Abstract:Rare gain-of-function mutations in RAC1 drive drug resistance to targeted BRAF inhibition in cutaneous melanoma. Here, we show that wildtype RAC1 is a critical driver of growth and drug resistance, but only in a subset of melanomas with elevated markers of de-differentiation. Similarly, SRC inhibition also selectively sensitized de-differentiated melanomas to BRAF inhibition. One possible mechanism may be the suppression of the de-differentiated state, as SRC and RAC1 maintained markers of de-differentiation i… Show more
“…SFK induction during targeted therapy treatment has been described in multiple cancers, including melanoma; 30,31,32 our study sheds light on the kinetics associated with this response, revealing that signs of SFK induction can emerge as early as 3-6 hours of oncoprotein inhibition. This onset is markedly earlier than previously appreciated, suggesting a more immediate cellular adaptation to targeted therapy via this axis than previously appreciated.…”
Section: Discussionmentioning
confidence: 53%
“…SFKs constitute a group of non-receptor tyrosine kinases that coordinate important signaling events regulating cell morphology, survival, and metabolism, among many other biological processes, and have been linked to adaptation and resistance to targeted therapy. 30,31,32,33 Many of these phosphosites, in addition to other known SFK substrates which were not in SM-J or SM-K, were upregulated under VEM treatment after 72 hours compared to DMSO-treated cells, suggesting their induction was not a consequence of sustained culture. Notably, some of these sites did not show corresponding increases in transcript abundance, indicating that VEM treatment modulates SFK signaling by mechanisms that are at least partly uncoupled from transcriptional upregulation (Figure S4A).…”
A major contributor to poor sensitivity to anti-cancer kinase inhibitor therapy is drug-induced cellular adaptation, whereby remodeling of signaling and gene regulatory networks permits a drug-tolerant phenotype. Here, we resolve the scale and kinetics of critical subcellular events following oncogenic kinase inhibition and preceding cell cycle re-entry, using mass spectrometry-based phosphoproteomics and RNA sequencing to capture molecular snapshots within the first minutes, hours, and days of BRAF kinase inhibitor exposure in a humanBRAF-mutant melanoma model of adaptive therapy resistance. By enriching specific phospho-motifs associated with mitogenic kinase activity, we monitored the dynamics of thousands of growth- and survival-related protein phosphorylation events under oncogenic BRAF inhibition and drug removal. We observed early and sustained inhibition of the BRAF-ERK axis, gradual downregulation of canonical cell cycle-dependent signals, and three distinct and reversible phase transitions toward quiescence. Statistical inference of kinetically-defined signaling and transcriptional modules revealed a concerted response to oncogenic BRAF inhibition and a dominant compensatory induction of SRC family kinase (SFK) signaling, which we found to be at least partially driven by accumulation of reactive oxygen species via impaired redox homeostasis. This induction sensitized cells to co-treatment with an SFK inhibitor across a panel of patient-derived melanoma cell lines and in an orthotopic mouse xenograft model, underscoring the translational potential for measuring the early temporal dynamics of signaling and transcriptional networks under therapeutic challenge.
