Platinum-Triggered Bond-Cleavage of Pentynoyl Amide and N-Propargyl Handles for Drug-Activation.

The ability to create ways to control drug activation at specific tissues while sparing healthy tissues remains a major challenge. The administration of exogenous target-specific triggers offers the potential for traceless release of active drugs on tumor sites from antibody-drug conjugates (ADCs) and caged prodrugs. We have developed a metal-mediated bond-cleavage reaction that uses platinum complexes [K2PtCl4 or Cisplatin (CisPt)] for drug activation. Key to the success of the reaction is a water-promoted activation process that triggers the reactivity of the platinum complexes. Under these conditions, the decaging of pentynoyl tertiary amides and N-propargyls occurs rapidly in aqueous systems. In cells, the protected analogues of cytotoxic drugs 5-fluorouracil (5-FU) and monomethyl auristatin E (MMAE) are partially activated by nontoxic amounts of platinum salts. Additionally, a noninternalizing ADC built with a pentynoyl traceless linker that features a tertiary amide protected MMAE was also decaged in the presence of platinum salts for extracellular drug release in cancer cells. Finally, CisPt-mediated prodrug activation of a propargyl derivative of 5-FU was shown in a colorectal zebrafish xenograft model that led to significant reductions in tumor size. Overall, our results reveal a new metal-based cleavable reaction that expands the application of platinum complexes beyond those in catalysis and cancer therapy.EPSRC studentship for Benjamin Stenton

Predictive and therapeutic implications of a novel PLCγ1/SHP2-driven mechanism of cetuximab resistance in metastatic colorectal cancer

© 2022 The Authors; Published by the American Association for Cancer Research. This open access article is distributed under Creative Commons Attribution-NonCommercial-NoDerivatives License 4.0 International (CC BY-NC-ND)Purpose: Cetuximab is an EGFR-targeted therapy approved for the treatment of RAS wild-type (WT) metastatic colorectal cancer (mCRC). However, about 60% of these patients show innate resistance to cetuximab. To increase cetuximab efficacy, it is crucial to successfully identify responder patients, as well as to develop new therapeutic approaches to overcome cetuximab resistance. Experimental design: We evaluated the value of EGFR effector phospholipase C gamma 1 (PLCγ1) in predicting cetuximab responses, by analyzing progression-free survival (PFS) of a multicentric retrospective cohort of 94 treated patients with mCRC (log-rank test and Cox regression model). Furthermore, we used in vitro and zebrafish xenotransplant models to identify and target the mechanism behind PLCγ1-mediated resistance to cetuximab. Results: In this study, levels of PLCγ1 were found increased in RAS WT tumors and were able to predict cetuximab responses in clinical samples and in vitro and in vivo models. Mechanistically, PLCγ1 expression was found to bypass cetuximab-dependent EGFR inhibition by activating ERK and AKT pathways. This novel resistance mechanism involves a noncatalytic role of PLCγ1 SH2 tandem domains in the propagation of downstream signaling via SH2-containing protein tyrosine phosphatase 2 (SHP2). Accordingly, SHP2 inhibition sensitizes PLCγ1-resistant cells to cetuximab. Conclusions: Our discoveries reveal the potential of PLCγ1 as a predictive biomarker for cetuximab responses and suggest an alternative therapeutic approach to circumvent PLCγ1-mediated resistance to cetuximab in patients with RAS WT mCRC. In this way, this work contributes to the development of novel strategies in the medical management and treatment of patients with mCRC.M. Martins' research was supported by Liga Portuguesa Contra o Cancro (LPCC): Terry Fox Fundation; Investigador FCT- Fundação para a Ciência e Technologia (IF/00409/2014) and IMM Bridge grant; RC-D research was supported by Fundação para a Ciência e Technologia (SFRH/BD/139138/2018). A. Fernandes was supported by LPCC-IMM BIOBANK; R. Fior was supported by Champalimaud Foundation and L. Costa was supported by Merck Serono.info:eu-repo/semantics/publishedVersio

Impacto da doença oncológica na estimulação ovárica para preservação da fertilidade.

