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Phosphatidylinositol 3-kinase mediates bronchioalveolar stem cell expansion in mouse models of oncogenic K-ras-induced lung cancer.

Yang Y, Iwanaga K, Raso MG, Wislez M, Hanna AE, Wieder ED, Molldrem JJ, Wistuba II, Powis G, Demayo FJ, Kim CF, Kurie JM - PLoS ONE (2008)

Bottom Line: The signals activated by oncogenic K-ras that mediate BASC expansion have not been fully defined.Oncogenic K-ras-induced BASC accumulation and tumor growth were blocked by treatment with a small molecule PI3K inhibitor and enhanced by inactivation of phosphatase and tensin homologue deleted from chromosome 10, a negative regulator of PI3K.We conclude that PI3K is a critical regulator of BASC expansion, supporting treatment strategies to target PI3K in NSCLC patients.

View Article: PubMed Central - PubMed

Affiliation: Department of Thoracic/Head and Neck Medical Oncology, University of Texas M. D. Anderson Cancer Center, Houston, Texas, United States of America.

ABSTRACT

Background: Non-small cell lung cancer (NSCLC) is the most common cause of cancer-related death in Western countries. Developing more effective NSCLC therapeutics will require the elucidation of the genetic and biochemical bases for this disease. Bronchioalveolar stem cells (BASCs) are a putative cancer stem cell population in mouse models of oncogenic K-ras-induced lung adenocarcinoma, an histologic subtype of NSCLC. The signals activated by oncogenic K-ras that mediate BASC expansion have not been fully defined.

Methodology/principal findings: We used genetic and pharmacologic approaches to modulate the activity of phosphatidylinositol 3-kinase (PI3K), a key mediator of oncogenic K-ras, in two genetic mouse models of lung adenocarcinoma. Oncogenic K-ras-induced BASC accumulation and tumor growth were blocked by treatment with a small molecule PI3K inhibitor and enhanced by inactivation of phosphatase and tensin homologue deleted from chromosome 10, a negative regulator of PI3K.

Conclusions/significance: We conclude that PI3K is a critical regulator of BASC expansion, supporting treatment strategies to target PI3K in NSCLC patients.

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Related in: MedlinePlus

PX-866 inhibits BASC expansion in vitro.(A) Sorted cells co-express SPC and CCSP. KrasLA1 whole lung tissues were dissociated and sorted to isolate Sca-1pos CD45neg CD31neg CD34pos cells (P4 and P5 in left and middle panels, respectively), which were subjected to immunofluorescent staining (x40 magnification, right panel). Calibration bar in far right panel represents 10 μm. (B) BASCs form colonies when plated on feeder cultures. Photograph of colony (x10 magnification) formed upon initial plating (P1) and passage 2 (P2). Calibration bar in panel on right represents 50 μm. (C) BASCs differentiate when plated in matrigel. Cells were stained after 7 d in matrigel (x10 magnification) and the numbers of cells with features of alveolar type II cells (CCSPneg SPCpos), clara cells (CCSPpos SPCneg), or BASCs (CCSPpos SPCpos) were counted and expressed as the percentages of the total 158 counted cells in a pie chart. Examples of cells with features of ATII cells (ATII) and clara cells (CC) are indicated. Calibration bar in far right panel represents 50 μm. (D) PX-866 inhibits BASC colony formation. Photographs (x10 magnification) and quantification of colonies per well (5 wells per condition) formed after 6 d in the presence or absence of PX-866. Calibration bar in panel on right represents 50 μm.
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pone-0002220-g005: PX-866 inhibits BASC expansion in vitro.(A) Sorted cells co-express SPC and CCSP. KrasLA1 whole lung tissues were dissociated and sorted to isolate Sca-1pos CD45neg CD31neg CD34pos cells (P4 and P5 in left and middle panels, respectively), which were subjected to immunofluorescent staining (x40 magnification, right panel). Calibration bar in far right panel represents 10 μm. (B) BASCs form colonies when plated on feeder cultures. Photograph of colony (x10 magnification) formed upon initial plating (P1) and passage 2 (P2). Calibration bar in panel on right represents 50 μm. (C) BASCs differentiate when plated in matrigel. Cells were stained after 7 d in matrigel (x10 magnification) and the numbers of cells with features of alveolar type II cells (CCSPneg SPCpos), clara cells (CCSPpos SPCneg), or BASCs (CCSPpos SPCpos) were counted and expressed as the percentages of the total 158 counted cells in a pie chart. Examples of cells with features of ATII cells (ATII) and clara cells (CC) are indicated. Calibration bar in far right panel represents 50 μm. (D) PX-866 inhibits BASC colony formation. Photographs (x10 magnification) and quantification of colonies per well (5 wells per condition) formed after 6 d in the presence or absence of PX-866. Calibration bar in panel on right represents 50 μm.

Mentions: To determine whether PX-866 had direct effects on KrasLA1–derived BASCs, we used primary BASC cultures, which were isolated from the lungs of KrasLA1 mice by sorting for cells that were Sca-1pos, CD34pos, CD45neg, and CD31neg. These sorted cells co-expressed CCSP and SPC (Figure 5A), formed colonies when plated on feeder cultures (Figure 5B), and exhibited multi-potential differentiation capacity when plated in matrigel (Figure 5C), which are hallmarks of BASCs [8]. PX-866 treatment led to a prominent decrease in BASC colony forming activity (Figure 5D), indicating that PX-866 had a direct effect on BASCs.


