Perspective on the Role of Gut Microbiome in the Treatment of Hepatocellular Carcinoma with Immune Checkpoint Inhibitors.

Background and Objectives: Hepatocellular carcinoma (HCC) is the leading cause of liver cancer worldwide and has a high mortality rate. Its incidence has increased due to metabolic-associated liver disease (MAFLD) epidemics. Liver transplantation and surgery remain the most resolute measures. Despite the optimistic use of multi-kinase inhibitors, namely sorafenib, the co-existence of chronic liver disease made the response rate low in these patients. Immune checkpoint inhibitors (ICIs) have become a promising hope for certain advanced solid tumors and, also, for advanced HCC. Unfortunately, a large cohort of patients with HCC fail to respond to immunotherapy. Materials and Methods: We conducted a narrative search on the main medical databases for original articles, reviews, meta-analyses, randomized clinical trials, and case series using the following keywords and acronyms and their associations: hepatocellular carcinoma, immunotherapy, checkpoint inhibitors, gut microbiota, and fecal microbiota transplantation. Results: ICIs are a promising and sufficiently safe treatment option for HCC. In detail, they have significantly improved survival and prognosis in these patients vs. sorafenib. Although there are several highlighted mechanisms of resistance, the gut microbiota signature can be used both as a response biomarker and as an effect enhancer. Practically, probiotic dose-finding and fecal microbiota transplantation are the weapons that can be used to increase ICI's treatment-response-reducing resistance mechanisms. Conclusion: Immunotherapy has been a significant step-up in HCC treatment, and gut microbiota modulation is an effective liaison to increase its efficacy.

Impact of Signet-Ring Cell Histology in the Management of Patients with Non-Metastatic Gastric Cancer: Results from a Retrospective Multicenter Analysis Comparing FLOT Perioperative Chemotherapy vs. Surgery Followed by Adjuvant Chemotherapy.

BACKGROUND: FLOT perioperative chemotherapy represents the standard of care in non-metastatic gastric cancer patients. Signet-ring cell positivity is associated with a worse prognosis in patients with gastric cancer treated with chemotherapy. Comparison between FLOT perioperative chemotherapy vs. surgery followed by adjuvant chemotherapy based on signet-ring cell positivity is lacking. The aim of the analysis was to compare perioperative FLOT with adjuvant chemotherapy in gastric cancer patients stratified by signet-ring cell positivity. METHODS: We conducted a retrospective multicenter analysis based on disease-free survival (DFS) and overall survival (OS) in patients with gastric cancer who received perioperative chemotherapy with a FLOT regimen and compared their survival with a historical cohort of patients treated with adjuvant chemotherapy, matched by cT and cN stage and by tumor histological features. RESULTS: Seventy-six patients were enrolled and 24 (32%) were signet-ring cell positive. At a median follow-up time of 39 months, the median DFS was 26.3 months and the median OS was 37.3 months. Signet-ring cell positivity was associated with a shorter OS (median OS: 20.4 vs. 46.9 months, HR: 3.30, 95%CI: 1.56-6.99, p = 0.0018) and DFS (mDFS: 15.2 vs. 38.6 months, HR: 3.18, 95%CI: 1.55-6.54, p = 0.0016). This was confirmed by multivariate analysis for DFS (Exp(B): 2.55) and OS (Exp(B): 2.68). After propensity score matching, statistically significant shorter DFS (HR: 3.30, 95%CI: 1.50-7.35, p = 0.003) and OS (HR: 5.25, 95%CI: 2.18-12-68, p = 0.0002) were observed for patients with signet-ring cell positivity who received perioperative treatment vs. those who received surgery followed by adjuvant chemotherapy. CONCLUSIONS: Signet-ring positivity was associated with shorter DFS and OS in patients who received perioperative treatment with FLOT compared with surgery followed by adjuvant therapy. These data suggest that for patients with signet-ring cell histology, FLOT perioperative treatment might not always be the best choice of treatment, and further research should be focused on this group of patients.

Type 2 Diabetes Mellitus and Efficacy Outcomes from Immune Checkpoint Blockade in Patients with Cancer.

