EGFR signaling pathways are wired differently in normal 184A1L5 human mammary epithelial and MDA-MB-231 breast cancer cells

Abstract

Because of differences in the downstream signaling patterns of its pathways, the role of the human epidermal growth factor family of receptors (HER) in promoting cell growth and survival is cell line and context dependent. Using two model cell lines, we have studied how the regulatory interaction network among the key proteins of HER signaling pathways may be rewired upon normal to cancerous transformation. We in particular investigated how the transcription factor STAT3 and several key kinases' involvement in cancer-related signaling processes differ between normal 184A1L5 human mammary epithelial (HME) and MDA-MB-231 breast cancer epithelial cells. Comparison of the responses in these cells showed that normal-to-cancerous cellular transformation causes a major re-wiring of the growth factor initiated signaling. In particular, we found that: i) regulatory interactions between Erk, p38, JNK and STAT3 are triangulated and tightly coupled in 184A1L5 HME cells, and ii) STAT3 is only weakly associated with the Erk-p38-JNK pathway in MDA-MB-231 cells. Utilizing the concept of pathway substitution, we predicted how the observed differences in the regulatory interactions may affect the proliferation/survival and motility responses of the 184A1L5 and MDA-MB-231 cells when exposed to various inhibitors. We then validated our predictions experimentally to complete the experimentcomputation-experiment iteration loop. Validated differences in the regulatory interactions of the 184A1L5 and MDA-MB-231 cells indicated that instead of inhibiting STAT3, which has severe toxic side effects, simultaneous inhibition of JNK together with Erk or p38 could be a more effective strategy to impose cell death selectively to MDA-MB-231 cancer cells while considerably lowering the side effects to normal epithelial cells. Presented analysis establishes a framework with examples that would enable cell signaling researchers to identify the signaling network structures which can be used to predict the phenotypic responses in particular cell lines of interest.

miR‑9 depletion suppresses the proliferation of osteosarcoma cells by targeting p16

“…Researchers have demonstrated that ERK/p38/JNK pathway involves the regulation of the proliferation, differentiation, apoptosis and metastasis of various cancer cells (23,24,28,29). Wang et al confirmed that miR-155 increases OS cell growth by regulating MAPK signaling (59).…”

“…Studies have confirmed that MAPKs exist in the majority of cells, and are associated with the proliferation, differentiation and apoptosis of various cells (25-27). Three different MAPK signaling pathways, including p38 MAPK, c-Jun N-terminal kinase (JNK) and extracellular signal-regulated kinase (ERK) (28,29), have been found in mammals. A number of studies have confirmed that these 3 signals can regulate the progression of various types of tumors, for example, OS, prostate cancer and glioma (30-32).…”

Impact of measurement noise, experimental design, and estimation methods on Modular Response Analysis based network reconstruction

“…However, the problem of network reconstruction from experimental data remains a challenging task, for which many different approaches have been suggested. Among those, Modular Response Analysis (MRA) has been proven successful in many applications 1 – 4 . MRA uses steady-state data of experiments in which each node of a network is perturbed successively (see Fig.…”

STAT3 Knockdown Induces Tumor Formation by MDA-MB-231 Cells

“…STAT3 protein expression and phosphorylation at tyrosine (Y705) and serine (S727) sites were measured using western blots [ 18 ]. Briefly cells at 75% confluency were lysed using RIPA buffer with protease and phosphatase inhibitors.…”

“…Membranes were developed using chemiluminescence ECL reagent (Thermofisher Scientific, cat # 34095). Western blot images were captured with a LI-COR C-Digit scanner and protein band intensities were measured and analysed using LI-COR Image Studio Digits v3.1 software [ 18 ].…”