scholarly journals Mutant-selective degradation by BRAF-targeting PROTACs

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Shanique Alabi ◽  
Saul Jaime-Figueroa ◽  
Zhan Yao ◽  
Yijun Gao ◽  
John Hines ◽  
...  
Keyword(s):  
Acquired Resistance ◽  
Xenograft Model ◽  
Braf Inhibitor ◽  
Therapeutic Window ◽  
Missense Mutations ◽  
Cancer Cell Growth ◽  
Selective Degradation ◽  
Approved Drugs ◽  
Mutant Braf

AbstractOver 300 BRAF missense mutations have been identified in patients, yet currently approved drugs target V600 mutants alone. Moreover, acquired resistance inevitably emerges, primarily due to RAF lesions that prevent inhibition of BRAF V600 with current treatments. Therefore, there is a need for new therapies that target other mechanisms of activated BRAF. In this study, we use the Proteolysis Targeting Chimera (PROTAC) technology, which promotes ubiquitination and degradation of neo-substrates, to address the limitations of BRAF inhibitor-based therapies. Using vemurafenib-based PROTACs, we achieve low  nanomolar degradation of all classes of BRAF mutants, but spare degradation of WT RAF family members. Our lead PROTAC outperforms vemurafenib in inhibiting cancer cell growth and shows in vivo efficacy in a Class 2 BRAF xenograft model. Mechanistic studies reveal that BRAFWT is spared due to weak ternary complex formation in cells owing to its quiescent inactivated conformation, and activation of BRAFWT sensitizes it to degradation. This study highlights the degree of selectivity achievable with degradation-based approaches by targeting mutant BRAF-driven cancers while sparing BRAFWT, providing an anti-tumor drug modality that expands the therapeutic window.

scholarly journals Mutant-selective Degradation by BRAF-targeting PROTACs

2020 ◽  
Author(s):  
Shanique Alabi ◽  
Saul Jaime-Figueroa ◽  
Zhan Yao ◽  
Yijun Gao ◽  
John Hines ◽  
...  
Keyword(s):  
Acquired Resistance ◽  
Xenograft Model ◽  
Braf Inhibitor ◽  
Therapeutic Window ◽  
Missense Mutations ◽  
Cancer Cell Growth ◽  
Selective Degradation ◽  
Approved Drugs ◽  
Mutant Braf

AbstractOver 300 BRAF missense mutations have been identified in patients, yet currently approved drugs target V600 mutants alone. Moreover, acquired resistance inevitably emerges, primarily due to RAF lesions that prevent inhibition of BRAF V600 with current treatments. Therefore, there is a need for new therapies that target other mechanisms of activated BRAF. In this study, we use the Proteolysis Targeting Chimera (PROTAC) technology, which promotes ubiquitination and degradation of neo-substrates, to address the limitations of BRAF inhibitor-based therapies. Using vemurafenib-based PROTACs, we successfully achieve sub-nanomolar degradation of all classes of BRAF mutants, but spare degradation of WT RAF family members. Our lead PROTAC outperforms vemurafenib in inhibiting cancer cell growth and shows in vivo efficacy in a Class 2 BRAF xenograft model. Mechanistic studies reveal that BRAFWT is spared due to weak ternary complex formation in cells owing to its quiescent inactivated conformation, and activation of BRAFWT sensitizes it to degradation. This study highlights the degree of selectivity achievable using degradation-based therapies by targeting mutant BRAF-driven cancers while sparing BRAFWT and thus expanding the therapeutic window using a new anti-tumor drug modality.

scholarly journals PERK mediates resistance to BRAF inhibition in melanoma with impaired PTEN

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Yifei Qin ◽  
Qiang Zuo ◽  
Lei Huang ◽  
Liping Huang ◽  
Glenn Merlino ◽  
...  
Keyword(s):  
Critical Role ◽  
Acquired Resistance ◽  
Braf Inhibitor ◽  
Treatment Needs ◽  
Braf Inhibition ◽  
Melanoma Treatment ◽  
Pten Inhibition ◽  
Mutant Braf

