Evaluation of Glucose Uptake in Normal and Cancer Cell Lines by Positron Emission Tomography.

To date, there is no definitive demonstration of the utility of positron emission tomography (PET) in studying glucose metabolism in cultured cell lines. Thus, this study was designed to compare PET to more standardized methods for the quantitative assessment of glucose uptake in nontransformed and transformed living cells and to validate PET for metabolic studies in vitro. Human colon and breast carcinoma cell lines and mouse embryo fibroblasts were evaluated for [ 18 F]fluorodeoxyglucose ([ 18 F]FDG) uptake by PET and autoradiography and 2-deoxyglucose (2-DG) incorporation by colorimetric assay and analyzed for the radiotoxic effects of [ 18 F]FDG and the expression levels of glucose transporters. Indeed, [ 18 F]FDG incorporation on PET was comparable to [ 18 F]FDG uptake by autoradiography and 2-DG incorporation by colorimetric assay, although radiotracer-based methods exhibited more pronounced differences between individual cell lines. As expected, these data correlated with glucose transporters 1 to 4 and hexokinase II expression in tumor cell lines and mouse fibroblasts. Notably, [ 18 F]FDG incorporation resulted in low apoptotic rates, with fibroblasts being slightly more sensitive to radiotracer-induced cell death. The quantitative analysis of [ 18 F]FDG uptake in living cells by PET represents a valuable and reproducible method to study tumor cell metabolism in vitro, being representative of the differences in the molecular profile of normal and tumor cell lines

Cyclin-dependent kinase 1 targeting improves sensitivity to radiation in BRAF V600E colorectal carcinoma cells.

Preoperative chemoradiation is currently the standard of care in locally advanced rectal carcinoma, even though a subset of rectal tumors does not achieve major clinically meaningful responses upon neoadjuvant chemoradiation. At present, no molecular biomarkers are available to predict response to neoadjuvant chemoradiation and select resistant tumors willing more intense therapeutic strategies. Thus, BRAF mutational status was investigated for its role in favoring resistance to radiation in colorectal carcinoma cell lines and cyclin-dependent kinase 1 as a target to improve radiosensitivity in BRAF V600E colorectal tumor cells.Colony-forming assay and apoptotic rates were evaluated to compare the sensitivity of different colon carcinoma cell lines to ionizing radiation and their radiosensitivity upon exposure to BRAF and/or cyclin-dependent kinase 1 inhibitory/silencing strategies. Cyclin-dependent kinase 1 expression/subcellular distribution was studied by immunoblot analysis.Colon carcinoma BRAF V600E HT29 cells exhibited poor response to radiation compared to BRAF wild-type COLO320 and HCT116 cells. Interestingly, neither radiosensitizing doses of 5-fluoruracil nor BRAF inhibition/silencing significantly improved radiosensitivity in HT29 cells. Of note, poor response to radiation correlated with upregulation/relocation of cyclin-dependent kinase 1 in mitochondria. Consistently, cyclin-dependent kinase 1 inhibition/silencing as well as its targeting, through inhibition of HSP90 quality control pathway, significantly inhibited the clonogenic ability and increased apoptotic rates in HT29 cells upon exposure to radiation.These data suggest that BRAF V600E colorectal carcinoma cells are poorly responsive to radiation, and cyclin-dependent kinase 1 represents a target to improve radiosensitivity in BRAF V600E colorectal tumor cells

RAS/BRAF mutational status in familial non‑medullary thyroid carcinomas: A retrospective study

There are contrasting views on whether familial non‑medullary thyroid carcinomas (FNMTCs) are characterized by aggressive behavior, and limited evidence exists on the prognostic value of BRAF and RAS mutations in these tumors. Thus, in the present study, clinicopathological features were analyzed in 386 non‑medullary thyroid carcinomas (NMTCs), subdivided in 82 familial and 304 sporadic cases. Furthermore, the RAS and BRAF mutational statuses were investigated in a subgroup of 34 FNMTCs to address their clinical and biological significance. The results demonstrated that, compared with sporadic NMTCs, FNMTCs are characterized by significantly higher rates of multicentricity and bilaterality and are more frequently associated with chronic autoimmune thyroiditis. Notably, a statistically significant difference in the rates of multicentricity was observed by subgrouping familial tumors according to the number of relatives involved; those with ≥3 affected relatives were more likely to be multicentric. Furthermore, the FNMTC cohort exhibited higher rates of tumors >4 cm in size with extrathyroidal or lymph node involvement. However, no significant difference was observed. Similarly, no differences were observed with respect to the age of onset or the patient outcome. The mutational profiling exhibited a rate of 58.8% for BRAF V600E mutations in familial tumors, which is at the upper limit of the mutational frequency observed in historical series of sporadic thyroid cancer. A high rate of NRAS mutations (17.6%) was also observed, mostly in the follicular variant histotype. Notably, compared with BRAF/RAS‑wild type FNMTCs, the familial carcinomas bearing BRAF or NRAS mutations exhibited slightly higher rates of bilaterality and multicentricity, in addition to increased frequency of locally advanced stage or lymph node involvement. The present data support the theory that FNMTCs are characterized by clinicopathological features that resemble a more aggressive phenotype and suggest that RAS/BRAF mutational analysis deserves to be further evaluated as a tool for the identification of FNMTCs with a potentially unfavorable prognosis

