scholarly journals Activation of Grm1 expression by mutated BRaf (V600E) in vitro and in vivo

Oncotarget ◽  
2017 ◽  
Vol 9 (5) ◽  
pp. 5861-5875 ◽  
Author(s):  
Ho-Chung Chen ◽  
Jairo Sierra ◽  
Lumeng Jenny Yu ◽  
Robert Cerchio ◽  
Brian A. Wall ◽  
...  
Keyword(s):  
2017 ◽  
Author(s):  
Barbara Oldrini ◽  
Álvaro Curiel-García ◽  
Carolina Marques ◽  
Veronica Matia ◽  
Özge Uluçkan ◽  
...  

AbstractIt has been gradually established that the vast majority of human tumors are extraordinarily heterogeneous at a genetic level. To accurately recapitulate this complexity, it is now evident that in vivo animal models of cancers will require to recreate not just a handful of simple genetic alterations, but possibly dozens and increasingly intricate. Here, we have combined the RCAS/TVA system with the CRISPR/Cas9 genome editing tools for precise modeling of human tumors. We show that somatic deletion in neural stem cells (NSCs) of a variety of known tumor suppressor genes (Trp53, Cdkn2a and Pten), in combination with the expression of an oncogene driver, leads to high-grade glioma formation. Moreover, by simultaneous delivery of pairs of guide RNAs (gRNAs) we generated different gene fusions, either by chromosomal deletion (Bcan-Ntrk1) or by chromosomal translocation (Myb-Qk), and we show that they have transforming potential in vitro and in vivo. Lastly, using homology-directed-repair (HDR), we also produced tumors carrying the Braf V600E mutation, frequently identified in a variety of subtypes of gliomas. In summary, we have developed an extremely powerful and versatile mouse model for in vivo somatic genome editing, that will elicit the generation of more accurate cancer models particularly appropriate for pre-clinical testing.


2021 ◽  
Vol 12 ◽  
Author(s):  
Hongmei Cui ◽  
Qinghui Wang ◽  
Duane D. Miller ◽  
Wei Li

Melanoma is one of the deadliest skin cancers having a five-year survival rate around 15–20%. An overactivated MAPK/AKT pathway is well-established in BRAF mutant melanoma. Vemurafenib (Vem) was the first FDA-approved BRAF inhibitor and gained great clinical success in treating late-stage melanoma. However, most patients develop acquired resistance to Vem within 6–9 months. Therefore, developing a new treatment strategy to overcome Vem-resistance is highly significant. Our previous study reported that the combination of a tubulin inhibitor ABI-274 with Vem showed a significant synergistic effect to sensitize Vem-resistant melanoma both in vitro and in vivo. In the present study, we unveiled that VERU-111, an orally bioavailable inhibitor of α and β tubulin that is under clinical development, is highly potent against Vem-resistant melanoma cells. The combination of Vem and VERU-111 resulted in a dramatically enhanced inhibitory effect on cancer cells in vitro and Vem-resistant melanoma tumor growth in vivo compared with single-agent treatment. Further molecular signaling analyses demonstrated that in addition to ERK/AKT pathway, Skp2 E3 ligase also plays a critical role in Vem-resistant mechanisms. Knockout of Skp2 diminished oncogene AKT expression and contributed to the synergistic inhibitory effect of Vem and VERU-111. Our results indicate a treatment combination of VERU-111 and Vem holds a great promise to overcome Vem-resistance for melanoma patients harboring BRAF (V600E) mutation.


Author(s):  
Juan Du ◽  
Zhen Dong ◽  
Li Tan ◽  
Mengqin Tan ◽  
Fang Zhang ◽  
...  