PURPOSE: No evidence exists as to whether type 2 diabetes mellitus (T2DM) impairs clinical outcome from immune checkpoint inhibitors (ICI) in patients with solid tumors. EXPERIMENTAL DESIGN: In a large cohort of ICI recipients treated at 21 institutions from June 2014 to June 2020, we studied whether patients on glucose-lowering medications (GLM) for T2DM had shorter overall survival (OS) and progression-free survival (PFS). We used targeted transcriptomics in a subset of patients to explore differences in the tumor microenvironment (TME) of patients with or without diabetes. RESULTS: A total of 1,395 patients were included. Primary tumors included non-small cell lung cancer (NSCLC; 54.7%), melanoma (24.7%), renal cell (15.0%), and other carcinomas (5.6%). After multivariable analysis, patients on GLM (n = 226, 16.2%) displayed an increased risk of death [HR, 1.29; 95% confidence interval (CI),1.07-1.56] and disease progression/death (HR, 1.21; 95% CI, 1.03-1.43) independent of number of GLM received. We matched 92 metformin-exposed patients with 363 controls and 78 patients on other oral GLM or insulin with 299 control patients. Exposure to metformin, but not other GLM, was associated with an increased risk of death (HR, 1.53; 95% CI, 1.16-2.03) and disease progression/death (HR, 1.34; 95% CI, 1.04-1.72). Patients with T2DM with higher pretreatment glycemia had higher neutrophil-to-lymphocyte ratio (P = 0.04), while exploratory tumoral transcriptomic profiling in a subset of patients (n = 22) revealed differential regulation of innate and adaptive immune pathways in patients with T2DM. CONCLUSIONS: In this study, patients on GLM experienced worse outcomes from immunotherapy, independent of baseline features. Prospective studies are warranted to clarify the relative impact of metformin over a preexisting diagnosis of T2DM in influencing poorer outcomes in this population.

A Fe2+-dependent self-inhibited state influences the druggability of human collagen lysyl hydroxylase (LH/PLOD) enzymes.

Multifunctional human collagen lysyl hydroxylase (LH/PLOD) enzymes catalyze post-translational hydroxylation and subsequent glycosylation of collagens, enabling their maturation and supramolecular organization in the extracellular matrix (ECM). Recently, the overexpression of LH/PLODs in the tumor microenvironment results in abnormal accumulation of these collagen post-translational modifications, which has been correlated with increased metastatic progression of a wide variety of solid tumors. These observations make LH/PLODs excellent candidates for prospective treatment of aggressive cancers. The recent years have witnessed significant research efforts to facilitate drug discovery on LH/PLODs, including molecular structure characterizations and development of reliable high-throughput enzymatic assays. Using a combination of biochemistry and in silico studies, we characterized the dual role of Fe2+ as simultaneous cofactor and inhibitor of lysyl hydroxylase activity and studied the effect of a promiscuous Fe2+ chelating agent, 2,2'-bipyridil, broadly considered a lysyl hydroxylase inhibitor. We found that at low concentrations, 2,2'-bipyridil unexpectedly enhances the LH enzymatic activity by reducing the inhibitory effect of excess Fe2+. Together, our results show a fine balance between Fe2+-dependent enzymatic activity and Fe2+-induced self-inhibited states, highlighting exquisite differences between LH/PLODs and related Fe2+, 2-oxoglutarate dioxygenases and suggesting that conventional structure-based approaches may not be suited for successful inhibitor development. These insights address outstanding questions regarding druggability of LH/PLOD lysyl hydroxylase catalytic site and provide a solid ground for upcoming drug discovery and screening campaigns.

PD-1/PD-L1 checkpoint inhibitors during late stages of life: an ad-hoc analysis from a large multicenter cohort.

