Publications by authors named "Valeri N"

Purpose: we tested whether ctDNA changes may be used to assess early response and clinical outcome in metastatic colorectal cancer (mCRC) patients undergoing front-line systemic anti-cancer therapy (SACT).

Experimental Design: 862 plasma samples were collected 4-weekly from baseline (BL) until disease progression in mCRC patients receiving front line SACT. ctDNA normalization was defined as ≥99% clearance after 1 month of therapy (Mo1) in the 3 variants with the highest allele frequency in BL ctDNA.

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Purpose: The multi-kinase inhibitor (mKi) regorafenib has demonstrated efficacy in chemorefractory patients with metastatic colorectal cancer (mCRC). However, lack of predictive biomarkers and concerns over significant toxicities hamper the use of regorafenib in clinical practice.

Experimental Design: Serial liquid biopsies were obtained at baseline and monthly until disease progression in chemorefractory patients with mCRC treated with regorafenib in a phase II clinical trial (PROSPECT-R n = 40; NCT03010722) and in a multicentric validation cohort (n = 241).

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Article Synopsis
  • Mismatch repair (MMR) immunohistochemical evaluation is now a routine method for identifying colorectal cancer (CRC) patients with MMR deficiency, which is important for personalized treatment.
  • In a study analyzing 8282 CRCs for MMR proteins, 12.8% were found to have altered MMR status, with a small fraction (0.56%) exhibiting intratumor heterogeneity.
  • The authors emphasize the need for careful consideration of MMR heterogeneity in clinical settings, as it can affect the accuracy of diagnoses and patient care.
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Background: This study aimed to identify microRNAs (miRs) as circulating biomarkers of resistance to first-line trastuzumab-based therapy in advanced HER2-positive oesophago-gastric cancer patients.

Methods: A high-throughput 1015 Exiqon miRCURY LNA™ microRNA inhibitor library screen was performed in trastuzumab-treated HER2-positive NCI-N87 and HER2-negative FLO-1 oesophago-gastric cancer cell lines. NanoString nCounter miR analysis was performed in NCI-N87, FLO-1, and MAGIC trial (ISRCTN93793971) formalin-fixed paraffin-embedded (FFPE) oesophago-gastric cancer patient samples.

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  • Genomics is transforming cancer treatment, but solid, clinical-grade genomic biomarkers for chemotherapy are still needed.
  • A study with 37 patients found KRAS mutations linked to resistance against the chemotherapy trifluridine/tipiracil (FTD/TPI), and a larger real-world analysis with 960 patients confirmed that these mutations correspond to lower survival rates.
  • Data from a phase 3 trial with 800 patients showed that those with KRAS mutations did not benefit from FTD/TPI, indicating that identifying these mutations could guide treatment decisions for around 28% of metastatic colorectal cancer patients.
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Adenomatous polyposis coli (APC) mutation is the hallmark of colorectal cancer (CRC), resulting in constitutive WNT activation. Despite decades of research, targeting WNT signaling in cancer remains challenging due to its on-target toxicity. We have previously shown that the deubiquitinating enzyme USP7 is a tumor-specific WNT activator in APC-truncated cells by deubiquitinating and stabilizing β-catenin, but its role in gut tumorigenesis is unknown.

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Papillary thyroid carcinoma (PTC) is a miscellaneous disease with a variety of histological variants, each with its own mutational profile, and clinical and prognostic characteristics. Identification of microRNA (miRNA) expression profiles represents an important benchmark for understanding the molecular mechanisms underlying the biological behavior of these unique PTC subtypes in order that they be better characterized. We considered a series of 35 PTC samples with a histological diagnosis of either hobnail (17 cases) or classical variant (nine cases) and with a specific p.

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Background: Diffusion weighted imaging (DWI) with intravoxel incoherent motion (IVIM) modelling can inform on tissue perfusion without exogenous contrast administration. Dynamic-contrast-enhanced (DCE) MRI can also characterise tissue perfusion, but requires a bolus injection of a Gadolinium-based contrast agent. This study compares the use of DCE-MRI and IVIM-DWI methods in assessing response to anti-angiogenic treatment in patients with colorectal liver metastases in a cohort with confirmed treatment response.

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FOLFIRINOX, a combination of chemotherapy drugs (Fluorouracil, Oxaliplatin, Irinotecan -FOI), provides the best clinical benefit in pancreatic ductal adenocarcinoma (PDAC) patients. In this study we explore the role of miRNAs (MIR) as modulators of chemosensitivity to identify potential biomarkers of response. We find that 41 and 84 microRNA inhibitors enhance the sensitivity of Capan1 and MiaPaCa2 PDAC cells respectively.

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Purpose: We hypothesised that plasticity in signal transduction may be a mechanism of drug resistance and tested this hypothesis in the setting of cetuximab resistance in patients with KRAS/NRAS/BRAF wild-type colorectal cancer (CRC).

Methods: A multiplex antibody-based platform was used to study simultaneous changes in signal transduction of 55 phospho-proteins in 12 KRAS/NRAS/BRAF wild-type CRC cell lines (6 cetuximab sensitive versus 6 cetuximab resistant) following 1 and 4 h in vitro cetuximab exposure. We validated our results in CRC patient samples (n = 4) using ex vivo exposure to cetuximab in KRAS/NRAS/BRAF cells that were immunomagnetically separated from the serous effusions of patients with known cetuximab resistance.

