TY - JOUR
T1 - Tumor suppressor protein SMAR1 modulates the roughness of cell surface
T2 - Combined AFM and SEM study
AU - Kaul-Ghanekar, Ruchika
AU - Singh, Sandeep
AU - Mamgain, Hitesh
AU - Jalota-Badhwar, Archana
AU - Paknikar, Kishore M.
AU - Chattopadhyay, Samit
N1 - Funding Information:
This work was carried out at Agharkar Research Institute (ARI) as well as at National Center for Cell Science (NCCS). We are thankful to Director, ARI, Dr. V. S. Rao and Director, NCCS, Dr. G. C. Mishra for allowing us to complete this work. We also thank Nano Cutting Edge Technology Ltd., Mumbai and ARI for funding this work. We thank Dr. Avinash Pradhan, M.D., Chief Pathologist, KEM Hospital, Pune, for providing human breast cancer samples.
PY - 2009/10/2
Y1 - 2009/10/2
N2 - Background: Imaging tools such as scanning electron microscope (SEM) and atomic force microscope (AFM) can be used to produce high-resolution topographic images of biomedical specimens and hence are well suited for imaging alterations in cell morphology. We have studied the correlation of SMAR1 expression with cell surface smoothness in cell lines as well as in different grades of human breast cancer and mouse tumor sections. Methods: We validated knockdown and overexpression of SMAR1 using RT-PCR as well as Western blotting in human embryonic kidney (HEK) 293, human breast cancer (MCF-7) and mouse melanoma (B16F1) cell lines. The samples were then processed for cell surface roughness studies using atomic force microscopy (AFM) and scanning electron microscopy (SEM). The same samples were used for microarray analysis as well. Tumors sections from control and SMAR1 treated mice as well as tissues sections from different grades of human breast cancer on poly L-lysine coated slides were used for AFM and SEM studies. Results: Tumor sections from mice injected with melanoma cells showed pronounced surface roughness. In contrast, tumor sections obtained from nude mice that were first injected with melanoma cells followed by repeated injections of SMAR1-P44 peptide, exhibited relatively smoother surface profile. Interestingly, human breast cancer tissue sections that showed reduced SMAR1 expression exhibited increased surface roughness compared to the adjacent normal breast tissue. Our AFM data establishes that treatment of cells with SMAR1-P44 results into increase in cytoskeletal volume that is supported by comparative gene expression data showing an increase in the expression of specific cytoskeletal proteins compared to the control cells. Altogether, these findings indicate that tumor suppressor function of SMAR1 might be exhibited through smoothening of cell surface by regulating expression of cell surface proteins. Conclusion: Tumor suppressor protein SMAR1 might be used as a phenotypic differentiation marker between cancerous and non-cancerous cells.
AB - Background: Imaging tools such as scanning electron microscope (SEM) and atomic force microscope (AFM) can be used to produce high-resolution topographic images of biomedical specimens and hence are well suited for imaging alterations in cell morphology. We have studied the correlation of SMAR1 expression with cell surface smoothness in cell lines as well as in different grades of human breast cancer and mouse tumor sections. Methods: We validated knockdown and overexpression of SMAR1 using RT-PCR as well as Western blotting in human embryonic kidney (HEK) 293, human breast cancer (MCF-7) and mouse melanoma (B16F1) cell lines. The samples were then processed for cell surface roughness studies using atomic force microscopy (AFM) and scanning electron microscopy (SEM). The same samples were used for microarray analysis as well. Tumors sections from control and SMAR1 treated mice as well as tissues sections from different grades of human breast cancer on poly L-lysine coated slides were used for AFM and SEM studies. Results: Tumor sections from mice injected with melanoma cells showed pronounced surface roughness. In contrast, tumor sections obtained from nude mice that were first injected with melanoma cells followed by repeated injections of SMAR1-P44 peptide, exhibited relatively smoother surface profile. Interestingly, human breast cancer tissue sections that showed reduced SMAR1 expression exhibited increased surface roughness compared to the adjacent normal breast tissue. Our AFM data establishes that treatment of cells with SMAR1-P44 results into increase in cytoskeletal volume that is supported by comparative gene expression data showing an increase in the expression of specific cytoskeletal proteins compared to the control cells. Altogether, these findings indicate that tumor suppressor function of SMAR1 might be exhibited through smoothening of cell surface by regulating expression of cell surface proteins. Conclusion: Tumor suppressor protein SMAR1 might be used as a phenotypic differentiation marker between cancerous and non-cancerous cells.
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U2 - 10.1186/1471-2407-9-350
DO - 10.1186/1471-2407-9-350
M3 - Article
C2 - 19799771
AN - SCOPUS:70449629035
SN - 1471-2407
VL - 9
SP - 350
JO - BMC cancer
JF - BMC cancer
M1 - 350
ER -