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Dermatology Commons

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Articles 1 - 6 of 6

Full-Text Articles in Dermatology

Slc36a1-Mtorc1 Signaling Drives Acquired Resistance To Cdk4/6 Inhibitors., Akihiro Yoshida, Yiwen Bu, Shuo Qie, John Wrangle, E. Ramsay Camp, E. Starr Hazard, Gary Hardiman, Renée De Leeuw, Karen E. Knudsen, J. Alan Diehl Sep 2019

Slc36a1-Mtorc1 Signaling Drives Acquired Resistance To Cdk4/6 Inhibitors., Akihiro Yoshida, Yiwen Bu, Shuo Qie, John Wrangle, E. Ramsay Camp, E. Starr Hazard, Gary Hardiman, Renée De Leeuw, Karen E. Knudsen, J. Alan Diehl

Department of Cancer Biology Faculty Papers

The cyclin-dependent kinase 4/6 (CDK4/6) kinase is dysregulated in melanoma, highlighting it as a potential therapeutic target. CDK4/6 inhibitors are being evaluated in trials for melanoma and additional cancers. While beneficial, resistance to therapy is a concern, and the molecular mechanisms of such resistance remain undefined. We demonstrate that reactivation of mammalian target of rapamycin 1 (mTORC1) signaling through increased expression of the amino acid transporter, solute carrier family 36 member 1 (SLC36A1), drives resistance to CDK4/6 inhibitors. Increased expression of SLC36A1 reflects two distinct mechanisms: (i) Rb loss, which drives SLC36A1 via reduced suppression of E2f; (ii) fragile X …


A Preexisting Rare Pik3ca E545k Subpopulation Confers Clinical Resistance To Mek Plus Cdk4/6 Inhibition In Nras Melanoma And Is Dependent On S6k1 Signaling, Gabriele Romano, Pei-Ling Chen, Ping Song, Jennifer L. Mcquade, Roger J. Liang, Mingguang Liu, Whijae Roh, Dzifa Y. Duose, Fernando C.L. Carapeto, Jun Li, Jessica L.F. Teh, Andrew A. Aplin, Merry Chen, Jianhua Zhang, Alexander J. Lazar, Michael A. Davies, P. Andrew Futreal, Rodabe N. Amaria, David Y. Zhang, Jennifer A. Wargo, Lawrence N. Kwong May 2018

A Preexisting Rare Pik3ca E545k Subpopulation Confers Clinical Resistance To Mek Plus Cdk4/6 Inhibition In Nras Melanoma And Is Dependent On S6k1 Signaling, Gabriele Romano, Pei-Ling Chen, Ping Song, Jennifer L. Mcquade, Roger J. Liang, Mingguang Liu, Whijae Roh, Dzifa Y. Duose, Fernando C.L. Carapeto, Jun Li, Jessica L.F. Teh, Andrew A. Aplin, Merry Chen, Jianhua Zhang, Alexander J. Lazar, Michael A. Davies, P. Andrew Futreal, Rodabe N. Amaria, David Y. Zhang, Jennifer A. Wargo, Lawrence N. Kwong

Department of Cancer Biology Faculty Papers

Combined MEK and CDK4/6 inhibition (MEKi + CDK4i) has shown promising clinical outcomes in patients with NRAS- mutant melanoma. Here, we interrogated longitudinal biopsies from a patient who initially responded to MEKi + CDK4i therapy but subsequently developed resistance. Whole-exome sequencing and functional validation identified an acquired PIK3CA E545K mutation as conferring drug resistance. We demonstrate that PIK3CA E545K preexisted in a rare subpopulation that was missed by both clinical and research testing, but was revealed upon multiregion sampling due to PIK3CA E545K being nonuniformly distributed. This resistant population rapidly expanded after the initiation of MEKi + CDK4i therapy and …


Inhibition Of Age-Related Therapy Resistance In Melanoma By Rosiglitazone-Mediated Induction Of Klotho., Reeti Behera, Amanpreet Kaur, Marie R. Webster, Suyeon Kim, Abibatou Ndoye, Curtis H. Kugel, Gretchen M. Alicea, Joshua Wang, Kanad Ghosh, Phil Cheng, Sofia Lisanti, Katie Marchbank, Vanessa Dang, Mitchell Levesque, Reinhard Dummer, Xiaowei Xu, Meenhard Herlyn, Andrew E. Aplin, Alexander Roesch, Cecilia Caino, Dario C. Altieri, Ashani T. Weeraratna Jun 2017