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Background: Intratumor heterogeneity (ITH) is described as the presence of various clones within one tumor, each with their own unique features in terms of morphology, inflammation, genetics or transcriptomics. Heterogeneity provides the fuel for drug resistance; therefore, an accurate assessment of tumor heterogeneity is essential for the development of effective therapies. The purpose of this study was to dissect morphologic and molecular ITH in colorectal adenocarcinoma.

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Junctional adhesion molecules (JAMs) play a critical role in cell permeability, polarity and migration. JAM-A, a key protein of the JAM family, is altered in a number of conditions including cancer; however, consequences of JAM-A dysregulation on carcinogenesis appear to be tissue dependent and organ dependent with significant implications for the use of JAM-A as a biomarker or therapeutic target. Here, we test the expression and prognostic role of JAM-A downregulation in primary and metastatic colorectal cancer (CRC) (n = 947).

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Oesophageal cancer is one of the most aggressive malignancies with limited treatment options, thus resulting in a high morbidity and mortality. With 5‑year survival rates of only 5‑10%, oesophageal cancer holds a dismal prognosis for patients. In order to improve overall survival, the early diagnosis and tools for patient stratification for personalized treatment are urgent needs.

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Gastroesophageal adenocarcinomas (GEA) remain difficult to treat with limited targeted therapeutics. Negative results from randomized trials of EGFR inhibitors (EGFRi) in patients with molecularly unselected GEA have hampered the development of EGFRi in the gastroesophageal cancer space. A recent study reopens the game.

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Article Synopsis
  • Many tumor cells rely on external sources of serine, and cutting off serine and glycine from the diet can slow down cancer growth and improve survival in mice.
  • Even though this treatment is promising, some tumors develop resistance through mechanisms like increasing their own serine production.
  • The study shows that blocking PHGDH, an enzyme in serine synthesis, alongside a serine-deficient diet, can effectively inhibit cancer and improve treatment outcomes, even in tumors that typically resist such strategies.
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Pancreatic cancer is one of the most aggressive malignancies with limited treatment options thus resulting in high morbidity and mortality. Among all cancers, with a five-year survival rates of only 2-9%, pancreatic cancer holds the worst prognostic outcome for patients. To improve the overall survival, an earlier diagnosis and stratification of cancer patients for personalized treatment options are urgent needs.

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  • Research using mouse models and organoids shows that the KRAS G12D mutation alters translation processes, leading to increased c-MYC protein expression through the MNK/eIF4E pathway.
  • Targeting this pathway can make KRAS mutant cancers more responsive to rapamycin and is linked to poor patient survival, indicating a potential treatment strategy for a specific patient group.
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Objective: Epidermal growth factor receptor (EGFR) inhibition may be effective in biomarker-selected populations of advanced gastro-oesophageal adenocarcinoma (aGEA) patients. Here, we tested the association between outcome and copy number (CN) in pretreatment tissue and plasma cell-free DNA (cfDNA) of patients enrolled in a randomised first-line phase III clinical trial of chemotherapy or chemotherapy plus the anti-EGFR monoclonal antibody panitumumab in aGEA (NCT00824785).

Design: CN by either fluorescence in situ hybridisation (n=114) or digital-droplet PCR in tissues (n=250) and plasma cfDNAs (n=354) was available for 474 (86%) patients in the intention-to-treat (ITT) population.

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Non-coding RNAs are important regulators of differentiation during embryogenesis as well as key players in the fine-tuning of transcription and furthermore, they control the post-transcriptional regulation of mRNAs under physiological conditions. Deregulated expression of non-coding RNAs is often identified as one major contribution in a number of pathological conditions. Non-coding RNAs are a heterogenous group of RNAs and they represent the majority of nuclear transcripts in eukaryotes.

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Background: Image-guided tissue biopsies are critically important in the diagnosis and management of cancer patients. High-yield samples are also vital for biomarker and resistance mechanism discovery through molecular/genomic analyses.

Patients And Methods: All consecutive patients who underwent plugged image-guided biopsy at Royal Marsden from June 2013 until September 2016 were included in the analysis.

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MicroRNAs are small RNA transcripts involved in fine-tuning of several cellular mechanisms and pathways crucial for maintaining cells' homeostasis like apoptosis, differentiation, inflammation and cell-cycle regulation. They act by regulation of gene expression at post-transcriptional level through fine-tuning of target proteins expression. Expression of microRNAs is cell-type specific and since their discovery they have been proven to be deregulated in various disorders including cancer.

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The COVID-19 pandemic has inevitably caused those involved in cancer care to change clinical practice in order to minimize the risk of infection while maintaining cancer treatment as a priority. General advice during the pandemic suggests that most patients continue with ongoing therapies or planned surgeries, while follow-up visits may instead be delayed until the resolution of the outbreak. We conducted a literature search using PubMed to identify articles published in English language that reported on care recommendations for cancer patients during the COVID-19 pandemic from its inception up to 1st June 2020, using the terms "(cancer or tumor) AND (COVID 19)".

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