BACKGROUND: The favourable safety profile and the increasing confidence with immune checkpoint inhibitors (ICIs) might have boosted their prescription in frail patients with short life expectancies, who usually are not treated with standard chemotherapy. METHODS: The present analysis aims to describe clinicians' attitudes towards ICIs administration during late stages of life within a multicenter cohort of advanced cancer patients treated with single agent PD-1/PD-L1 checkpoint inhibitors in Italy. RESULTS: Overall, 1149 patients with advanced cancer who received single agent PD-1/PD-L1 checkpoint inhibitors were screened. The final study population consisted of 567 deceased patients. 166 patients (29.3%) had received ICIs within 30 days of death; among them there was a significantly higher proportion of patients with ECOG-PS ≥ 2 (28.3% vs 11.5%, p < 0.0001) and with a higher burden of disease (69.3% vs 59.4%, p = 0.0266). In total, 35 patients (6.2%) started ICIs within 30 days of death; among them there was a higher proportion of patients with ECOG-PS ≥ 2 (45.7% vs 14.5%, p < 0.0001) and with a higher burden of disease (82.9% vs 60.9%, p = 0.0266). Primary tumors were significantly different across subgroups (p = 0.0172), with a higher prevalence of NSCLC patients (80% vs 60.9%) among those who started ICIs within 30 days of death. Lastly, 123 patients (21.7%) started ICIs within 3 months of death. Similarly, within this subgroup there was a higher proportion of patients with ECOG-PS ≥ 2 (29.3% vs 12.8%, p < 0.0001), with a higher burden of disease (74.0% vs 59.0%, p = 0.0025) and with NSCLC (74.0% vs 58.8%, p = 0.0236). CONCLUSION: Our results confirmed a trend toward an increasing ICIs prescription in frail patients, during the late stages of life. Caution should be exercised when evaluating an ICI treatment for patients with a poor PS and a high burden of disease.

Obesity treatment within the Italian national healthcare system tertiary care centers: what can we learn?

INTRODUCTION: The prevalence of obesity is soaring all over the world, and Italy is reaching the same pace. Similar to other countries, the Italian healthcare system counts on a three-tier model for obesity care, and each region has freedom in the implementation of guidelines. No national record is currently available to monitor the actual situation throughout the country. PURPOSE: To provide a report of the current status on the availability of specialized public obesity care services in Italy. METHODS: Regional prevalence of obesity was extrapolated from publicly available data. Data on facilities for the management of obesity were retrieved from records provided by national scientific societies. Whenever possible, data was verified through online research and direct contact. RESULTS: We report a north-south and east-west gradient regarding the presence of obesity focused facilities, with an inverse correlation with the regional prevalence of obesity (R = 0.25, p = 0.03). Medical-oriented centers appear homogeneous in the multidisciplinary approach, the presence of a bariatric surgery division, the availability of support materials and groups, with no major difference on follow-up frequency. Surgery-oriented centers have a more capillary territorial distribution than the medically oriented, but not enough data was retrieved to provide a thorough description of their characteristics. CONCLUSION: Obtaining a clear picture of the situation and providing consistent care across the country is a challenging task due to the decentralized organization of regions. We provide a first sketch, reporting that the model is applied unevenly, and we suggest feasible actions to improve the situation in our country and elsewhere. LEVEL OF EVIDENCE: Level V, narrative review.

Mail from Heaven.

A moving story about the nature of the doctor­patient relationship, this narrative describes a letter of gratitude from a breast cancer patient, written shortly before her death.

Overweight and obese patients with nickel allergy have a worse metabolic profile compared to weight matched non-allergic individuals.