Inhibition Of Age-Related Therapy Resistance In Melanoma By Rosiglitazone-Mediated Induction Of Klotho., Reeti Behera, Amanpreet Kaur, Marie R. Webster, Suyeon Kim, Abibatou Ndoye, Curtis H. Kugel, Gretchen M. Alicea, Joshua Wang, Kanad Ghosh, Phil Cheng, Sofia Lisanti, Katie Marchbank, Vanessa Dang, Mitchell Levesque, Reinhard Dummer, Xiaowei Xu, Meenhard Herlyn, Andrew E. Aplin, Alexander Roesch, Cecilia Caino, Dario C. Altieri, Ashani T. Weeraratna

Department of Cancer Biology Faculty Papers

Purpose: Aging is a poor prognostic factor for melanoma. We have shown that melanoma cells in an aged microenvironment are more resistant to targeted therapy than identical cells in a young microenvironment. This is dependent on age-related secreted factors. Klotho is an age-related protein whose serum levels decrease dramatically by age 40. Most studies on klotho in cancer have focused on the expression of klotho in the tumor cell. We have shown that exogenous klotho inhibits internalization and signaling of Wnt5A, which drives melanoma metastasis and resistance to targeted therapy. We investigate here whether increasing klotho in the aged microenvironment …


Rac1 P29s Regulates Pd-L1 Expression In Melanoma., Ha Linh Vu, Sheera Rosenbaum, Timothy J. Purwin, Michael A. Davies, Andrew E. Aplin Sep 2015

Rac1 P29s Regulates Pd-L1 Expression In Melanoma., Ha Linh Vu, Sheera Rosenbaum, Timothy J. Purwin, Michael A. Davies, Andrew E. Aplin

Department of Cancer Biology Faculty Papers

Whole exome sequencing of cutaneous melanoma has led to the detection of P29 mutations in RAC1 in 5-9% of samples, but the role of RAC1 P29 mutations in melanoma biology remains unclear. Using reverse phase protein array analysis to examine the changes in protein/phospho-protein expression, we identified cyclin B1, PD-L1, Ets-1, and Syk as being selectively upregulated with RAC1 P29S expression and downregulated with RAC1 P29S depletion. Using the melanoma patient samples in TCGA, we found PD-L1 expression to be significantly increased in RAC1 P29S patients compared to RAC1 WT as well as other RAC1 mutants. The finding that PD-L1 …


Nf-Κb Regulation Of C-Flip Promotes Tnfα-Mediated Raf Inhibitor Resistance In Melanoma., Yongping Shao, Kaitlyn Le, Hanyin Cheng, Andrew E. Aplin Jul 2015

Nf-Κb Regulation Of C-Flip Promotes Tnfα-Mediated Raf Inhibitor Resistance In Melanoma., Yongping Shao, Kaitlyn Le, Hanyin Cheng, Andrew E. Aplin

Department of Cancer Biology Faculty Papers

Targeted inhibitors elicit heterogeneous clinical responses in genetically stratified groups of patients. Although most studies focus on tumor intrinsic properties, factors in the tumor microenvironment were recently found to modulate the response to inhibitors. Here, we show that in cutaneous BRAF V600E melanoma, the cytokine tumor necrosis factor-α (TNFα) blocks RAF inhibitor-induced apoptosis via activation of NF-κB. Several NF-κB-dependent factors are upregulated following TNFα and RAF inhibitor treatment. Of these factors, we show that death receptor inhibitor cellular caspase 8 (FLICE)-like inhibitory protein (c-FLIP) is required for TNFα-induced protection against RAF inhibitor. Overexpression of c-FLIP_S or c-FLIP_L isoform decreased RAF …


Mechanisms Of Resistance To Raf Inhibitors In Melanoma., A E Aplin, Fred M Kaplan, Yongping Shao Sep 2011

Mechanisms Of Resistance To Raf Inhibitors In Melanoma., A E Aplin, Fred M Kaplan, Yongping Shao

Department of Cancer Biology Faculty Papers

The recent RAF inhibitor trial with PLX4032/RG7204 in late-stage mutant B-RAF melanoma patients has been lauded as a success story for personalized cancer therapy since short-term clinical responses were observed in the majority of patients. However, initial responses were followed by subsequent tumor re-growth, and a subset of patients showed intrinsic resistance. Bi-directional translational efforts are now essential to determine the mechanisms underlying acquired/secondary and intrinsic resistance to RAF inhibitors.