AbstractTargeting mutant BRAF in patients with melanomas harboring this oncogene has been highly successful as a first-line treatment, but other mutations may affect its efficacy and alter the route of acquired resistance resulting in recurrence and poor prognosis. As an evolving strategy, melanoma treatment needs to be expanded to include targets based on newly discovered emerging molecules and pathways. We here show that PERK plays a critical role in BRAF inhibitor-acquired resistance in melanoma with impaired PTEN. Inhibition of PERK by either shRNA or a pharmacological inhibitor blocked the growth of BRAF inhibitor-resistant melanoma with impaired PTEN in vitro and in vivo, suggesting an effective approach against melanomas with mutant BRAF and PTEN deficiency. Our current findings, along with our previous discovery that the AXL/AKT axis mediates resistance to BRAF inhibition in melanoma with wild-type PTEN, provide new insights toward a strategy for combating BRAF inhibition-acquired resistance in BRAF mutant melanoma with different PTEN statuses.

scholarly journals Clarithromycin synergizes with cisplatin to inhibit ovarian cancer growth in vitro and in vivo

2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Bo Zhou ◽  
Meng Xia ◽  
Bin Wang ◽  
Niresh Thapa ◽  
Lijuan Gan ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Acquired Resistance ◽  
Xenograft Model ◽  
Annexin V ◽  
Therapy Resistance ◽  
Tumor Xenograft ◽  
Cancer Cell Growth ◽  
Cisplatin Therapy

Abstract Background Cisplatin-based chemotherapy is the first-line treatment for ovarian cancer. However, acquired resistance to cisplatin treatment often occurs in epithelial ovarian cancer, and effective and practical methods for overcoming this obstacle are urgently needed. The study aimed to demonstrate the synergistic effect of clarithromycin (CAM) with cisplatin to inhibit ovarian carcinoma cells growth in vitro and in vivo. Results We performed CCK-8 assay to detect apoptosis rates in response to CAM alone or in combination with cisplatin, which were further confirmed by Annexin V and PI staining methods and western blotting. Mechanistically, CAM could reduce endogenous antioxidant enzyme expression and increase the levels of reactive oxygen species (ROS) to augment the cytotoxic effect of cisplatin. Meanwhile, a tumor xenograft model in athymic BALB/c-nude mice demonstrated that CAM combined with cisplatin resulted in reduced tumor growth and weight compared with cisplatin alone. Conclusion Collectively, our results indicate that CAM works synergistically with cisplatin to inhibit ovarian cancer cell growth, which may be manipulated by a ROS-mediated mechanism that enhances cisplatin therapy, and offers a novel strategy for overcoming cisplatin therapy resistance.

Highly Potent rhenium(I) Tricarbonyl Complexes with Dual Anticancer and Anti-Angiogenic Activity Against Colorectal Carcinoma

2020 ◽  
Author(s):  
Joachim Delasoie ◽  
Aleksandar Pavic ◽  
Noémie Voutier ◽  
Sandra Vojnovic ◽  
Aurélien Crochet ◽  
...  
Keyword(s):  
Colorectal Carcinoma ◽  
Anticancer Drugs ◽  
Xenograft Model ◽  
Therapeutic Window ◽  
Low Doses ◽  
Sunitinib Malate ◽  
Angiogenic Activity ◽  
Antimetastatic Activity ◽  
Clinical Drugs

Synthesized and characterized a series of rhenium(I) trycarbonyl-based complexes with increased lipophilicity. Two of these novel compounds were discovered to possess remarkable anticancer, anti-angiogenic and antimetastatic activity <i>in vivo</i> (zebrafish-human CRC xenograft model), being effective at very low doses (1-3 µM). At doses as high as 250 µM the complexes did not provoke toxicity issues encountered in clinical anticancer drugs (cardio-, hepato-, and myelotoxicity). The two compounds exceed the antiproliferative and anti-angiogenic potency of clinical drugs cisplatin and sunitinib-malate, and display a large therapeutic window.

scholarly journals Highly Potent Rhenium(I) Tricarbonyl Complexes with Dual Anticancer and Anti-Angiogenic Activity Against Colorectal Carcinoma

