scholarly journals NLRP1 Functions Downstream of the MAPK/ERK Signaling via ATF4 and Contributes to Acquired Targeted Therapy Resistance in Human Metastatic Melanoma

2020 ◽  
Vol 14 (1) ◽  
pp. 23
Author(s):  
Zili Zhai ◽  
Prasanna K. Vaddi ◽  
Jenny Mae Samson ◽  
Tomoya Takegami ◽  
Mayumi Fujita
Keyword(s):  
Targeted Therapy ◽  
Protein Kinase ◽  
Metastatic Melanoma ◽  
Therapy Resistance ◽  
Melanoma Cells ◽  
Erk Signaling ◽  
Erk Pathway ◽  
Drug Resistant ◽  
Downstream Effector ◽  
Resistant Cells

The BRAF V600E mutation leads to constitutive activation of the mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) pathway and its downstream effector responses. Uncovering the hidden downstream effectors can aid in understanding melanoma biology and improve targeted therapy efficacy. The inflammasome sensor, NACHT, LRR, and PYD domains-containing protein 1 (NLRP1), is responsible for IL-1β maturation and itself is a melanoma tumor promoter. Here, we report that NLRP1 is a downstream effector of MAPK/ERK signaling through the activating transcription factor 4 (ATF4), creating regulation in metastatic melanoma cells. We confirmed that the NLRP1 gene is a target of ATF4. Interestingly, ATF4/NLRP1 regulation by the MAPK/ERK pathway uses distinct mechanisms in melanoma cells before and after the acquired resistance to targeted therapy. In parental cells, ATF4/NLRP1 is regulated by the MAPK/ERK pathway through the ribosomal S6 kinase 2 (RSK2). However, vemurafenib (VEM) and trametinib (TRA)-resistant cells lose the signaling via RSK2 and activate the cAMP/protein kinase A (PKA) pathway to redirect ATF4/NLRP1. Therefore, NLRP1 expression and IL-1β secretion were downregulated in response to VEM and TRA in parental cells but enhanced in drug-resistant cells. Lastly, silencing NLRP1 in drug-resistant cells reduced their cell growth and inhibited colony formation. In summary, we demonstrated that NLRP1 functions downstream of the MAPK/ERK signaling via ATF4 and is a player of targeted therapy resistance in melanoma. Targeting NLRP1 may improve the therapeutic efficacy of targeted therapy in melanoma.

scholarly journals Deregulated FASN Expression in BRAF Inhibitor-Resistant Melanoma Cells Unveils New Targets for Drug Combinations

Cancers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 2284
Author(s):  
Serena Stamatakos ◽  
Giovanni Luca Beretta ◽  
Elisabetta Vergani ◽  
Matteo Dugo ◽  
Cristina Corno ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Metastatic Melanoma ◽  
Mutant Cell ◽  
Braf Inhibitor ◽  
Cancer Cell Line ◽  
Melanoma Cells ◽  
Melanoma Progression ◽  
Increased Sensitivity ◽  
Resistant Cells

Metabolic changes promoting cell survival are involved in metastatic melanoma progression and in the development of drug resistance. In BRAF-inhibitor resistant melanoma cells, we explored the role of FASN, an enzyme involved in lipogenesis overexpressed in metastatic melanoma. Resistant melanoma cells displaying enhanced migratory and pro-invasive abilities increased sensitivity to the BRAF inhibitor PLX4032 upon the molecular targeting of FASN and upon treatment with the FASN inhibitor orlistat. This behavior was associated with a marked apoptosis and caspase 3/7 activation observed for the drug combination. The expression of FASN was found to be inversely associated with drug resistance in BRAF-mutant cell lines, both in a set of six resistant/sensitive matched lines and in the Cancer Cell Line Encyclopedia. A favorable drug interaction in resistant cells was also observed with U18666 A inhibiting DHCR24, which increased upon FASN targeting. The simultaneous combination of the two inhibitors showed a synergistic interaction with PLX4032 in resistant cells. In conclusion, FASN plays a role in BRAF-mutated melanoma progression, thereby creating novel therapeutic opportunities for the treatment of melanoma.

scholarly journals Autocrine Signaling of NRP1 Ligand Galectin-1 Elicits Resistance to BRAF-Targeted Therapy in Melanoma Cells

