In Vitro Model Systems to Investigate Drug Resistance Mechanisms in Pancreatic Cancer Cells
Affiliation(s)
1 Arizona College of Osteopathic Medicine, Midwestern University, Glendale, Arizona. 2 Department of Biochemistry, Midwestern University, Glendale, Arizona.
1 Arizona College of Osteopathic Medicine, Midwestern University, Glendale, Arizona. 2 Department of Biochemistry, Midwestern University, Glendale, Arizona.
ABSTRACT
With a 5-year survival rate of less than 6%, the diagnosis of pancreatic cancer is devastating news for any patient. Gemcitabine, the most commonly used chemotherapy drug, only improves survival by approximately 1.5 months. A major obstacle to the treatment of pancreatic cancer with gemcitabine is the development of drug resistance. To better understand the precise mechanisms by which patient tumor cells gain resistance to gemcitabine, a cell culture model system that more accurately reflects the development of drug resistance in vivo is required. In this study, cultured pancreatic adenocarcinoma BxPC-3 cells were subjected to two different treatment regimens. The first method—termed pulse method—involves periodically treating separate cultures of BxPC-3 cells with constant predetermined doses of gemcitabine. The second treatment regimen—termed incremental method—consists of treating BxPC-3 cells with increasing doses of gemcitabine from 10 to 100 nM. While all treated cells showed enhanced resistance to gemcitabine, low-dose pulse treatments were sufficient to produce highly drug-resistant cells as evidenced by higher IC50 measurements. Pulse treatments also resulted in slower growth rates and increased doubling time of the drug-resistant cells. Morphological changes indicate cellular abnormalities linked to likely epithelial-to-mesenchymal transition and drug resistance. Our preliminary results indicate that the pulse method may better simulate resistance observed in patients undergoing chemotherapy and may serve as a superior model to investigate drug-resistance. This model can also help with identification of appropriate markers that determine the presence of drug-resistant cells and help clinicians adjust treatment strategies to improve outcomes for patients suffering from pancreatic cancer.
With a 5-year survival rate of less than 6%, the diagnosis of pancreatic cancer is devastating news for any patient. Gemcitabine, the most commonly used chemotherapy drug, only improves survival by approximately 1.5 months. A major obstacle to the treatment of pancreatic cancer with gemcitabine is the development of drug resistance. To better understand the precise mechanisms by which patient tumor cells gain resistance to gemcitabine, a cell culture model system that more accurately reflects the development of drug resistance in vivo is required. In this study, cultured pancreatic adenocarcinoma BxPC-3 cells were subjected to two different treatment regimens. The first method—termed pulse method—involves periodically treating separate cultures of BxPC-3 cells with constant predetermined doses of gemcitabine. The second treatment regimen—termed incremental method—consists of treating BxPC-3 cells with increasing doses of gemcitabine from 10 to 100 nM. While all treated cells showed enhanced resistance to gemcitabine, low-dose pulse treatments were sufficient to produce highly drug-resistant cells as evidenced by higher IC50 measurements. Pulse treatments also resulted in slower growth rates and increased doubling time of the drug-resistant cells. Morphological changes indicate cellular abnormalities linked to likely epithelial-to-mesenchymal transition and drug resistance. Our preliminary results indicate that the pulse method may better simulate resistance observed in patients undergoing chemotherapy and may serve as a superior model to investigate drug-resistance. This model can also help with identification of appropriate markers that determine the presence of drug-resistant cells and help clinicians adjust treatment strategies to improve outcomes for patients suffering from pancreatic cancer.
Cite this paper
Romney, E. and Nagaraj, V. (2015) In Vitro Model Systems to Investigate Drug Resistance Mechanisms in Pancreatic Cancer Cells. Advances in Biological Chemistry, 5, 286-292. doi: 10.4236/abc.2015.57026.
Romney, E. and Nagaraj, V. (2015) In Vitro Model Systems to Investigate Drug Resistance Mechanisms in Pancreatic Cancer Cells. Advances in Biological Chemistry, 5, 286-292. doi: 10.4236/abc.2015.57026.