2020 ◽  
Author(s):  
Joachim Delasoie ◽  
Aleksandar Pavic ◽  
Noémie Voutier ◽  
Sandra Vojnovic ◽  
Aurélien Crochet ◽  
...  
Keyword(s):  
Colorectal Carcinoma ◽  
Anticancer Drugs ◽  
Xenograft Model ◽  
Therapeutic Window ◽  
Low Doses ◽  
Sunitinib Malate ◽  
Angiogenic Activity ◽  
Antimetastatic Activity ◽  
Clinical Drugs

Synthesized and characterized a series of rhenium(I) trycarbonyl-based complexes with increased lipophilicity. Two of these novel compounds were discovered to possess remarkable anticancer, anti-angiogenic and antimetastatic activity <i>in vivo</i> (zebrafish-human CRC xenograft model), being effective at very low doses (1-3 µM). At doses as high as 250 µM the complexes did not provoke toxicity issues encountered in clinical anticancer drugs (cardio-, hepato-, and myelotoxicity). The two compounds exceed the antiproliferative and anti-angiogenic potency of clinical drugs cisplatin and sunitinib-malate, and display a large therapeutic window.

Evaluation of indibulin, a novel tubulin targeting-agent, in combination with capecitabine, with mathematically optimized dose scheduling

2009 ◽  
Vol 27 (15_suppl) ◽  
pp. 2538-2538
Author(s):  
J. J. Lewis ◽  
M. D. Galsky ◽  
L. H. Camacho ◽  
D. M. Loesch ◽  
P. B. Komarnitsky ◽  
...  
Keyword(s):  
Breast Carcinoma ◽  
Acquired Resistance ◽  
Optimal Schedule ◽  
Xenograft Model ◽  
Preliminary Evidence ◽  
Clinical Activity ◽  
Drug Induced ◽  
Dose Levels

2538 Background: Indibulin (IDB) is a novel, orally available tubulin-targeting molecule that perturbs cancer cell migration and mitosis. It is active against taxane-resistant cell lines and is synergistic with 5-FU in vitro and in vivo. Two translational studies have been conducted: a Phase IB study of IDB in combination with capecitabine (CAP) in patients with advanced solid tumors, and mathematical modeling applying Norton-Simon models to breast carcinoma MX-1 xenografts to further develop Phase II dose. Methods: IDB is administered continuously starting at 400 mg BID. CAP is administered for 2 weeks with 1 week rest, starting at 875 mg/m2 BID. IDB and CAP are escalated to MTD: IDB 600 mg BID & CAP 1000 mg/m2 BID. Efficacy is evaluated every 9 weeks using RECIST. In the xenograft model indibulin is administered at dose levels from 12 to 28.7 mg/kg/day to nude mice carrying MX-1 breast carcinoma. Tumor growth is analyzed using a Gompertzian-type growth model to determine via calculus of variations the optimal schedule to maximize the efficacy/toxicity ratio. Results: To date, 7 patients have been treated and are evaluable for safety. Median age 62 yrs; ECOG ≤1; median prior therapies 3. Four patients are evaluable for efficacy and all have stable disease (3 for 6 cycles, 1 for 3 cycles). AEs include hand-and-foot syndrome (CAP), fatigue, vomiting, anorexia, and headache. Neither DLTs nor grade ≥3 AEs have been observed. In MX-1 xenografts, indibulin demonstrates linear dose-efficacy relationship over the range of 12 to 22 mg/kg. At all dose levels the first 5 days of administration are associated with a rapid accumulation of anticancer effect with lesser effects over the next 5 days to a peak of efficacy at day 10 Conclusions: IDB + CAP is well tolerated, without neurotoxicity. There is preliminary evidence of clinical activity even with this sub-optimal, continuous schedule of IDB. Formal analyses suggest that an intermittent schedule could optimize efficacy, minimize acquired resistance and allow for host recovery from drug-induced toxicity. Pre- clinical evaluation in a breast cancer model supports an intermittent dosing schedule to further increase the activity of IDB. [Table: see text]

scholarly journals miR-223 overexpression inhibits doxorubicin-induced autophagy by targeting FOXO3a and reverses chemoresistance in hepatocellular carcinoma cells