Cancers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2218
Author(s):  
Sabrina Rizzolio ◽  
Simona Corso ◽  
Silvia Giordano ◽  
Luca Tamagnone
Keyword(s):  
Targeted Therapy ◽  
Kinase Inhibitors ◽  
Combined Treatment ◽  
Melanoma Cells ◽  
Drug Resistant ◽  
Braf Inhibitors ◽  
Autocrine Signaling ◽  
Melanoma Tumor ◽  
Neuropilin 1 ◽  
Soluble Ligand

Melanoma cells addicted to mutated BRAF oncogene activity can be targeted by specific kinase inhibitors until they develop resistance to therapy. We observed that the expression of Galectin-1 (Gal-1), a soluble ligand of Neuropilin-1 (NRP1), is upregulated in melanoma tumor samples and melanoma cells resistant to BRAF-targeted therapy. We then demonstrated that Gal-1 is a novel driver of resistance to BRAF inhibitors in melanoma and that its activity is linked to the concomitant upregulation of the NRP1 receptor observed in drug-resistant cells. Mechanistically, Gal-1 sustains increased expression of NRP1 and EGFR in drug-resistant melanoma cells. Moreover, consistent with its role as a NRP1 ligand, Gal-1 negatively controls p27 levels, a mechanism previously found to enable EGFR upregulation in cancer cells. Finally, the combined treatment with a Gal-1 inhibitor and a NRP1 blocking drug enabled resistant melanoma cell resensitization to BRAF-targeted therapy. In summary, we found that the activation of Galectin-1/NRP1 autocrine signaling is a new mechanism conferring independence from BRAF kinase activity to oncogene-addicted melanoma cells.

scholarly journals Targeting CDC7 sensitizes resistance melanoma cells to BRAFV600E-specific inhibitor by blocking the CDC7/MCM2-7 pathway

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Shaimaa A. Gad ◽  
Hamdy E. A. Ali ◽  
Rofaida Gaballa ◽  
Rania M. Abdelsalam ◽  
Mourad Zerfaoui ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Metastatic Melanoma ◽  
Clinical Effect ◽  
Specific Inhibitor ◽  
Melanoma Cells ◽  
Development Of Resistance ◽  
Dual Targeting ◽  
Low Concentrations ◽  
Resistant Cells

Abstract Although the utilization of selective BRAFV600E inhibitors is associated with improved overall survival in patients with metastatic melanoma, a growing challenge of drug resistance has  emerged. CDC7 has been shown to be overexpressed and associated with poor prognosis in various cancers including melanoma. Thus, we aimed to elucidate the biological role of CDC7 in promoting Vemurafenib resistance and the anticipated benefits of dual targeting of BRAFV600E and CDC7 in melanoma cells. We performed exosomes-associated microRNA profiling and functional assays to determine the role of CDC7 in drug resistance using Vemurafenib-sensitive and resistant melanoma cells. Our results demonstrated that Vemurafenib-resistant cells exhibited a persistent expression of CDC7 in addition to prolonged activity of MCM2 compared to drug-sensitive cells. Reconstitution of miR-3613-3p in resistant cells downregulated CDC7 expression and reduced the number of colonies. Treatment of cells with low concentrations of CDC7 inhibitor TAK-931 sensitized resistant cells to Vemurafenib and reduced the number of cell colonies. Taken together, CDC7 overexpression and downregulation of miR-3613-3p were associated with Vemurafenib resistance in BRAFV600E- bearing melanoma cells. Dual targeting of CDC7 and BRAFV600E reduced the development of resistance against Vemurafenib. Further studies are warranted to investigate the clinical effect of targeting CDC7 in metastatic melanoma.

A randomized phase II study of vemurafenib plus cobimetinib continuous versus intermittent in previously untreated BRAF V600-mutation positive patients with unresectable locally advanced or metastatic melanoma.

2017 ◽  
Vol 35 (15_suppl) ◽  
pp. TPS9599-TPS9599 ◽  
Author(s):  
Jose A. Lopez-Martin ◽  
Alfonso Berrocal ◽  
María González-Cao
Keyword(s):  
Metastatic Melanoma ◽  
Phase Ii ◽  
Phase Ii Study ◽  
Mapk Pathway ◽  
Locally Advanced ◽  
Advanced Melanoma ◽  
Drug Resistant ◽  
Randomized Phase Ii ◽  
Melanoma Patients ◽  
Resistant Cells