BACKGROUND: A lack of balance between energy intake and expenditure due to overeating or reduced physical activity does not seem to explain entirely the obesity epidemic we are facing, and further factors are therefore being evaluated. Nickel (Ni) is a ubiquitous heavy metal implied in several health conditions. Regarding this, the European Food Safety Authority has recently released an alert on the possible deleterious effects of dietary Ni on human health given the current levels of Ni dietary intake in some countries. Pre-clinical studies have also suggested its role as an endocrine disruptor and have linked its exposure to energy metabolism and glucose homeostasis dysregulation. Ni allergy is common in the general population, but preliminary data suggest it being even more widespread among overweight patients. OBJECTIVES: The aim of this study has been to evaluate the presence of Ni allergy and its association with the metabolic and endocrine profile in overweight and obese individuals. METHODS: We have evaluated 1128 consecutive overweight and obese outpatients. 784 were suspected of being allergic to Ni and 666 were assessed for it. Presence of Ni allergy and correlation with body mass index (BMI), body composition, metabolic parameters and hormonal levels were evaluated. RESULTS: We report that Ni allergy is more frequent in presence of weight excess and is associated with worse metabolic parameters and impaired Growth Hormone secretion. CONCLUSIONS: We confirm that Ni allergy is more common in obese patients, and we report for the first time its association with worse metabolic parameters and impaired function of the GH-IGF1 axis in human subjects.

Medical oncologist's commitment in end-of-life care of cancer patients.

OBJECTIVE: Cancer patients and family members can feel abandoned by their oncologist at the transition to end-of-life (eoL) care. In this study, we evaluated the level of satisfaction of family caregivers when the oncology team assisted the patient until death. METHODS: Two oncology units were reorganized to ensure continuity of care; oncologists trained in palliative care medicine assisted patients until death. Relatives who assisted the patient at home or at an inpatient hospice underwent a semi-structured phone interview >1 month after the patient's death. Satisfaction was measured using a five-point Likert scale ranging from very dissatisfied (score 0) to very satisfied (score 100). RESULTS: Relatives of 65 patients were contacted, 55 accepted the interview. Patients were followed at home (41) or at an inpatient hospice (14), for 1-24 weeks (median 3 weeks). A specific question on the relevance of the oncologist having a role in EoL care produced a score of 82. The overall satisfaction score was higher than in our previous study in which a continuity of care model was not adopted, with a score improvement from 55/100 to 84/100 (p < 0.001). SIGNIFICANCE OF RESULTS: A care program where the oncologist is involved in EoL management improved the satisfaction of caregivers of cancer patients. When a longstanding and trusting relationship has been established, the connection between the patient and the oncologist should not be lost.

Abrogating G2/M checkpoint through WEE1 inhibition in combination with chemotherapy as a promising therapeutic approach for mesothelioma.

Malignant mesothelioma (MM) is a very aggressive asbestos-related neoplasm of the serous membranes, whose incidence is increasing worldwide. Although the introduction of new drug combinations, such as cisplatin plus pemetrexed/gemcitabine, has determined an improvement in the patient quality of life, MM remains a universally fatal disease. The observation that key G 1/S checkpoint regulators are often functionally inactivated in MM prompted us to test whether the use of G 2/M checkpoint inhibitors, able to sensitize G 1/S checkpoint-defective cancer cells to DNA-damaging agents, could be successful in MM. We treated six MM cell lines, representative of different histotypes (epithelioid, biphasic, and sarcomatoid), with cisplatin in combination with MK-1775, an inhibitor of the G 2/M checkpoint kinase WEE1. We observed that MK-1775 enhanced the cisplatin cytotoxic effect in all MM cell lines, except the sarcomatoid cell line, which is representative of the most aggressive histotype. As expected, the enhancement in cisplatin toxicity was accompanied by a decrease in the inactive phosphorylated form of cyclin-dependent kinase 1 (CDK1), a key substrate of WEE1, which is indicative of G 2/M checkpoint inactivation. Consistently, we also observed a decrease in G 2/M accumulation and an increase in mitotic entry of DNA-damaged cells and apoptosis, probably due to the loss of the cell ability to arrest cell cycle in response to DNA damage, irrespectively of p53 mutational status. Notably, this treatment did not increase cisplatin cytotoxicity on normal cells, thus suggesting a possible use of MK-1775 in combination with cisplatin for a safe and efficient treatment of epithelioid and biphasic MM.

Pharmacological targeting of p53 through RITA is an effective antitumoral strategy for malignant pleural mesothelioma.