2019 ◽  
Vol 10 (11) ◽  
Author(s):  
Yue Zhou ◽  
Enjiang Chen ◽  
Yuexiao Tang ◽  
Jiayan Mao ◽  
Jian Shen ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Acquired Resistance ◽  
Xenograft Model ◽  
Term Therapy ◽  
Autophagic Flux ◽  
Doxorubicin Resistance ◽  
Novel Mirna ◽  
Mouse Xenograft Model ◽  
Hcc Cells

Abstract Doxorubicin is conventionally used in chemotherapy against hepatocellular carcinoma (HCC), but acquired resistance developed during long-term therapy limits its benefits. Autophagy, a conserved catabolic process for cellular self-protection and adaptation to the changing environment, is regarded as a potential clinical target to overcome doxorubicin resistance. In this study, the potential role of miR-223 in modulating doxorubicin-induced autophagy and sensitivity were evaluated in four transfected human HCC cell lines, and the in vivo relevance was assessed using a mouse xenograft model of HCC. We found that the well-defined miR-223 is expressed at low levels in doxorubicin treated HCC cells and that miR-223 overexpression inhibits the doxorubicin-induced autophagy that contributes to chemoresistance. Blockade of autophagic flux by chloroquine resulted in the failure of miR-223 inhibitor to suppress doxorubicin sensitivity of HCC cells. We further identified FOXO3a as a direct downstream target of miR-223 and primary mediator of the regulatory effect of miR-223 on doxorubicin-induced autophagy and chemoresistance in HCC cells. Finally, we confirmed the enhancement of doxorubicin sensitivity by agomiR-223 in xenograft models of HCC. These findings establish a novel miRNA-based approach for autophagy interference to reverse doxorubicin resistance in future chemotherapy regimens against human HCC.

scholarly journals Biogenic selenium nanoparticles produced by Lactobacillus casei ATCC393 inhibit colon cancer cell growth in vitro and in vivo

2021 ◽  
Author(s):  
Katerina Spyridopoulou ◽  
Eleni Tryfonopoulou ◽  
Georgios Aindelis ◽  
Petros Ypsilantis ◽  
Charalampos Sarafidis ◽  
...  
Keyword(s):  
Lactobacillus Casei ◽  
Colon Cancer Cell ◽  
Selenium Nanoparticles ◽  
Therapeutic Window ◽  
Cancer Cell Growth ◽  
Selenium Compounds ◽  
Anticancer Properties ◽  
Biogenic Selenium Nanoparticles

Selenium compounds exhibit excellent anticancer properties but have a narrow therapeutic window. Selenium nanoparticles however, are less toxic compared to other selenium forms, and their biogenic production leads to improved...

scholarly journals LMD-07. In Vitro AND In Vivo Culture of Patient Derived-Cerebral Spinal Fluid-Circulating Tumor Cells (PD-CSF-CTCs) in Leptomeningeal Disease (LMD) From Melanoma to Identify Novel Treatment Strategies

2021 ◽  
Vol 3 (Supplement_3) ◽  
pp. iii8-iii8
Author(s):  
Vincent Law ◽  
Zhihua Chen ◽  
Inna Smalley ◽  
Francesca Vena ◽  
Robert Macaulay ◽  
...  
Keyword(s):  
Cell Line ◽  
Treatment Strategies ◽  
Xenograft Model ◽  
Braf Inhibitor ◽  
Mek Inhibitor ◽  
P Value ◽  
Leptomeningeal Disease ◽  
In Vivo Culture