Tubeimoside I (TBMS1), also referred to as tubeimoside A, is a natural compound extracted from the plant Tu Bei Mu (Bolbostemma paniculatum), which is a traditional Chinese herb used to treat multiple diseases for more than 1,000 years. Studies in recent years reported its anti-tumor activity in several cancers. However, whether it is effective in melanoma remains unknown. In the current study, we discovered that TBMS1 treatment inhibited melanoma cell proliferation in vitro and tumorigenecity in vivo. Besides, we also observed that TBMS1 treatment induced a partly disrupted autophagy, which still remained a protective role, disruption of which by chloroquine (CQ) or 3-methyladenine (3-MA) enhanced TBMS1-induced cell proliferation inhibition. CQ combined with TBMS1 even induced cellular apoptosis. BRAF(V600E) mutation and its continuously activated downstream MEK1/2-ERK1/2 cascade are found in 50% of melanomas and are important for malanomagenesis. However, hyperactivating MEK1/2-ERK1/2 cascade can also inhibit tumor growth. Intriguingly, we observed that TBMS1 rapidly hyperactivated MEK1/2-ERK1/2, inhibition of which by its inhibitor SL-327 rescued the anti-cancerous effects of TBMS1. Besides, the targets of TBMS1 were predicted by the ZINC Database based on its structure. It is revealed that protein-tyrosine phosphatase 1B (PTP1B) might be one of the targets of TBMS1. Inhibition of PTP1B by its selective inhibitor TCS401 or shRNA rescued the anti-cancerous effects of TBMS1 in melanoma cells. These results indicated that TBMS1 might activate PTP1B, which further hyperactivates MEK1/2-ERK1/2 cascade, thereby inhibiting cell proliferation in melanoma. Our results provided the potentiality of TBMS1 as a drug candidate for melanoma therapy and confirmed that rapidly hyperactivating an oncogenic signaling pathway may also be a promising strategy for cancer treatment.


2017 ◽  
Author(s):  
Robert J. Nichols ◽  
Franziska Haderk ◽  
Carlos Stahlhut ◽  
Christopher J. Schulze ◽  
Golzar Hemmati ◽  
...  

AbstractOncogenic alterations in the RAS-RAF-MEK-ERK pathway, including mutant forms of KRAS, BRAF, and loss of the tumor suppressor and RAS GTPase-activating protein (GAP) NF1, drive the growth of a wide spectrum of human cancers. While BRAF and MEK inhibitors are effective in many patients with oncogenic BRAF V600E, there are no effective targeted therapies for individuals with cancers driven by other pathway alterations, including oncogenic KRAS, non-V600E BRAF, and NF1 loss. Here, we show that targeting the PTPN11/SHP2 phosphatase with a novel small molecule allosteric inhibitor is effective against cancers bearing nucleotide-cycling oncogenic RAS (e.g. KRAS G12C), RAS-GTP dependent oncogenic BRAF (e.g. class 3 BRAF mutants), or NF1 loss in multiple preclinical models in vitro and in vivo. SHP2 inhibition suppressed the levels of RAS-GTP and phosphorylated ERK in these models and induced growth inhibition. Expression of a constitutively active mutant of the RAS guanine nucleotide exchange factor (GEF) SOS1 rescued cells from the effects of SHP2 inhibition, suggesting that SHP2 blockade decreases oncogenic RAS-RAF-MEK-ERK signaling by disrupting SOS1-mediated RAS-GTP loading. Our findings illuminate a critical function for SHP2 in promoting oncogenic RAS activation and downstream signaling in cancers with nucleotide-cycling oncogenic RAS, RAS-GTP dependent oncogenic BRAF, and NF1 loss. SHP2 inhibition thus represents a rational, biomarker-driven therapeutic strategy to be tested in patients with cancers of diverse origins bearing these oncogenic drivers and for which current treatments are largely ineffective.


2019 ◽  
Vol 21 (Supplement_6) ◽  
pp. vi57-vi57
Author(s):  
Vincent Law ◽  
Brittany Evernden ◽  
John Puskas ◽  
Gisela Caceres ◽  
Elena Ryzhova ◽  
...  