Trabalho Final do Mestrado Integrado em Medicina apresentado à Faculdade de MedicinaWith the improvement of diagnostic and treatment techniques in oncology, there has been a significant increase in the survival rates of women of childbearing age with cancer diagnoses, and consequently in women undergoing controlled ovarian stimulation (COS) for fertility preservation (FP). However, the impact of cancer on COS is controversial and studies in this area have produced conflicting results. Thus, the aim of this study was to investigate the impact of cancer prior to gonadotoxic treatments on ovarian reserve and ovarian response to COS.A retrospective study was conducted using an anonymous database of patients who underwent COS for FP excluding women who had already undergone potentially gonadotoxic treatment. The patients were categorized into cancer and non-cancer group and subcategorized based on cancer type: breast, ovarian, hematologic, colorectal and others. Some clinical differences were found between groups, such as in age, parity and in patients’ smoking habits. Breast and colorectal cancer patients were older than those without a cancer diagnosis (p=0.000 and p=0.001, respectively) and with hematological cancer (p=0.000 and p=0.023, respectively), and also had lower nulliparity rates compared to non-cancer group (p=0.027). There was a higher percentage of women without a cancer diagnosis with smoking habits compared to those with breast and hematological cancers (p=0.003 and p=0.013, respectively). Ovarian reserve and response to stimulation were similar in the two groups. However, a tendency to lower ovarian reserve was observed in women with colorectal cancer, namely anti-Müllerian hormone (AMH) levels were about half compared to the other groups. In this group, there was also a tendency for poorer response to ovarian stimulation, with fewer oocytes available for cryopreservation, and a higher percentage of women in whom no oocyte preservation was possible.In conclusion, there were no differences in ovarian reserve and response to COS according to cancer type, except for a negative trend in colorectal cancer patients. Additionally, reproductive counseling for cancer patients should consider other factors that can impact fertility, such as age and smoking habits. This knowledge enables us to improve reproductive counseling in this population.A preservação da fertilidade (PF) emergiu como oportunidade de assegurar o futuro reprodutivo dos doentes oncológicos, pelo impacto negativo dos tratamentos na fertilidade em paralelo com o aumento da sobrevivência e o adiamento da maternidade. O impacto da doença oncológica na reserva ovárica e na resposta à estimulação ovárica (EO) para criopreservação de ovócitos é controverso e a evidência científica existente nesta área é escassa.O objetivo do trabalho foi investigar o efeito do cancro na reserva ovárica e na resposta à EO.Realizou-se um estudo retrospetivo após análise dos dados clínicos de doentes que realizaram criopreservação de ovócitos para PF, nos últimos 10 anos. Foram constituídos dois grupos principais mediante a existência de doença oncológica e subgrupos de acordo com o tipo de cancro. Foram incluídas 196 mulheres, das quais 39 encaminhadas por motivos não oncológicos, como transgénero e síndrome do X-frágil. As restantes 157 mulheres apresentavam uma indicação oncológica para PF, das quais 106 tinham cancro da mama, 31 cancro hematológico, 9 cancro do ovário, 7 cancro colorretal e 4 outros tipos de cancro.As mulheres com diagnóstico de cancro da mama e cancro colorretal são significativamente mais velhas do que as sem diagnóstico oncológico (p=0,000 e p=0,001, respetivamente) e do que as com cancro hematológico (p=0,000 e p=0,023, respetivamente). Verificaram-se diferenças na paridade (p=0,027), com menor percentagem de nuliparidade nas mulheres com cancro da mama e cancro colorretal. Relativamente ao tabagismo também se verificaram diferenças (p=0,015), com maior percentagem nas mulheres sem diagnóstico oncológico comparativamente com as com cancro da mama e cancro hematológico (p=0,003 e p= 0,013, respetivamente). Para as restantes características clínicas e para o estadiamento oncológico não se observaram diferenças entre grupos.Na análise da reserva ovárica não foram observadas diferenças nos níveis de hormona anti-Mülleriana (HAM) entre grupos. O mesmo foi verificado para resposta à EO, no que diz respeito ao número total de ovócitos preservados e número de ovócitos maduros. No entanto, as mulheres com cancro colorretal apresentaram tendencialmente menor reserva ovárica, com níveis de HAM de cerca de metade comparativamente com os restantes grupos. Neste grupo verificou-se ainda uma tendência para pior resposta à EO com menor número total de ovócitos preservados, menos ovócitos maduros e maior percentagem de mulheres nas quais não foi possível preservar nenhum ovócito.Em conclusão, não se verificaram diferenças na reserva ovárica e resposta à EO de acordo com o tipo de cancro, exceto uma tendência negativa para o cancro colorretal. Adicionalmente há outros fatores, como a idade e os hábitos tabágicos, que podem influenciar o impacto na fertilidade. Este conhecimento permite melhorar o aconselhamento reprodutivo nesta população