Phosphatidylinositol 3-kinase mediates bronchioalveolar stem cell expansion in mouse models of oncogenic K-ras-induced lung cancer.

Yang Y, Iwanaga K, Raso MG, Wislez M, Hanna AE, Wieder ED, Molldrem JJ, Wistuba II, Powis G, Demayo FJ, Kim CF, Kurie JM - PLoS ONE (2008)

PX-866 inhibits BASC expansion in vitro.(A) Sorted cells co-express SPC and CCSP. KrasLA1 whole lung tissues were dissociated and sorted to isolate Sca-1pos CD45neg CD31neg CD34pos cells (P4 and P5 in left and middle panels, respectively), which were subjected to immunofluorescent staining (x40 magnification, right panel). Calibration bar in far right panel represents 10 μm. (B) BASCs form colonies when plated on feeder cultures. Photograph of colony (x10 magnification) formed upon initial plating (P1) and passage 2 (P2). Calibration bar in panel on right represents 50 μm. (C) BASCs differentiate when plated in matrigel. Cells were stained after 7 d in matrigel (x10 magnification) and the numbers of cells with features of alveolar type II cells (CCSPneg SPCpos), clara cells (CCSPpos SPCneg), or BASCs (CCSPpos SPCpos) were counted and expressed as the percentages of the total 158 counted cells in a pie chart. Examples of cells with features of ATII cells (ATII) and clara cells (CC) are indicated. Calibration bar in far right panel represents 50 μm. (D) PX-866 inhibits BASC colony formation. Photographs (x10 magnification) and quantification of colonies per well (5 wells per condition) formed after 6 d in the presence or absence of PX-866. Calibration bar in panel on right represents 50 μm.
© Copyright Policy
Related In: Results  -  Collection

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pone-0002220-g005: PX-866 inhibits BASC expansion in vitro.(A) Sorted cells co-express SPC and CCSP. KrasLA1 whole lung tissues were dissociated and sorted to isolate Sca-1pos CD45neg CD31neg CD34pos cells (P4 and P5 in left and middle panels, respectively), which were subjected to immunofluorescent staining (x40 magnification, right panel). Calibration bar in far right panel represents 10 μm. (B) BASCs form colonies when plated on feeder cultures. Photograph of colony (x10 magnification) formed upon initial plating (P1) and passage 2 (P2). Calibration bar in panel on right represents 50 μm. (C) BASCs differentiate when plated in matrigel. Cells were stained after 7 d in matrigel (x10 magnification) and the numbers of cells with features of alveolar type II cells (CCSPneg SPCpos), clara cells (CCSPpos SPCneg), or BASCs (CCSPpos SPCpos) were counted and expressed as the percentages of the total 158 counted cells in a pie chart. Examples of cells with features of ATII cells (ATII) and clara cells (CC) are indicated. Calibration bar in far right panel represents 50 μm. (D) PX-866 inhibits BASC colony formation. Photographs (x10 magnification) and quantification of colonies per well (5 wells per condition) formed after 6 d in the presence or absence of PX-866. Calibration bar in panel on right represents 50 μm.
Mentions: To determine whether PX-866 had direct effects on KrasLA1–derived BASCs, we used primary BASC cultures, which were isolated from the lungs of KrasLA1 mice by sorting for cells that were Sca-1pos, CD34pos, CD45neg, and CD31neg. These sorted cells co-expressed CCSP and SPC (Figure 5A), formed colonies when plated on feeder cultures (Figure 5B), and exhibited multi-potential differentiation capacity when plated in matrigel (Figure 5C), which are hallmarks of BASCs [8]. PX-866 treatment led to a prominent decrease in BASC colony forming activity (Figure 5D), indicating that PX-866 had a direct effect on BASCs.

Bottom Line: The signals activated by oncogenic K-ras that mediate BASC expansion have not been fully defined.Oncogenic K-ras-induced BASC accumulation and tumor growth were blocked by treatment with a small molecule PI3K inhibitor and enhanced by inactivation of phosphatase and tensin homologue deleted from chromosome 10, a negative regulator of PI3K.We conclude that PI3K is a critical regulator of BASC expansion, supporting treatment strategies to target PI3K in NSCLC patients.

View Article: PubMed Central - PubMed

Affiliation: Department of Thoracic/Head and Neck Medical Oncology, University of Texas M. D. Anderson Cancer Center, Houston, Texas, United States of America.

ABSTRACT

Background: Non-small cell lung cancer (NSCLC) is the most common cause of cancer-related death in Western countries. Developing more effective NSCLC therapeutics will require the elucidation of the genetic and biochemical bases for this disease. Bronchioalveolar stem cells (BASCs) are a putative cancer stem cell population in mouse models of oncogenic K-ras-induced lung adenocarcinoma, an histologic subtype of NSCLC. The signals activated by oncogenic K-ras that mediate BASC expansion have not been fully defined.

Methodology/principal findings: We used genetic and pharmacologic approaches to modulate the activity of phosphatidylinositol 3-kinase (PI3K), a key mediator of oncogenic K-ras, in two genetic mouse models of lung adenocarcinoma. Oncogenic K-ras-induced BASC accumulation and tumor growth were blocked by treatment with a small molecule PI3K inhibitor and enhanced by inactivation of phosphatase and tensin homologue deleted from chromosome 10, a negative regulator of PI3K.

Conclusions/significance: We conclude that PI3K is a critical regulator of BASC expansion, supporting treatment strategies to target PI3K in NSCLC patients.

Show MeSH
Related in: MedlinePlus