Abstract BACKGROUND Approx. 5% of melanoma pts develop LMDz. There are essentially no models of LMDz available for therapeutic development. Here we report, the in-vitro & in-vivo culturing of CSF-CTCs. METHODS CSF-CTCs were detected by the Veridex CellSearch® System. Cell-free DNA and cell-associated DNA were extracted, sequenced and profiled. Expanded ex-vivo CSF-CTCs were grown in-vitro and tested for drug sensitivity. CSF-CTCs were grown successfully in-vivo from 1 pt; labeled human Braf V600E WM164 cells were injected IT in as a control. RESULTS CSF-CTCs: 12 LMDz pts and 8 melanoma pts without LMDz were studied. All but 1 LMDz pts (92%) had CSF-CTCs (avg: 2148.6; range 23 - 3055 CTCs/ml). In contrast, 3/8 (37%) melanoma Brain Mets pts without LMDz had CSF-CTCs but fewer of them (avg: 0.31; range 0.13 - 0.6 CTCs/ml CSF). CSF-CTCs Profile: These had BrafV600E (83%), and GNAQ Q209P & NRAS Q61R in 1 pt each. Ex-vivoculture of CSF-CTCs and PDX model: After lengthy optimization of conditions we successfully expanded CSF-CTCs in vitro(~25% of pts), and in-vivo in immunodeficient mice from 1 pt (~10% of samples). Ceritinib, used as a FAK inhibitor, with MEKi was effective in-vitro (p=3.17e-6) and prolonged survival in-vivo in LMDz (median survival: >32 days vs control: 18 days; p=7.81e-5). CONCLUSIONS Though the sample size is small, this is the first report of the successful in-vitro & in-vivo culture of CSF-CTCs from pts with LMDz. Single cell analysis to determine how representative these models are and further in-vivo testing are in progress.


2019 ◽  
Vol 1 (Supplement_1) ◽  
pp. i6-i7
Author(s):  
Vincent Law ◽  
Brittany Evernden ◽  
Rajappa Kenchappa ◽  
John Puskas ◽  
Gisela Caceres ◽  
...  

Abstract BACKGROUND: Approximately 5% of melanoma pts develop LMDz. There are essentially no models of LMDz available for therapeutic development. Here we report, the in-vitro & in-vivo culturing of CSF-CTCs. METHODS: CSF-CTCs were detected by the Veridex CellSearch® System. Cell-free DNA and cell-associated DNA were extracted, sequenced and profiled. Expanded ex-vivo CSF-CTCs were grown in-vitro and tested for drug sensitivity. CSF-CTCs were grown successfully in-vivo from 1 pt; labeled human Braf V600E WM164 cells were injected IT in as a control. RESULTS: CSF-CTCs: 12 LMDz pts and 8 melanoma pts without LMDz were studied. All but 1 LMDz pts (92%) had CSF-CTCs (avg: 2148.60; range 23 - 3055 CTCs/ml). In contrast, 3/8 (37%) melanoma Brain Mets pts without LMDz had CSF-CTCs but fewer of them (avg: 0.31; range 0.13 - 0.6 CTCs/ml CSF). CSF-CTCs Profile: These had BrafV600E (83%), and GNAQ Q209P & NRAS Q61R in 1 pt each. Ex-vivo culture of CSF-CTCs and PDX model: After lengthy optimization of conditions we successfully expanded CSF-CTCs in-vitro (~25% of pts), and in-vivo in immunodeficient mice from 1 pt (~10% of samples). Ceritinib, used as a FAK inhibitor, with MEKi was effective in-vitro (p=3.17e-6) and prolonged survival in-vivo in LMDz (median survival: >32 days vs control: 18 days; p=7.81e-5). CONCLUSIONS: Though the sample size is small, this is the first report of the successful in-vitro & in-vivo culture of CSF-CTCs from pts with LMDz. Single cell analysis to determine how representative these models are and further in-vivo testing are in progress.


Blood ◽  
2017 ◽  
Vol 130 (Suppl_1) ◽  
pp. 794-794
Author(s):  
Justin Taylor ◽  
Christina Marcelus ◽  
Dean Pavlick ◽  
Ryma Benayed ◽  
Akihide Yoshimi ◽  
...  