Durvalumab plus gemcitabine and cisplatin in advanced biliary tract cancer: An early exploratory analysis of real-world data

Background: The TOPAZ-1 phase III trial reported a survival benefit with the anti-programmed death cell ligand 1 (anti-PD-L1) durvalumab in combination with gemcitabine and cisplatin in patients with advanced biliary tract cancer. The present study investigated the efficacy and safety of this new standard treatment in a real-world setting.Methods: The analysed population included patients with unresectable, locally advanced or metastatic adenocarcinoma of the biliary tract treated with durvalumab in combination with gemcitabine and cisplatin at 17 Italian centres. The primary endpoint of the study was progression-free survival (PFS), whereas secondary endpoints included overall survival (OS), overall response rate (ORR) and safety. Unadjusted and adjusted hazard ratios (HRs) by baseline characteristics were calculated using the Cox proportional hazards model.Results: From February 2022 to November 2022, 145 patients were enrolled. After a median follow-up of 8.5 months (95% CI: 7.9-13.6), the median PFS was 8.9 months (95% CI: 7.4-11.7). Median OS was 12.9 months (95% CI: 10.9-12.9). The investigator-assessed confirmed ORR was 34.5%, and the disease control rate was 87.6%. Any grade adverse events (AEs) occurred in 137 patients (94.5%). Grades 3-4 AEs occurred in 51 patients (35.2%). The rate of immune-mediated AEs (imAEs) was 22.7%. Grades 3-4 imAEs occurred in 2.1% of the patients. In univariate analysis, non-viral aetiology, ECOG PS >0 and NLR >= 3 correlated with shorter PFS.Conclusion: The results reported in this first real-world analysis mostly confirmed the results achieved in the TOPAZ-1 trial in terms of PFS, ORR and safety

TRAP1 regulates stemness through Wnt/β-catenin pathway in human colorectal carcinoma

Colorectal carcinoma (CRC) is a common cause of cancer-related death worldwide. Indeed, treatment failures are triggered by cancer stem cells (CSCs) that give rise to tumor repopulation upon initial remission. Thus, the role of the heat shock protein TRAP1 in stemness was investigated in CRC cell lines and human specimens, based on its involvement in colorectal carcinogenesis, through regulation of apoptosis, protein homeostasis and bioenergetics. Strikingly, co-expression between TRAP1 and stem cell markers was observed in stem cells located at the bottom of intestinal crypts and in CSCs sorted from CRC cell lines. Noteworthy, TRAP1 knockdown reduced the expression of stem cell markers and impaired colony formation, being the CSC phenotype and the anchorage-independent growth conserved in TRAP1-rich cancer cells. Consistently, the gene expression profiling of HCT116 cells showed that TRAP1 silencing results in the loss of the stem-like signature with acquisition of a more-differentiated phenotype and the downregulation of genes encoding for activating ligands and target proteins of Wnt/β-catenin pathway. Mechanistically, TRAP1 maintenance of stemness is mediated by the regulation of Wnt/β-catenin signaling, through the modulation of the expression of frizzled receptor ligands and the control of β-catenin ubiquitination/phosphorylation. Remarkably, TRAP1 is associated with higher expression of β-catenin and several Wnt/β-catenin target genes in human CRCs, thus supporting the relevance of TRAP1 regulation of β-catenin in human pathology. This study is the first demonstration that TRAP1 regulates stemness and Wnt/β-catenin pathway in CRC and provides novel landmarks in cancer biology and therapeutics

The role of human chorionic gonadotropin as tumor marker: Biochemical and clinical aspects