TPS9599 Background: Previous clinical trials have shown that vemurafenib significantly increases PFS and OS in untreated BRAFV600 mutant advanced melanoma patients. Nevertheless, disease progression occurs after a median of 6-7 months since start of vemurafenib. Several mechanisms of acquired resistance to vemurafenib result in reactivation of MAPK pathway. Upfront addition of a MEK inhibitor (MEKi) to vemurafenib delays secondary resistance to BRAFi. The combination of cobimetinib, a MEKi, plus vemurafenib as a continuous administration was approved by FDA in 2,015 in untreated metastatic BRAFV600 advanced melanoma patients based on an increase in PFS and OS achieved in a phase III trial (coBRIM trial). Preclinical models have shown that continuous vemurafenib dosing promotes the clonal expansion of drug-resistant cells, and intermittent dosing could serve to eliminate the fitness advantage of the resistant cells and delay the onset of drug-resistant disease (Das Thakur, Nature 2013). These observations and some clinical case reports support upfront evaluation of alternative dosing regimens of MAPK pathway inhibition. Methods: This is a randomized phase II study to explore the efficacy and safety of two schedules of administration of vemurafenib in combination with cobimetinib (continuous – 28-day cycles with vemurafenib 960 mg PO BID, Days 1-28, and cobimetinib 60 mg PO QD, Days 1-21 – and intermittent – same dose/schedule during first 12 weeks, and then, same doses with the following schedule: vemurafenib 4 weeks on /2 weeks off, and cobimetinib 3 weeks on/ 3 weeks off), in patients with untreated, BRAFV600 mutated, unresectable, measurable (RECIST 1.1), locally advanced or metastatic melanoma. Prior adjuvant immunotherapy is allowed. Primary endpoint is PFS. Secondary endpoints include: OS, ORR, pharmacokinetic and pharmacodynamic profiles and safety. Additional translational research to analyze predictive factors and mechanism of resistance will be explored. The trial is in progress; 56 of up to 116 planned pts have been recruited at the end of December 2016 (enrollment started in June 2015). Clinical trial information: NCT02583516.

scholarly journals Rac Inhibition As A Novel Therapeutic Strategy for EGFR/HER2 Targeted Therapy Resistant Breast Cancer

2020 ◽  
Author(s):  
Luis D Borrero-Garcia ◽  
Maria del Mar Maldonado ◽  
Julia I Medina-Velázquez ◽  
Angel Troche-Torres ◽  
Luis Velazquez-Vega ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Targeted Therapy ◽  
Epithelial To Mesenchymal Transition ◽  
Point Mutations ◽  
Therapy Resistance ◽  
Small Gtpase ◽  
Mitogen Activated Protein Kinase ◽  
Intrinsic Resistance ◽  
Mesenchymal Transition ◽  
Resistant Cells

Abstract Background Even though targeted therapies are available for cancers expressing oncogenic epidermal growth receptor (EGFR) and (or) human EGFR2 (HER2), acquired or intrinsic resistance often confounds therapy success. Common mechanisms of therapy resistance involve activating receptor point mutations and (or) upregulation of signaling downstream of EGFR/HER2 to Akt and (or) mitogen activated protein kinase (MAPK) pathways. However, additional pathways of resistance may exist thus, confounding successful therapy. Methods To determine novel mechanisms of EGFR/HER2 therapy resistance in breast cancer, gefitinib or lapatinib resistant variants were created from SKBR3 breast cancer cells. Syngenic therapy sensitive and resistant SKBR3 variants were characterized for mechanisms of resistance by mammosphere assays, viability assays, and western blotting for total and phospho proteins. Results Gefitinib and lapatinib treatments reduced mammosphere formation in the parental cells, but not in the therapy resistant variants, indicating enhanced cancer stem cell-like and epithelial to mesenchymal transition (EMT) characteristics in therapy resistant cells. The therapy resistant variants did not show significant changes in established therapy resistant pathways of Akt and MAPK activities downstream of EGFR/HER2. However, these cells exhibited elevated expression and activation of the small GTPase Rac, which is a pivotal intermediate of GFR signaling in EMT and metastasis. Therefore, the potential of the Rac inhibitors EHop-016 and MBQ-167 to overcome therapy resistance was tested and found to inhibit viability and induce apoptosis of therapy resistant cells. Conclusions Rac inhibition may represent a viable strategy for treatment of EGFR/HER2 targeted therapy resistant breast cancer.

scholarly journals S100-EPISPOT: A New Tool to Detect Viable Circulating Melanoma Cells