“…SFK induction during targeted therapy treatment has been described in multiple cancers, including melanoma; 30,31,32 our study sheds light on the kinetics associated with this response, revealing that signs of SFK induction can emerge as early as 3-6 hours of oncoprotein inhibition. This onset is markedly earlier than previously appreciated, suggesting a more immediate cellular adaptation to targeted therapy via this axis than previously appreciated.…”
Section: Discussionmentioning
confidence: 53%
“…SFKs constitute a group of non-receptor tyrosine kinases that coordinate important signaling events regulating cell morphology, survival, and metabolism, among many other biological processes, and have been linked to adaptation and resistance to targeted therapy. 30,31,32,33 Many of these phosphosites, in addition to other known SFK substrates which were not in SM-J or SM-K, were upregulated under VEM treatment after 72 hours compared to DMSO-treated cells, suggesting their induction was not a consequence of sustained culture. Notably, some of these sites did not show corresponding increases in transcript abundance, indicating that VEM treatment modulates SFK signaling by mechanisms that are at least partly uncoupled from transcriptional upregulation (Figure S4A).…”
A major contributor to poor sensitivity to anti-cancer kinase inhibitor therapy is drug-induced cellular adaptation, whereby remodeling of signaling and gene regulatory networks permits a drug-tolerant phenotype. Here, we resolve the scale and kinetics of critical subcellular events following oncogenic kinase inhibition and preceding cell cycle re-entry, using mass spectrometry-based phosphoproteomics and RNA sequencing to capture molecular snapshots within the first minutes, hours, and days of BRAF kinase inhibitor exposure in a humanBRAF-mutant melanoma model of adaptive therapy resistance. By enriching specific phospho-motifs associated with mitogenic kinase activity, we monitored the dynamics of thousands of growth- and survival-related protein phosphorylation events under oncogenic BRAF inhibition and drug removal. We observed early and sustained inhibition of the BRAF-ERK axis, gradual downregulation of canonical cell cycle-dependent signals, and three distinct and reversible phase transitions toward quiescence. Statistical inference of kinetically-defined signaling and transcriptional modules revealed a concerted response to oncogenic BRAF inhibition and a dominant compensatory induction of SRC family kinase (SFK) signaling, which we found to be at least partially driven by accumulation of reactive oxygen species via impaired redox homeostasis. This induction sensitized cells to co-treatment with an SFK inhibitor across a panel of patient-derived melanoma cell lines and in an orthotopic mouse xenograft model, underscoring the translational potential for measuring the early temporal dynamics of signaling and transcriptional networks under therapeutic challenge.
“…A375 and 451Lu can be distinguished from the other cell lines based on the expression of the de-differentiated transcriptional program. 46 Figure 3 Performance of candidates (A) Schematic of potential mechanisms by which candidates drive drug resistance. (B) Representative western blot with indicated antibodies in a panel of melanoma cell lines engineered to overexpress the screen candidates, empty vector (EM), VAV1, PDGFRB, or CSF1R.…”
Section: Resultsmentioning
confidence: 99%
“…We previously showed that overexpression of VAV1 increases RAC1 signaling and promotes drug resistance to BRAFi in cutaneous melanoma. 11 , 46 , 49 , 50 To determine the overlap between VAV1 and RAC1 signaling, we performed RNA-seq on A375 with enforced expression of VAV1 or RAC1 P29S ( Figure 4 A). The RAC1 P29S mutation is observed in ∼3% of cutaneous melanomas and encodes a hyperactive form of RAC1 that drives BRAFi resistance and metastasis in cutaneous melanoma.…”
“…Conventional tumor chemotherapy, which is most commonly applied as first-line therapy for cancer in the clinic, remains a formidable challenge due to the severe side effects and drug resistance (Alkhatib et al, 2022;Zhu et al, 2022a;Wang et al, 2022d;Kang et al, 2022). Through tremendous research by scientists, multifunctional nanozymes are proven to be a promising avenue to achieve higher tumor elimination efficacy in synergistic chemotherapy and catalytic therapy.…”
Nanozymes are nanomaterials with mimicked enzymatic activity, whose catalytic activity can be designed by changing their physical parameters and chemical composition. With the development of biomedical and material science, artificially created nanozymes have high biocompatibility and can catalyze specific biochemical reactions under biological conditions, thus playing a vital role in regulating physiological activities. Under pathological conditions, natural enzymes are limited in their catalytic capacity by the varying reaction conditions. In contrast, compared to natural enzymes, nanozymes have advantages such as high stability, simplicity of modification, targeting ability, and versatility. As a result, the novel role of nanozymes in medicine, especially in tumor therapy, is gaining increasing attention. In this review, function and application of various nanozymes in the treatment of cancer are summarized. Future exploration paths of nanozymes in cancer therapies based on new insights arising from recent research are outlined.
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