Tumor markers are biological substances that are produced/released mainly by malignant tumor cells, enter the circulation in detectable amounts and are potential indicators of the presence of a tumor. The most useful biochemical markers are the tumor-specific molecules, i.e., receptors, enzymes, hormones, growth factors or biological response modifiers that are specifically produced by tumor cells and not, or minimally, by the normal counterpart (Richard et al. Principles and practice of gynecologic oncology. Wolters Kluwer Health, Philadelphia, 2009). Based on their specificity and sensitivity in each malignancy, biomarkers are used for screening, diagnosis, disease monitoring and therapeutic response assessment in clinical management of cancer patients.This chapter is focused on human chorionic gonadotropin (hCG), a hormone with a variety of functions and widely used as a tumor biomarker in selected tumors. Indeed, hCG is expressed by both trophoblastic and non-trophoblastic human malignancies and plays a role in cell transformation, angiogenesis, metastatization, and immune escape, all process central to cancer progression. Of note, hCG testing is crucial for the clinical management of placental trophoblastic malignancies and germ cell tumors of the testis and the ovary. Furthermore, the production of hCG by tumor cells is accompanied by varying degrees of release of the free subunits into the circulation, and this is relevant for the management of cancer patients (Triozzi PL, Stevens VC, Oncol Rep 6(1):7-17, 1999).The name chorionic gonadotropin was conceived: chorion derives from the latin chordate meaning afterbirth, gonadotropin indicates that the hormone is a gonadotropic molecule, acting on the ovaries and promoting steroid production (Cole LA, Int J Endocrinol Metab 9(2):335-352, 2011). The function, the mechanism of action and the interaction between hCG and its receptor continue to be the subject of intensive investigation, even though many issues about hCG have been well documented (Tegoni M et al., J Mol Biol 289(5):1375-1385, 1999)

Dual EGFR and BRAF blockade overcomes resistance to vemurafenib in BRAF mutated thyroid carcinoma cells

Abstract Background BRAF inhibitors are effective anticancer agents in BRAF-mutated melanomas. By contrast, evidences about sensitivity of thyroid carcinomas to BRAF inhibition are conflicting and it has been proposed that BRAF V600E thyroid carcinoma cells are less sensitive to BRAF inhibitors due to activation of parallel signaling pathways. This study evaluated the hypothesis that feedback activation of EGFR signaling counteracts the cytostatic activity of vemurafenib (PLX4032) in BRAF V600E thyroid carcinoma cells. Methods Cell proliferation, cell cycle distribution, induction of apoptosis and EGFR and AKT signaling were evaluated in thyroid carcinoma cell lines bearing the BRAF V600E mutation in response to PLX4032. Results A partial and transient cytostatic response to PLX4032 was observed in thyroid carcinoma cell lines bearing the BRAF V600E mutation, with lack of full inhibition of ERK pathway. Interestingly, the exposure of thyroid carcinoma cells to PLX4032 resulted in a rapid feedback activation of EGFR signaling with parallel activation of AKT phosphorylation. Consistently, the dual inhibition of EGFR and BRAF, through combination therapy with PLX4032 and gefitinib, resulted in prevention of EGFR phosphorylation and sustained inhibition of ERK and AKT signaling and cell proliferation. Of note, the combined treatment with gefitinib and vemurafenib or the exposure of EGFR-silenced thyroid carcinoma cells to vemurafenib induced synthetic lethality compared to single agents. Conclusions These data suggest that the dual EGFR and BRAF blockade represents a strategy to by-pass resistance to BRAF inhibitors in thyroid carcinoma cells

ER stress protection in cancer cells: the multifaceted role of the heat shock protein TRAP1

TRAP1 is an HSP90 chaperone, upregulated in human cancers and involved in organelles’ homeostasis and tumor cell metabolism. Indeed, TRAP1 is a key regulator of adaptive responses used by highly proliferative tumors to face the metabolic stress induced by increased demand of protein synthesis and hostile environments. Besides well-characterized roles in prevention of mitochondrial permeability transition pore opening and in regulating mitochondrial respiration, TRAP1 is involved in novel regulatory mechanisms: i) the attenuation of global protein synthesis, ii) the co-translational regulation of protein synthesis and ubiquitination of specific client proteins, and iii) the protection from Endoplasmic Reticulum stress. This provides a crucial role to TRAP1 in maintaining cellular homeostasis through protein quality control, by avoiding the accumulation of damaged or misfolded proteins and, likely, facilitating the synthesis of selective cancer-related proteins. Herein, we summarize how these regulatory mechanisms are part of an integrated network, which enables cancer cells to modulate their metabolism and to face, at the same time, oxidative and metabolic stress, oxygen and nutrient deprivation, increased demand of energy production and macromolecule biosynthesis. The possibility to undertake a new strategy to disrupt such networks of integrated control in cancer cells holds great promise for treatment of human malignancies