Cells ◽  
2019 ◽  
Vol 8 (7) ◽  
pp. 755 ◽  
Author(s):  
Laure Cayrefourcq ◽  
Aurélie De Roeck ◽  
Caroline Garcia ◽  
Pierre-Emmanuel Stoebner ◽  
Fanny Fichel ◽  
...  
Keyword(s):  
Overall Survival ◽  
Metastatic Melanoma ◽  
Clinical Utility ◽  
S100 Protein ◽  
Melanoma Cells ◽  
Detection Methods ◽  
Drug Resistant ◽  
Poor Overall Survival ◽  
Homogeneous Population ◽  
Higher Sensitivity

Metastatic melanoma is one of the most aggressive and drug-resistant cancers with very poor overall survival. Circulating melanoma cells (CMCs) were first described in 1991. However, there is no general consensus on the clinical utility of CMC detection, largely due to conflicting results linked to the use of heterogeneous patient populations and different detection methods. Here, we developed a new EPithelial ImmunoSPOT (EPISPOT) assay to detect viable CMCs based on their secretion of the S100 protein (S100-EPISPOT). Then, we compared the results obtained with the S100-EPISPOT assay and the CellSearch® CMC kit using blood samples from a homogeneous population of patients with metastatic melanoma. We found that S100-EPISPOT sensitivity was significantly higher than that of CellSearch®. Specifically, the percentage of patients with ≥2 CMCs was significantly higher using S100-EPISPOT than CellSearch® (48% and 21%, respectively; p = 0.0114). Concerning CMC prognostic value, only the CellSearch® results showed a significant association with overall survival (p = 0.006). However, due to the higher sensitivity of the new S100-EPISPOT assay, it would be interesting to determine whether this functional test could be used in patients with non-metastatic melanoma for the early detection of tumor relapse and for monitoring the treatment response.

scholarly journals USP10 promotes proliferation and migration and inhibits apoptosis of endometrial stromal cells in endometriosis through activating the Raf-1/MEK/ERK pathway

2018 ◽  
Vol 315 (6) ◽  
pp. C863-C872 ◽  
Author(s):  
Qiong Chen ◽  
Yuanyuan Hang ◽  
Tingting Zhang ◽  
Li Tan ◽  
Shuangdi Li ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Signaling Pathway ◽  
Stromal Cells ◽  
Uterine Cavity ◽  
Mitogen Activated Protein Kinase ◽  
Erk Signaling ◽  
Erk Pathway ◽  
Endometrial Stromal Cells ◽  
And Migration ◽  
Proliferation And Migration

Endometriosis has been initially described as endometrial-like tissue outside of the uterine cavity. The mitogen-activated protein kinase/ERK kinase (MEK)/extracellular signal-regulated kinase (ERK) signaling pathway playing an important role in the regulation of cell proliferation, apoptosis, and migration has been found to be activated in endometriosis. However, regulation of the MEK/ERK signaling pathway in endometriosis has not been fully understood. In this study, primary-cultured endometrial stromal cells were collected from patients with endometriosis and healthy controls, and the proliferation, apoptosis, and migration of ectopic endometrial stromal cells transfected with ubiquitin-specific protease 10 (USP10)-small-interfering RNA (siRNA) or pLVX-Puro-USP10 with or without MEK inhibitor PD-98059 or exogenous signaling stimulation such as epidermal growth factor (EGF) were measured by CCK-8, flow cytometry, and Transwell, respectively. The gene and protein expressions were measured by real-time PCR or Western blot. USP10 overexpression promoted ectopic endometrial stromal cell migration and proliferation, suppressed cell apoptosis, and activated MEK/ERK signaling that is a critical downstream target of the serine/threonine protein kinase Raf-1, which was significantly blocked by PD-98059. USP10 silencing demonstrated the inverse effects, and these effects induced by USP10 silencing were significantly blocked by EGF. USP10 overexpression promoted Raf-1 protein expression, but not mRNA expression, through deubiquitination. In conclusion, these results suggest that USP10 promotes proliferation and migration and inhibits apoptosis of endometrial stromal cells in endometriosis through activating the Raf-1/MEK/ERK pathway.

scholarly journals Plasticity of Drug-Naïve and Vemurafenib- or Trametinib-Resistant Melanoma Cells in Execution of Differentiation/Pigmentation Program