Malignant mesothelioma, a very aggressive tumor associated to asbestos exposure, is expected to increase in incidence, and unfortunately, no curative modality exists. Reactivation of p53 is a new attractive antitumoral strategy. p53 is rarely mutated in mesothelioma, but it is inactivated in most tumors by the lack of p14(ARF). Here, we evaluated the feasibility of this approach in pleural mesothelioma by testing RITA and nutlin-3, two molecules able to restore p53 function through a different mechanism, on a panel of mesothelioma cell lines representing the epithelioid (NCI-H28, NCI-H2452, IST-MES 2), biphasic (MSTO-211H), and sarcomatoid (NCI-H2052) histotypes compared with the normal mesothelial HMC-hTERT. RITA triggered robust caspase-dependent apoptosis specifically in epithelioid and biphasic mesothelioma cell lines, both through wild-type and mutant p53, concomitant to p21 downregulation. Conversely, nutlin-3 induced a p21-dependent growth arrest, rather than apoptosis, and was slightly toxic on HMC-hTERT.   Interestingly, we identified a previously undetected point mutation of p53 (p.Arg249Ser) in IST-MES 2, and showed that RITA is also able to reactivate this p53 mutant protein and its apoptotic function. RITA reduced tumor growth in a MSTO-211H-derived xenograft model of mesothelioma and synergized with cisplatin, which is the mainstay of treatment for this tumor. Our data indicate that reactivation of p53 and concomitant p21 downregulation effectively induce cell death in mesothelioma, a tumor characterized by a high intrinsic resistance to apoptosis. Altogether, our findings provide the preclinical framework supporting the use of p53-reactivating agents alone, or in combination regimens, to improve the outcome of patients with mesothelioma.

Identification and super-resolution imaging of ligand-activated receptor dimers in live cells.

Molecular interactions are key to many chemical and biological processes like protein function. In many signaling processes they occur in sub-cellular areas displaying nanoscale organizations and involving molecular assemblies. The nanometric dimensions and the dynamic nature of the interactions make their investigations complex in live cells. While super-resolution fluorescence microscopies offer live-cell molecular imaging with sub-wavelength resolutions, they lack specificity for distinguishing interacting molecule populations. Here we combine super-resolution microscopy and single-molecule Förster Resonance Energy Transfer (FRET) to identify dimers of receptors induced by ligand binding and provide super-resolved images of their membrane distribution in live cells. By developing a two-color universal-Point-Accumulation-In-the-Nanoscale-Topography (uPAINT) method, dimers of epidermal growth factor receptors (EGFR) activated by EGF are studied at ultra-high densities, revealing preferential cell-edge sub-localization. This methodology which is specifically devoted to the study of molecules in interaction, may find other applications in biological systems where understanding of molecular organization is crucial.

HIPK1 drives p53 activation to limit colorectal cancer cell growth.

HIPK1 (homeodomain interacting protein kinase 1) is a serine/threonine kinase that belongs to the CMGC superfamily. Emerging data point to the role of HIPK1 in cancer, but it is still not clear whether it acts as a tumor suppressor or promoter. Here we identified HIPK1 as a kinase that is significantly overexpressed in colorectal cancer (CRC) and whose expression is stage-dependent. Being abundantly expressed at the onset of the disease, the HIPK1 level gradually decreased as tumor stage progressed. To further uncover how this factor regulates tumorigenesis and establish whether it constitutes an early factor necessary for neoplastic transformation or for cellular defense, we studied the effect of its overexpression in vitro by investigating various cancer-related signaling cascades. We found that HIPK1 mostly regulates the p53 signaling pathway both in HCT116 and HeLa cells. By phosphorylating p53 on its serine-15, HIPK1 favored its transactivation potential, which led to a rise in p21 protein level and a decline in cell proliferation. Assuming that HIPK1 could impede CRC growth by turning on the p53/p21 pathway, we then checked p21 mRNA levels in patients. Interestingly, p21 transcripts were only increased in a subset of patients expressing high levels of HIPK1. Unlike the rest of the cohort, the majority of these patients hosted a native p53 protein, meaning that such a pro-survival pathway (HIPK1+ > p53 > p21) is active in patients, and that HIPK1 acts rather as a tumor suppressor.