Abstract Chromosomal rearrangements involving the neurotrophic receptor tyrosine kinases NTRK1-3 produce oncogenic fusions in a wide variety of adult and pediatric cancers. Although the frequency of NTRK fusions in most cancers is <5%, efficacy in solid tumors harboring these fusions is striking with a 76% durable response rate recently reported with the highly selective pan-TRK inhibitor larotrectinib (LOXO-101) in a cohort comprised of 17 unique tumor types. By contrast, the frequency of NTRK fusions is not well appreciated in hematologic malignancies and targeting of NTRK fusions has not been clinically tested. Herein, we describe the occurrence of NTRK fusions across >7,000 patients with hematologic malignancies and characterize their signal transduction, transforming properties, and response to larotrectinib in vitro and in an AML patient and corresponding patient-derived xenograft (PDX) in vivo . We performed targeted RNA sequencing using the Foundation One Heme sequencing panel across 7,311 cases of hematologic malignancies and discovered 8 patients (0.11%) harboring NTRK fusions. Fusions occurred in patients with histiocytic (LMNA-NTRK1, TFG-NTRK1) and dendritic cell (TPR-NTRK1) neoplasms (n=2/78), ALL (ETV6-NTRK3; n=1/659) as well as two with AML (n=2/1201). While previous case reports have reported ETV6-NTRK3 fusions in ALL and AML, our cohort also included an ETV6-NTRK2 fusion previously unreported in AML. In addition, we detected two multiple myeloma patients with NTRK3 fusions (UBE2R2-NTRK3 and HNRNPA2B1-NTRK3; n=2/1859) which represent the first description of NTRK fusions in myeloma. The fusion breakpoints are predicted to create in-frame fusions containing the tyrosine kinase domain of each of the NTRK genes and Sanger sequencing of RT-PCR on available tissues confirmed this. We next cloned 4 of these fusions and tested their transforming capacity in cytokine-dependent murine hematopoietic cells (Ba/F3 cells), which do not express endogenous Trk proteins. Despite equivalent levels of Trk expression, the transforming properties and auto-phosphorylation of each TRK fusion was distinct (A). The LMNA-NTRK1 and ETV6-NTRK2 fusions caused robust cytokine-independent growth. In contrast, additional NTRK fusions in which the 5' partner lacked classic oligomerization domains resulted in slower transformation (UBE2R2-NTRK3 fusion)or no transformation (HNRNPA2/B1-NTRK3). Consistent with these different growth properties, each fusion activated PI3K-AKT signaling to differing degrees after cytokine withdrawal (B) . Finally, the cells that gained cytokine-independence were exquisitely sensitive to treatment with larotrectinib. In contrast, Ba/F3 cells transformed by BRAF V600E mutation were unresponsive to Trk inhibition (C). The course of the above studies identified a patient with an ETV6-NTRK2 fusion AML. Using a PDX generated from this patient, we initiated treatment with larotrectinib (200mg/kg/day) after 8 weeks of transplantation when human myeloid leukemia engraftment reached a median of 15%. Larotrectinib treatment reduced human chimerism compared with mice receiving vehicle (although human myeloid leukemia cells persisted even with larotrectinib treatment- D). Consistent with the response of the AML PDX to Trk inhibition, treatment of the same patient with larotrectinib initiated under the FDA expanded access program resulted in clinical partial remission. This was due to eradication of the ETV6-NTRK2 mutant clone, which was sustained until outgrowth of a treatment refractory ETV6-MECOM clone resulted in progressive disease. FACS sorting and analysis of the AML revealed that each ETV6 fusion occurred in a distinct AML clone. Serial targeted RNA-seq analysis of bulk cells identified reduction of expression of the ETV6-NTRK2 fusion throughout the period of LOXO-101 treatment with concomitant increased expression of the ETV6-MECOM fusion (E). We herein describe that NTRK fusions occur across patients with a wide variety of hematologic malignancies and are amenable to Trk inhibition. Further studies to evaluate the clonality of NTRK fusions across cancers and whether this is predictive of therapeutic response to Trk inhibition will be critical based on the case here. Nonetheless, the clinical response here in a refractory patient argues for the need for systematic evaluation of NTRK fusions despite their rarity across hematologic neoplasms. Figure Figure. Disclosures Pavlick: Foundation Medicine: Employment. Watts: Jazz Pharmaceuticals: Consultancy, Speakers Bureau. Albacker: Foundation Medicine Inc.: Employment, Equity Ownership. Mughal: Foundation Medicine, Inc: Employment, Other: Stock. Ebata: LOXO Oncology: Employment. Tuch: LOXO Oncology: Employment. Ku: LOXO Oncology: Employment. Arcila: Archer: Honoraria; Raindance Tecnologies: Honoraria; Invivoscribe: Honoraria. Ali: Foundation Medicine, Inc: Employment, Other: Stock. Park: Amgen: Consultancy.


