Browsing by Subject "ACQUIRED-RESISTANCE"

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  • Cervera-Carrascon, Victor; Quixabeira, Dafne C. A.; Santos, Joao M.; Havunen, Riikka; Milenova, Ioanna; Verhoeff, Jan; Heinio, Camilla; Zafar, Sadia; Garcia-Vallejo, Juan J.; van Beusechem, Victor W.; de Gruijl, Tanja D.; Kalervo, Aino; Sorsa, Suvi; Kanerva, Anna; Hemminki, Akseli (2021)
    Immune checkpoint inhibitors such as anti-PD-1 have revolutionized the field of oncology over the past decade. Nevertheless, the majority of patients do not benefit from them. Virotherapy is a flexible tool that can be used to stimulate and/or recruit different immune populations. T-cell enabling virotherapy could enhance the efficacy of immune checkpoint inhibitors, even in tumors resistant to these inhibitors. The T-cell potentiating virotherapy used here consisted of adenoviruses engineered to express tumor necrosis factor alpha and interleukin-2 in the tumor microenvironment. To study virus efficacy in checkpoint-inhibitor resistant tumors, we developed an anti-PD-1 resistant melanoma model in vivo. In resistant tumors, adding virotherapy to an anti-PD-1 regimen resulted in increased survival (p=0.0009), when compared to anti-PD-1 monotherapy. Some of the animals receiving virotherapy displayed complete responses, which did not occur in the immune checkpoint-inhibitor monotherapy group. When adenoviruses were delivered into resistant tumors, there were signs of increased CD8 T-cell infiltration and activation, which - together with a reduced presence of M2 macrophages and myeloid-derived suppressor cells - could explain those results. T-cell enabling virotherapy appeared as a valuable tool to counter resistance to immune checkpoint inhibitors. The clinical translation of this approach could increase the number of cancer patients benefiting from immunotherapies.
  • Aly, Ashraf A.; El-Sheref, Essmat M.; Bakheet, Momtaz E. M.; Mourad, Mai A. E.; Bräse, Stefan; Ibrahim, Mahmoud A. A.; Nieger, Martin; Garvalov, Boyan K.; Dalby, Kevin N.; Kaoud, Tamer S. (2019)
    Approximately 60% of human cancers exhibit enhanced activity of ERK1 and ERK2, reflecting their multiple roles in tumor initiation and progression. Acquired drug resistance, especially mechanisms associated with the reactivation of the MAPK (RAF/MEK/ERK) pathway represent a major challenge to current treatments of melanoma and several other cancers. Recently, targeting ERK has evolved as a potentially attractive strategy to overcome this resistance. Herein, we report the design and synthesis of novel series of fused naphthofuro[3,2-c] quinoline-6,7,12-triones 3a-f and pyrano[3,2-c]quinoline-6,7,8,13-tetraones 5a,b and 6, as potential ERK inhibitors. New inhibitors were synthesized and identified by different spectroscopic techniques and X-ray crystallography. They were evaluated for their ability to inhibit ERK1/2 in an in vitro radioactive kinase assay. 3b and 6 inhibited ERK1 with IC50s of 0.5 and 0.19 mu M, and inhibited ERK2 with IC50s of 0.6 and 0.16 mu M respectively. Kinetic mechanism studies revealed that the inhibitors are ATP-competitive inhibitors where 6 inhibited ERK2 with a K-i of 0.09 mu M. Six of the new inhibitors were tested for their in vitro anticancer activity against the NCI-60 panel of tumor cell lines. Compound 3b and 6 were the most potent against most of the human tumor cell lines tested. Moreover, 3b and 6 inhibited the proliferation of the BRAF mutant A375 melanoma cells with IC50s of 3.7 and 0.13 mu M, respectively. In addition, they suppressed anchorage-dependent colony formation. Treatment of the A375 cell line with 3b and 6 inhibited the phosphorylation of ERK substrates p-90RSK and ELK-1 and induced apoptosis in a dose dependent manner. Finally, a molecular docking study showed the potential binding mode of 3b and 6 within the ATP catalytic binding site of ERK2.