References
[1] Siegel, R.L., Miller, K.D. and Jemal, A. (2015) Cancer Statistics, 2015. CA: A Cancer Journal for Clinicians, 65, 5-29.
http://dx.doi.org/10.3322/caac.21254 [2] Siegel, R., Naishadham, D. and Jemal, A. (2013) Cancer Statistics, 2013. CA: A Cancer Journal for Clinicians, 63, 11- 30.
http://dx.doi.org/10.3322/caac.21166 [3] Jemal, A., Bray, F., Center, M.M., Ferlay, J., Ward, E. and Forman, D. (2011) Global Cancer Statistics. CA: A Cancer Journal for Clinicians, 61, 69-90.
http://dx.doi.org/10.3322/caac.20107 [4] Paulson, A.S., Tran Cao, H.S., Tempero, M.A. and Lowy, A.M. (2013) Therapeutic Advances in Pancreatic Cancer. Gastroenterology, 144, 1316-1326.
http://dx.doi.org/10.1053/j.gastro.2013.01.078 [5] Michl, P. and Gress, T.M. (2013) Current Concepts and Novel Targets in Advanced Pancreatic Cancer. Gut, 62, 317-326.
http://dx.doi.org/10.1136/gutjnl-2012-303588 [6] Burris 3rd, H.A., Moore, M.J., Andersen, J., et al. (1997) Improvements in Survival and Clinical Benefit with Gemcitabine as First-Line Therapy for Patients with Advanced Pancreas Cancer: A Randomized Trial. Journal of Clinical Oncology: Official Journal of the American Society of Clinical Oncology, 15, 2403-2413. [7] Kothari, N., Saif, M.W. and Kim, R. (2013) First-Line Treatment for Advanced Pancreatic Cancer. JOP: Journal of the Pancreas, 14, 129-132. [8] Long, J., Zhang, Y., Yu, X., et al. (2011) Overcoming Drug Resistance in Pancreatic Cancer. Expert Opinion on Therapeutic Targets, 15, 817-828.
http://dx.doi.org/10.1517/14728222.2011.566216 [9] Arumugam, T., Ramachandran, V., Fournier, K.F., et al. (2009) Epithelial to Mesenchymal Transition Contributes to Drug Resistance in Pancreatic Cancer. Cancer Research, 69, 5820-5828.
http://dx.doi.org/10.1158/0008-5472.CAN-08-2819 [10] Wu, Q., Miele, L., Sarkar, F.H. and Wang, Z. (2012) The Role of EMT in Pancreatic Cancer Progression. Pancreatic Disorders & Therapy, 2.
http://dx.doi.org/10.4172/2165-7092.1000e121 [11] Sarkar, F.H., Li, Y., Wang, Z. and Kong, D. (2009) Pancreatic Cancer Stem Cells and EMT in Drug Resistance and Metastasis. Minerva Chirurgica, 64, 489-500. [12] Hermann, P.C., Huber, S.L., Herrler, T., et al. (2007) Distinct Populations of Cancer Stem Cells Determine Tumor Growth and Metastatic Activity in Human Pancreatic Cancer. Cell Stem Cell, 1, 313-323.
http://dx.doi.org/10.1016/j.stem.2007.06.002 [13] Hage, C., Rausch, V., Giese, N., et al. (2013) The Novel C-Met Inhibitor Cabozantinib Overcomes Gemcitabine Resistance and Stem Cell Signaling in Pancreatic Cancer. Cell Death & Disease, 4, e627.
http://dx.doi.org/10.1038/cddis.2013.158 [14] Vaz, A.P., Ponnusamy, M.P., Rachagani, S., Dey, P., Ganti, A.K. and Batra, S.K. (2014) Novel Role of Pancreatic Differentiation 2 in Facilitating Self-Renewal and Drug Resistance of Pancreatic Cancer Stem Cells. British Journal of Cancer, 111, 486-496. [15] Hong, S.P., Wen, J., Bang, S., Park, S. and Song, S.Y. (2009) CD44-Positive Cells Are Responsible for Gemcitabine Resistance in Pancreatic Cancer Cells. International Journal of Cancer, 125, 2323-2331. [16] Ischenko, I., Seeliger, H., Jauch, K.W. and Bruns, C.J. (2009) Metastatic Activity and Chemotherapy Resistance in Human Pancreatic Cancer—Influence of Cancer Stem Cells. Surgery, 146, 430-434.