Synthesis and evaluation of apoptosis induction of thienopyrimidine compounds on KRAS and BRAF mutated colorectal cancer cell lines.

Monoclonal antibodies (MoAb) and tyrosine kinase inhibitors (TKI) targeting the EGFR (Epidermal Growth Factor Receptor) pathways are currently used in colorectal cancer treatment. Despite the improvement of median overall survival, resistance is observed notably due to KRAS and BRAF gene mutations. We synthesized four series of thienopyrimidines whose scaffold is structurally close to TKI used in clinical practice. We evaluated apoptosis induced by these compounds using flow cytometry on KRAS and BRAF mutated cell lines. Our results confirm that the mutated cell lines (HCT116 and HT29) are more resistant to apoptosis than the non-mutated cell line (Hela). Interestingly, among the 13 compounds tested, three of them (5b, 6b and 6d) and gefitinib exhibited a noteworthy pro-apoptotic effect, especially on mutated cell lines with an IC(50) value between 70 and 110µM. These three compounds seem particularly attractive for the development of novel treatments for colorectal cancer patients harboring EGFR pathway mutations.

Non-antioxidant properties of α-tocopherol reduce the anticancer activity of several protein kinase inhibitors in vitro.

The antioxidant properties of α-tocopherol have been proposed to play a beneficial chemopreventive role against cancer. However, emerging data also indicate that it may exert contrasting effects on the efficacy of chemotherapeutic treatments when given as dietary supplement, being in that case harmful for patients. This dual role of α-tocopherol and, in particular, its effects on the efficacy of anticancer drugs remains poorly documented. For this purpose, we studied here, using high throughput flow cytometry, the direct impact of α-tocopherol on apoptosis and cell cycle arrest induced by different cytotoxic agents on various models of cancer cell lines in vitro. Our results indicate that physiologically relevant concentrations of α-tocopherol strongly compromise the cytotoxic and cytostatic action of various protein kinase inhibitors (KI), while other classes of chemotherapeutic agents or apoptosis inducers are unaffected by this vitamin. Interestingly, these anti-chemotherapeutic effects of α-tocopherol appear to be unrelated to its antioxidant properties since a variety of other antioxidants were completely neutral toward KI-induced cell cycle arrest and cell death. In conclusion, our data suggest that dietary α-tocopherol could limit KI effects on tumour cells, and, by extent, that this could result in a reduction of the clinical efficacy of anti-cancer treatments based on KI molecules.

The polyphenolic ellagitannin vescalagin acts as a preferential catalytic inhibitor of the α isoform of human DNA topoisomerase II.

Polyphenolic ellagitannins are natural compounds that are often associated with the therapeutic activity of plant extracts used in traditional medicine. They display cancer-preventing activity in animal models by a mechanism that remains unclear. Potential targets have been proposed, including DNA topoisomerases II (Top2). Top2α and Top2ß, the two isoforms of the human Top2, play a crucial role in the regulation of replication, transcription, and chromosome segregation. They are the target of anticancer agents used in the clinic such as anthracyclines (e.g., doxorubicin) or the epipodophyllotoxin etoposide. It was recently shown that the antitumor activity of etoposide was due primarily to the inhibition of Top2α, whereas inhibition of Top2ß was responsible for the development of secondary malignancies, pointing to the need for more selective Top2α inhibitors. Here, we show that the polyphenolic ellagitannin vescalagin preferentially inhibits the decatenation activity of Top2α in vitro, by a redox-independent mechanism. In CEM cells, we also show that transient small interfering RNA-mediated down-regulation of Top2α but not of Top2ß conferred a resistance to vescalagin, indicating that the α isoform is a preferential target. We further confirmed that Top2α inhibition was due to a catalytic inhibition of the enzyme because it did not induce DNA double-strand breaks in CEM-treated cells but prevented the formation of Top2α- rather than Top2ß-DNA covalent complexes induced by etoposide. To our knowledge, vescalagin is the first example of a catalytic inhibitor for which cytotoxicity is due, at least in part, to the preferential inhibition of Top2α.