  • Birkman, Eva-Maria; Avoranta, Tuulia; Algars, Annika; Korkeila, Eija; Lintunen, Minnamaija; Lahtinen, Laura; Kuopio, Teijo; Ristamäki, Raija; Carpen, Olli; Sundström, Jari (2018)
    Epidermal growth factor receptor (EGFR) gene copy number (GCN) increase is associated with a favorable anti-EGFR antibody treatment response in RAS wild-type metastatic colorectal cancer. However, there are limited and comparative data regarding the EGFR GCN in primary colorectal cancer tumors and corresponding metastases or the effect of anti-EGFR antibody treatment on EGFR GCN in recurrent disease. In addition, little is known about the potential EGFR GCN changes during anti-EGFR therapy in comparison with other treatment regimens. EGFR GCN was analyzed by EGFR immunohistochemistry-guided silver in situ hybridization in primary and corresponding recurrent local or metastatic tumors from 80 colorectal cancer patients. GCN levels were compared between KRAS wild-type patients having received antiEGFR therapy and patients having received other forms of treatment after primary surgery. The EGFR GCN decrease between primary and recurrent tumors was more pronounced among the anti EGFR-treated patients than among patients not treated with anti-EGFR therapy (P=.047). None of the patients experiencing an EGFR GCN increase of at least 1.0 between the primary and recurrent tumors were treated with antiEGFR antibodies. When including only patients with distant metastases, an EGFR GCN decrease of at least 1.0 was more common among the anti EGFR-treated patients than among patients not treated with anti-EGFR therapy (P=.028). Our results suggest that anti-EGFR antibody treatment is associated with EGFR GCN decrease between the primary and recurrent colorectal adenocarcinomas, whereas no GCN change is observed among patients receiving other forms of treatment after primary surgery. (C) 2018 The Authors. Published by Elsevier Inc.
  • Hanker, Ariella B.; Garrett, Joan T.; Estrada, Monica Valeria; Moore, Preston D.; Ericsson, Paula Gonzalez; Koch, James P.; Langley, Emma; Singh, Sharat; Kim, Phillip S.; Frampton, Garrett M.; Sanford, Eric; Owens, Philip; Becker, Jennifer; Groseclose, M. Reid; Castellino, Stephen; Joensuu, Heikki; Huober, Jens; Brase, Jan C.; Majjaj, Samira; Brohee, Sylvain; Venet, David; Brown, David; Baselga, Jose; Piccart, Martine; Sotiriou, Christos; Arteaga, Carlos L. (2017)
    Purpose: Dual blockade of HER2 with trastuzumab and lapatinib or pertuzumab has been shown to be superior to single-agent trastuzumab. However, a significant fraction of HER2-overexpressing (HER2(+)) breast cancers escape from these drug combinations. In this study, we sought to discover the mechanisms of acquired resistance to the combination of lapatinib + trastuzumab. Experimental Design: HER2(+) BT474 xenografts were treated with lapatinib + trastuzumab long-term until resistance developed. Potential mechanisms of acquired resistance were evaluated in lapatinib + trastuzumab-resistant (LTR) tumors by targeted capture next-generation sequencing. In vitro experiments were performed to corroborate these findings, and a novel drug combination was tested against LTR xenografts. Gene expression and copy-number analyses were performed to corroborate our findings in clinical samples. Results: LTR tumors exhibited an increase in FGF3/4/19 copy number, together with an increase in FGFR phosphorylation, marked stromal changes in the tumor microenvironment, and reduced tumor uptake of lapatinib. Stimulation of BT474 cells with FGF4 promoted resistance to lapatinib + trastuzumab in vitro. Treatment with FGFR tyrosine kinase inhibitors reversed these changes and overcame resistance to lapatinib + trastuzumab. High expression of FGFR1 correlated with a statistically shorter progression-free survival in patients with HER2(+) early breast cancer treated with adjuvant trastuzumab. Finally, FGFR1 and/or FGF3 gene amplification correlated with a lower pathologic complete response in patients with HER2(+) early breast cancer treated with neoadjuvant anti-HER2 therapy. Conclusions: Amplification of FGFR signaling promotes resistance to HER2 inhibition, which can be diminished by the combination of HER2 and FGFR inhibitors. (C) 2017 AACR.