Abstract Background Approximately 5% of melanoma patients (pts) will develop LMD. Currently there is no effective treatments for this disease. A significant barrier to the development of effective therapies has been the inability to culture CSF-CTCs for functional analysis. For the first time, we were able to successfully expand CSF-CTCs in vitro and in vivo. We assessed gene signatures of PD-CSF-CTCs to determine novel targets for therapy. As a proof of concept, we tested the efficacy of combining ceritinib (cer), an IGF-1R inhibitor and trametinib (tra), a MEK inhibitor, against LMD. Methods CSF from 11 pts were collected from various sources (ie: LPs, Ommayas, rapid autopsies). PD-CSF-CTCs were expanded in vitro in conditioned media and in vivo using cell line-derived xenograft model. Single-cell RNA-sequencing (scRNAseq) analysis was performed to assess transcriptional profiles of PD-CSF-CTCs. Results Of the total 61 PD-CSF-CTCs collected from 11 pts (avg: 4.07 CSF collections/patient), we successfully cultured PD-CSF-CTCs from 3 pts (20%) and were able to grow them in vivo from 2 pts (18%). scRNAseq identified IGF-1R, Sox9, ErbB3 and MLANA were among the enriched genes for PD-CSF-CTCs. IGF-1R inhibition by cer and depletion by CRISPR suppressed cell growth. We evaluated the responses of cer + tra treatment in vitro and found that combining these agents produced drug synergy against PD-CSF-CTCs and resensitized BRAF inhibitor-resistant melanoma cell line, WM164R. In vivo LMD xenograft model showed cer + tra treatment significantly prolonged median survival of PD-CSF-CTCs LMD (control: 27 days vs treatment: 38.5 days; P value &lt; 0.032) and WM164R LMD (control: 35 days vs treatment: MS not reached; P value &lt; 0.047). Conclusions Though the sample size is small, this is the first report of the successful in vitro and in vivo culture of CSF-CTCs from pts with LMD.

In vivo activity of R1530 (R) alone and in combination with docetaxel (D) and bevacizumab (B) in a prostate carcinoma (PCa) xenograft model

2009 ◽  
Vol 27 (15_suppl) ◽  
pp. e16124-e16124
Author(s):  
K. D. Kolinsky ◽  
Y. Zhang ◽  
K. Packman ◽  
B. Higgins
Keyword(s):  
Xenograft Model ◽  
Optimal Dose ◽  
P Value ◽  
Clinical Testing ◽  
Cancer Cell Growth ◽  
Multikinase Inhibitor ◽  
R And D ◽  
Final Study ◽  
M Phase

e16124 Background: R is a multikinase inhibitor currently in phase I clinical testing. Its inhibitory profile includes several kinases that play critical roles in cancer cell growth and division leading to disruption at M-phase and antiangiogenic effects. Studies were conducted to evaluate the efficacy and tolerability of R alone and in combination with D and B in the 22rv1 androgen independent PCa model. Methods: Initially TGI of optimal dose (OD) R, D and B were evaluated. Then the TGI and increased life span (ILS) of the minimum efficacious dose (MED) and 2/3 OD R ± 2/3 OD D was tested. A final study compared doublets of 2/3 OD R + 2/3 OD D, 2/3 OD D + OD B, 2/3 OD R + OD B, and triplet of 2/3 OD D + 2/3 OD R+ 2/3 OD B. Results: All treatment groups were tolerated and there was no antagonism. TGI and ILS results are listed below ( Table ). Conclusions: The OD of R B and D showed monotherapy TGI in this model. MED R + 2/3 OD D gave ILS statistically better (sb) than singlets but TGI was sb than MED R but not the D singlet. 2/3 OD R + 2/3 OD D produced sb TGI and ILS than each singlet. TGI and ILS with 2/3 OD R is sb than 2/3 OD D. TGI and ILS of 2/3 OD R + 2/3 OD D was sb than the 2/3 OD D + OD B but not the 2/3 OD R + B doublet. TGI and ILS was sb for 2/3 OD R + OD B versus 2/3 OD D + OD B. The TGI of the triplet was equivalent to the 2/3 OD R + 2/3 OD D doublet, but ILS was sb in the triplet. Also, the TGI and ILS was sb for triplet versus 2/3 OD D + OD B. TGI and ILS of the triplet was equal to 2/3 OD R + OD B. In general, the results demonstrate that the shared mechanism of mitotic disruption by R and D do not render antagonism, but in fact, allow for potentiated TGI and ILS. Also of note is the equally superior TGI and ILS provided by R + B and R + B + D. In general, the preclinical results generated support clinical testing of these agents in PCa. * p value for all. [Table: see text] [Table: see text]

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