2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Malgorzata Czyz ◽  
Malgorzata Sztiller-Sikorska ◽  
Anna Gajos-Michniewicz ◽  
Marta Osrodek ◽  
Mariusz L. Hartman
Keyword(s):  
Cell Lines ◽  
Melanoma Cell ◽  
Treated Patient ◽  
Melanoma Cells ◽  
Drug Resistant ◽  
Loss Of Function ◽  
Acquired Drug Resistance ◽  
Drug Naïve ◽  
Melanoma Cell Lines ◽  
Resistant Cells

Melanoma plasticity creates a plethora of opportunities for cancer cells to escape treatment. Thus, therapies must target all cancer cell subpopulations bearing the potential to contribute to disease. The role of the differentiation/pigmentation program in intrinsic and acquired drug resistance is largely uncharacterized. MITF level and expression of MITF-dependent pigmentation-related genes, MLANA, PMEL, TYR, and DCT, in drug-naïve and vemurafenib- or trametinib-treated patient-derived melanoma cell lines and their drug-resistant counterparts were analysed and referred to genomic alterations. Variability in execution of pigmentation/differentiation program was detected in patient-derived melanoma cell lines. Acute treatment with vemurafenib or trametinib enhanced expression of pigmentation-related genes in MITF-Mhigh melanoma cells, partially as the consequence of transcriptional reprograming. During development of resistance, changes in pigmentation program were not unidirectional, but also not universal as expression of different pigmentation-related genes was diversely affected. In selected resistant cell lines, differentiation/pigmentation was promoted and might be considered as one of drug-tolerant phenotypes. In other resistant lines, dedifferentiation was induced. Upon drug withdrawal (“drug holiday”), the dedifferentiation process in resistant cells either was enhanced but reversed by drug reexposure suggesting involvement of epigenetic mechanisms or was irreversible. The irreversible dedifferentiation might be connected with homozygous loss-of-function mutation in MC1R, as MC1RR151C  +/+ variant was found exclusively in drug-naïve MITF-Mlow dedifferentiated cells and drug-resistant cells derived from MITFhigh/MC1RWT cells undergoing irreversible dedifferentiation. MC1RR151C  +/+ variant might be further investigated as a parameter potentially impacting melanoma patient stratification and aiding in treatment decision.

scholarly journals Rac inhibition as a novel therapeutic strategy for EGFR/HER2 targeted therapy resistant breast cancer

BMC Cancer ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Luis D. Borrero-García ◽  
Maria del Mar Maldonado ◽  
Julia Medina-Velázquez ◽  
Angel L. Troche-Torres ◽  
Luis Velazquez ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Targeted Therapy ◽  
Point Mutations ◽  
Therapy Resistance ◽  
Small Gtpase ◽  
Mitogen Activated Protein Kinase ◽  
Intrinsic Resistance ◽  
Mammosphere Formation ◽  
Mitogen Activated Protein ◽  
Resistant Cells

Abstract Background Even though targeted therapies are available for cancers expressing oncogenic epidermal growth receptor (EGFR) and (or) human EGFR2 (HER2), acquired or intrinsic resistance often confounds therapy success. Common mechanisms of therapy resistance involve activating receptor point mutations and (or) upregulation of signaling downstream of EGFR/HER2 to Akt and (or) mitogen activated protein kinase (MAPK) pathways. However, additional pathways of resistance may exist thus, confounding successful therapy. Methods To determine novel mechanisms of EGFR/HER2 therapy resistance in breast cancer, gefitinib or lapatinib resistant variants were created from SKBR3 breast cancer cells. Syngenic therapy sensitive and resistant SKBR3 variants were characterized for mechanisms of resistance by mammosphere assays, viability assays, and western blotting for total and phospho proteins. Results Gefitinib and lapatinib treatments reduced mammosphere formation in the sensitive cells, but not in the therapy resistant variants, indicating enhanced mesenchymal and cancer stem cell-like characteristics in therapy resistant cells. The therapy resistant variants did not show significant changes in known therapy resistant pathways of AKT and MAPK activities downstream of EGFR/HER2. However, these cells exhibited elevated expression and activation of the small GTPase Rac, which is a pivotal intermediate of GFR signaling in EMT and metastasis. Therefore, the potential of the Rac inhibitors EHop-016 and MBQ-167 to overcome therapy resistance was tested, and found to inhibit viability and induce apoptosis of therapy resistant cells. Conclusions Rac inhibition may represent a viable strategy for treatment of EGFR/HER2 targeted therapy resistant breast cancer.

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