http://dx.doi.org/10.1016/j.surg.2009.05.003 [17] Li, C., Lee, C.J. and Simeone, D.M. (2009) Identification of Human Pancreatic Cancer Stem Cells. Methods in Molecular Biology, 568, 161-173.
http://dx.doi.org/10.1007/978-1-59745-280-9_10 [18] Niess, H., Camaj, P., Renner, A., et al. (2014) Side Population Cells of Pancreatic Cancer Show Characteristics of Cancer Stem Cells Responsible for Resistance and Metastasis. Targeted Oncology, 10, 215-227. [19] Hung, S.W., Mody, H.R. and Govindarajan, R. (2012) Overcoming Nucleoside Analog Chemoresistance of Pancreatic Cancer: A Therapeutic Challenge. Cancer Letters, 320, 138-149.
http://dx.doi.org/10.1016/j.canlet.2012.03.007 [20] Shah, A.N., Summy, J.M., Zhang, J., Park, S.I., Parikh, N.U. and Gallick, G.E. (2007) Development and Characterization of Gemcitabine-Resistant Pancreatic Tumor Cells. Annals of Surgical Oncology, 14, 3629-3637.
http://dx.doi.org/10.1245/s10434-007-9583-5 [21] Yan, X.D., Li, M., Yuan, Y., Mao, N. and Pan, L.Y. (2007) Biological Comparison of Ovarian Cancer Resistant Cell Lines to Cisplatin and Taxol by Two Different Administrations. Oncology Reports, 17, 1163-1169.
http://dx.doi.org/10.3892/or.17.5.1163 [22] Castellanos, J.A., Merchant, N.B. and Nagathihalli, N.S. (2013) Emerging Targets in Pancreatic Cancer: Epithelial- Mesenchymal Transition and Cancer Stem Cells. OncoTargets and Therapy, 6, 1261-1267.
[1] Siegel, R.L., Miller, K.D. and Jemal, A. (2015) Cancer Statistics, 2015. CA: A Cancer Journal for Clinicians, 65, 5-29.
http://dx.doi.org/10.3322/caac.21254 [2] Siegel, R., Naishadham, D. and Jemal, A. (2013) Cancer Statistics, 2013. CA: A Cancer Journal for Clinicians, 63, 11- 30.
http://dx.doi.org/10.3322/caac.21166 [3] Jemal, A., Bray, F., Center, M.M., Ferlay, J., Ward, E. and Forman, D. (2011) Global Cancer Statistics. CA: A Cancer Journal for Clinicians, 61, 69-90.
http://dx.doi.org/10.3322/caac.20107 [4] Paulson, A.S., Tran Cao, H.S., Tempero, M.A. and Lowy, A.M. (2013) Therapeutic Advances in Pancreatic Cancer. Gastroenterology, 144, 1316-1326.
http://dx.doi.org/10.1053/j.gastro.2013.01.078 [5] Michl, P. and Gress, T.M. (2013) Current Concepts and Novel Targets in Advanced Pancreatic Cancer. Gut, 62, 317-326.
http://dx.doi.org/10.1136/gutjnl-2012-303588 [6] Burris 3rd, H.A., Moore, M.J., Andersen, J., et al. (1997) Improvements in Survival and Clinical Benefit with Gemcitabine as First-Line Therapy for Patients with Advanced Pancreas Cancer: A Randomized Trial. Journal of Clinical Oncology: Official Journal of the American Society of Clinical Oncology, 15, 2403-2413. [7] Kothari, N., Saif, M.W. and Kim, R. (2013) First-Line Treatment for Advanced Pancreatic Cancer. JOP: Journal of the Pancreas, 14, 129-132. [8] Long, J., Zhang, Y., Yu, X., et al. (2011) Overcoming Drug Resistance in Pancreatic Cancer. Expert Opinion on Therapeutic Targets, 15, 817-828.