Cisplatin-Triggered Bioorthogonal Decaging of Amide Bonds for Targeted-Drug Activation in vivo

Creating ways to control drug activation at specific tissues while sparing healthy tissues remains a major challenge. The administration of exogenous triggers offers the possibility for precise and traceless drug activation. However, ensuring localization of the trigger as well as the prodrug at the diseased tissue is complex while essential for therapeutic efficacy and to avoid side-toxicity. Cisplatin remains a first line option to treat 20% of all cancer patients and while clearing after 30 min from blood it concentrates in tumor tissues. Here, we demonstrate the use of the platinum-mediated bond cleavage of protected tertiary amides, which can occur in a catalytic manner under bioorthogonal conditions. Protected analogues of cytotoxic drugs 5-fluorouracil (5-FU) and monomethyl auristatin E (MMAE) were successfully activated using non-toxic amounts of platinum salts in cells. An otherwise fully stable and non-internalizing ADC built using a bifunctional linker featuring a tertiary amide protected MMAE was also bioorthogonally decaged in the presence of platinum salts for extracellular drug release. Finally, cisplatin-mediated activation of a prodrug 5-FU was shown in a colorectal zebrafish xenograft model leading to a significant tumor reduction. Considering cisplatin’s continued use as a first-choice treatment for many solid cancers and especially in colorectal cancer, we anticipate that our platinum-mediated decaging strategy will enhance cancer therapy by allowing tumor specific prodrug activation.</p

The histone acetyltransferase hMOF promotes vascular invasion in hepatocellular carcinoma

International audienceBACKGROUND & AIMS:Vascular invasion is a major prognostic factor in hepatocellular carcinoma (HCC). We previously identified histone H4 acetylated at lysine 16 (H4K16ac), a histone modification involved in transcription activation, as a biomarker of microvascular invasion (mVI) in HCC. This study aimed to investigate the role of hMOF, the histone acetyltransferase responsible for H4K16 acetylation, in the process of vascular invasion in HCC.METHODS:hMOF expression was assessed by RT-qPCR and immunohistochemistry in a retrospective series of HCC surgical samples, and correlated with the presence of mVI. The functional role of hMOF in HCC vascular invasion was investigated in vitro in HCC cell lines using siRNA, transcriptomic analysis and transwell invasion assay, and in vivo using a Zebrafish embryo xenograft model.RESULTS:We found that hMOF was significantly upregulated at the protein level in HCC with mVI, compared with HCC without mVI (P < .01). Transcriptomic analysis showed that hMOF downregulation in HCC cell line lead to significant downregulation of key genes and pathways involved in vascular invasion. These results were confirmed by transwell invasion assay, where hMOF downregulation significantly reduced HCC cells invasion. Finally, hMOF downregulation significantly reduced tumour cell intravasation and metastasis in vivo.CONCLUSIONS:Altogether, these results underpin a critical role for hMOF in vascular invasion in HCC, via transcription activation of key genes involved in this process. These data confirm the major role of epigenetic alterations in HCC progression, and pave the way for future therapies targeting hMOF in HCC