2021 ◽  
Vol 12 ◽  
Author(s):  
Mingjun Gao ◽  
Jin Yang ◽  
Hailong Gong ◽  
Yuancai Lin ◽  
Jing Liu

Gliomas are primary tumors originating from glial progenitor cells. Traditional treatments, including surgery, radiotherapy, and chemotherapy, have many limitations concerning the prognosis of patients with gliomas. Therefore, it is important to find novel drugs to effectively treat gliomas. Trametinib has been shown to inhibit the MAPK pathway and regulate its downstream extracellular-related kinases. It has widely been used in the treatment of BRAF V600E mutant metastatic melanomas. Previous studies found that trametinib can improve the prognosis of patients with melanoma brain metastases. In this study, we investigated the therapeutic effects of trametinib on gliomas in vivo and in vitro. We found that trametinib can inhibit proliferation, migration, and invasion of glioma cells, while inducing apoptosis of glioma cells. Specifically, trametinib can suppress both the expression of PKM2 in glioma cells and the transport of PKM2 into the cellular nucleus via suppression of ERK1/2 expression. However, inhibition of these cellular effects and intracellular glycolysis levels were reversed by overexpressing PKM2 in glioma cells. We also found inhibition of c-myc with trametinib treatment, but its expression could be increased by overexpressing PKM2. Interestingly, when PKM2 was overexpressed but c-myc silenced, we found that the initial inhibition of cellular effects and glycolysis levels by trametinib were once again restored. These inhibitory effects were also confirmed in vivo: trametinib inhibited the growth of the transplanted glioma cell tumor, whereas PKM2 overexpression and c-myc silencing restored the inhibition of trametinib on the growth of the transplanted tumor. In conclusion, these experimental results showed that trametinib may inhibit the growth and intracellular glycolysis of glioma cells by targeting the PKM2/c-myc pathway.


Cancers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2182 ◽  
Author(s):  
Nabanita Mukherjee ◽  
Carol M. Amato ◽  
Jenette Skees ◽  
Kaleb J. Todd ◽  
Karoline A. Lambert ◽  
...  

There is an urgent need to develop treatments for patients with melanoma who are refractory to or ineligible for immune checkpoint blockade, including patients who lack BRAF-V600E/K mutations. This is often the case in patients diagnosed with rare melanoma subtypes such as mucosal and acral melanoma. Here, we analyzed data from the cutaneous melanoma The Cancer Genome Atlas Network (TCGA) transcriptomic and proteomic databases for differential expression of apoptosis molecules between melanomas with or without BRAF hotspot mutations. Our data indicated higher B-cell CLL/lymphoma 2 (BCL2) expression in melanoma without BRAF hotspot mutations, suggesting that BH3 mimetics, such as ABT-199 (venetoclax, a small molecule against BCL2), may be a potential therapeutic option for these patients. We explored the efficacy of combining two BH3 mimetics, ABT-199 and a myeloid cell leukemia sequence 1 (MCL1) inhibitor (S63845 or S64315/MIK665) in cutaneous, mucosal and acral melanomas, in vitro and in vivo. Our data indicate this combination induced cell death in a broad range of melanoma cell lines, including melanoma initiating cell populations, and was more potent in melanoma cells without BRAF-V600E/K mutations. Our knockdown/knockout experiments suggest that several pro-apoptotic BCL2 family members, BCL2-like 11 (apoptosis facilitator) (BIM), phorbol-12-myristate-13-acetate-induced protein 1 (NOXA) or BID, play a role in the combination-induced effects. Overall, our study supports the rationale for combining an MCL1 inhibitor with a BCL2 inhibitor as a therapeutic option in patients with advanced melanoma.


Author(s):  
E. J. Kollar

The differentiation and maintenance of many specialized epithelial structures are dependent on the underlying connective tissue stroma and on an intact basal lamina. These requirements are especially stringent in the development and maintenance of the skin and oral mucosa. The keratinization patterns of thin or thick cornified layers as well as the appearance of specialized functional derivatives such as hair and teeth can be correlated with the specific source of stroma which supports these differentiated expressions.


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