http://dx.doi.org/10.1517/14728222.2011.566216 [9] Arumugam, T., Ramachandran, V., Fournier, K.F., et al. (2009) Epithelial to Mesenchymal Transition Contributes to Drug Resistance in Pancreatic Cancer. Cancer Research, 69, 5820-5828.
http://dx.doi.org/10.1158/0008-5472.CAN-08-2819 [10] Wu, Q., Miele, L., Sarkar, F.H. and Wang, Z. (2012) The Role of EMT in Pancreatic Cancer Progression. Pancreatic Disorders & Therapy, 2.
http://dx.doi.org/10.4172/2165-7092.1000e121 [11] Sarkar, F.H., Li, Y., Wang, Z. and Kong, D. (2009) Pancreatic Cancer Stem Cells and EMT in Drug Resistance and Metastasis. Minerva Chirurgica, 64, 489-500. [12] Hermann, P.C., Huber, S.L., Herrler, T., et al. (2007) Distinct Populations of Cancer Stem Cells Determine Tumor Growth and Metastatic Activity in Human Pancreatic Cancer. Cell Stem Cell, 1, 313-323.
http://dx.doi.org/10.1016/j.stem.2007.06.002 [13] Hage, C., Rausch, V., Giese, N., et al. (2013) The Novel C-Met Inhibitor Cabozantinib Overcomes Gemcitabine Resistance and Stem Cell Signaling in Pancreatic Cancer. Cell Death & Disease, 4, e627.
http://dx.doi.org/10.1038/cddis.2013.158 [14] Vaz, A.P., Ponnusamy, M.P., Rachagani, S., Dey, P., Ganti, A.K. and Batra, S.K. (2014) Novel Role of Pancreatic Differentiation 2 in Facilitating Self-Renewal and Drug Resistance of Pancreatic Cancer Stem Cells. British Journal of Cancer, 111, 486-496. [15] Hong, S.P., Wen, J., Bang, S., Park, S. and Song, S.Y. (2009) CD44-Positive Cells Are Responsible for Gemcitabine Resistance in Pancreatic Cancer Cells. International Journal of Cancer, 125, 2323-2331. [16] Ischenko, I., Seeliger, H., Jauch, K.W. and Bruns, C.J. (2009) Metastatic Activity and Chemotherapy Resistance in Human Pancreatic Cancer—Influence of Cancer Stem Cells. Surgery, 146, 430-434.
http://dx.doi.org/10.1016/j.surg.2009.05.003 [17] Li, C., Lee, C.J. and Simeone, D.M. (2009) Identification of Human Pancreatic Cancer Stem Cells. Methods in Molecular Biology, 568, 161-173.
http://dx.doi.org/10.1007/978-1-59745-280-9_10 [18] Niess, H., Camaj, P., Renner, A., et al. (2014) Side Population Cells of Pancreatic Cancer Show Characteristics of Cancer Stem Cells Responsible for Resistance and Metastasis. Targeted Oncology, 10, 215-227. [19] Hung, S.W., Mody, H.R. and Govindarajan, R. (2012) Overcoming Nucleoside Analog Chemoresistance of Pancreatic Cancer: A Therapeutic Challenge. Cancer Letters, 320, 138-149.
http://dx.doi.org/10.1016/j.canlet.2012.03.007 [20] Shah, A.N., Summy, J.M., Zhang, J., Park, S.I., Parikh, N.U. and Gallick, G.E. (2007) Development and Characterization of Gemcitabine-Resistant Pancreatic Tumor Cells. Annals of Surgical Oncology, 14, 3629-3637.
http://dx.doi.org/10.1245/s10434-007-9583-5 [21] Yan, X.D., Li, M., Yuan, Y., Mao, N. and Pan, L.Y. (2007) Biological Comparison of Ovarian Cancer Resistant Cell Lines to Cisplatin and Taxol by Two Different Administrations. Oncology Reports, 17, 1163-1169.
http://dx.doi.org/10.3892/or.17.5.1163 [22] Castellanos, J.A., Merchant, N.B. and Nagathihalli, N.S. (2013) Emerging Targets in Pancreatic Cancer: Epithelial- Mesenchymal Transition and Cancer Stem Cells. OncoTargets and Therapy, 6, 1261-1267.