of some RB/E2F target genes including thymidylate synthase and topoIIα. In addition, RB overexpression resulted in restoration of the G1 arrest mechanism. Exposure of RB-proficient cells to cisplatin, etoposide, or 5-fluorouracil elicited arrest in various phases of the cell cycle while lines deficient for RB exhibited different checkpoint responses. However, introduction of RB restored ability to arrest following chemotherapeutic exposure. Chemotherapeutic challenge resulted in varying effects on cellular viability independent of RB status, yet restoration of RB activity conferred partial chemoresistance. Conclusions: These results demonstrate that RB reconstitution into RB-deficient NSCLC lines establishes regulation of certain RB/E2F target genes and restores G1 arrest mechanisms. Furthermore, introduction of RB enhances the G1 checkpoint response to chemotherapeutics and decreases chemosensitivity. Knowledge of RB-dependent chemosensitivity may ultimately contribute to individualized therapy based on molecular characterization of tumors.

KW - cell cycle

KW - chemotherapy

KW - lung cancer

KW - retinoblastoma

UR - http://www.scopus.com/inward/record.url?scp=34548692307&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=34548692307&partnerID=8YFLogxK

U2 - 10.1016/j.jss.2007.03.038

DO - 10.1016/j.jss.2007.03.038

M3 - Article

VL - 142

SP - 364

EP - 372

JO - Journal of Surgical Research

JF - Journal of Surgical Research

SN - 0022-4804

IS - 2

ER -