Compressive Stimulation Enhances Ovarian Cancer Proliferation, Invasion, Chemoresistance, and Mechanotransduction via CDC42 in a 3D Bioreactor

Abstract

This report investigates the role of compressive stress on ovarian cancer in a 3D custom built bioreactor. Cells within the ovarian tumor microenvironment experience a range of compressive stimuli that contribute to mechanotransduction. As the ovarian tumor expands, cells are exposed to chronic load from hydrostatic pressure, displacement of surrounding cells, and growth induced stress. External dynamic stimuli have been correlated with an increase in metastasis, cancer stem cell marker expression, chemoresistance, and proliferation in a variety of cancers. However, how these compressive stimuli contribute to ovarian cancer progression is not fully understood. In this report, high grade serous ovarian cancer cell lines were encapsulated within an ECM mimicking hydrogel comprising of agarose and collagen type I, and stimulated with confined cyclic or static compressive stresses for 24 and 72 h. Compression stimulation resulted in a significant increase in proliferation, invasive morphology, and chemoresistance. Additionally, CDC42 was upregulated in compression stimulated conditions, and was necessary to drive increased proliferation and chemoresistance. Inhibition of CDC42 lead to significant decrease in proliferation, survival, and increased chemosensitivity. In summary, the dynamic in vitro 3D platform developed in this report, is ideal for understanding the influence of compressive stimuli, and can be widely applicable to any epithelial cancers. This work reinforces the critical need to consider compressive stimulation in basic cancer biology and therapeutic developments.

A flexible micro-piston device for mechanical cell stimulation and compression in microfluidic settings

“…This results is of particular interest, as chronic mechanical loading has been postulated to aid in ovarian cancer progression, forming a positive feedback loop [26]. Clearly, the e↵ects of cyclic compression require further study and applied cyclic pressures need to be expanded from the range of 3.9 to 6.5 kPa used by Novak et al [17] to the physiologically-relevant 3.7 to 18.9 kPa and above estimated to occur in human tumors [26,28].…”

“…As a result, the application of mechanical compression on living cells, such as cancerous [5,[9][10][11][12][13][14][15][16][17][18][19], non-cancerous and stromal cells [20][21][22], neurons [23] and chondrocytes [24], has gained importance in recent years. Compression applied on cancer types, such as breast [5,16,18,19], brain [13], pancreatic [9] and ovarian [17,25] cancer cells, resulted in more invasive and metastatic forms. While indicative, previous studies all point out the need for further investigations to understand the e↵ect of compressive mechanical stimuli in metastasis of di↵erent cancer types, for example ovarian cancer [17,25,26].…”

“…Asem et al [25] and Klymenko et al [27] applied static compression at ⇠3 kPa and at 3.18-3.53 kPa, respectively, on ovarian cancer models in o↵-chip settings. On the other hand, a recent work by Novak et al remains the only study to date using a bioreactor device, which is yet at millimeter scale, to investigate the e↵ect of compressive mechanical stress on ovarian cancer [17]. OV-CAR ovarian cancer cells were exposed to both static and cyclic compression, leading to increases in proliferation, invasive morphology and chemoresistance.…”

“…Compression applied on cancer types, such as breast [5, 16, 18, 19], brain [13], pancreatic [9] and ovarian [17, 25] cancer cells, resulted in more invasive and metastatic forms. While indicative, previous studies all point out the need for further investigations to understand the effect of compressive mechanical stimuli in metastasis of different cancer types, for example ovarian cancer [17, 25, 26]. Ovarian cancer cells are exposed to compressive stress mainly by tumor growth, native tissue and hydrostatic pressure from the ascites [25, 26].…”

“…Clearly, the effects of cyclic compression require further study and applied cyclic pressures need to be expanded from the range of 3.9 to 6.5 kPa used by Novak et al . [17] to the physiologically-relevant 3.7 to 18.9 kPa and above estimated to occur in human tumors [26, 28].…”