Heparin Protects Human Neural Progenitor Cells from Zika Virus-Induced Cell Death While Preserving Their Differentiation into Mature Neuroglial Cells.

Zika virus (ZIKV) is an arbovirus member of the Flaviviridae family that causes severe congenital brain anomalies in infected fetuses. The key target cells of ZIKV infection, human neural progenitor cells (hNPCs), are highly permissive to infection that causes the inhibition of cell proliferation and induces cell death. We have previously shown that pharmaceutical-grade heparin inhibits virus-induced cell death with negligible effects on in vitro virus replication in ZIKV-infected hNPCs at the "high" multiplicity of infection (MOI) of 1. Here, we show that heparin inhibits formation of ZIKV-induced intracellular vacuoles, a signature of paraptosis, and inhibits necrosis and apoptosis of hNPCs grown as neurospheres (NS). To test whether heparin preserved the differentiation of ZIKV-infected hNPCs into neuroglial cells, hNPCs were infected at the MOI of 0.001. In this experimental condition, heparin inhibited ZIKV replication by ca. 2 log10, mostly interfering with virion attachment, while maintaining its protective effect against ZIKV-induced cytopathicity. Heparin preserved differentiation into neuroglial cells of hNPCs that were obtained from either human-induced pluripotent stem cells (hiPSC) or by fetal tissue. Quite surprisingly, multiple additions of heparin to hNPCs enabled prolonged virus replication while preventing virus-induced cytopathicity. Collectively, these results highlight the potential neuroprotective effect of heparin that could serve as a lead compound to develop novel agents for preventing the damage of ZIKV infection on the developing brain. IMPORTANCE ZIKV is a neurotropic virus that invades neural progenitor cells (NPCs), causing inhibition of their proliferation and maturation into neurons and glial cells. We have shown previously that heparin, an anticoagulant also used widely during pregnancy, prevents ZIKV-induced cell death with negligible inhibition of virus replication. Here, we demonstrate that heparin also exerts antiviral activity against ZIKV replication using a much lower infectious inoculum. Moreover, heparin interferes with different modalities of virus-induced cell death. Finally, heparin-induced prevention of virus-induced NPC death allows their differentiation into neuroglial cells despite the intracellular accumulation of virions. These results highlight the potential use of heparin, or pharmacological agents derived from it, in pregnant women to prevent the devastating effects of ZIKV infection on the developing brain of their fetuses.

Modulation of NBAS-Related Functions in the Early Response to SARS-CoV-2 Infection.

Upon infection, severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) is predicted to interact with diverse cellular functions, such as the nonsense-mediated decay (NMD) pathway, as suggested by the identification of the core NMD factor upframeshift-1 (UPF1) in the SARS-CoV-2 interactome, and the retrograde transport from the Golgi to the endoplasmic reticulum (ER) through the endoplasmic reticulum-Golgi intermediate compartment (ERGIC), where coronavirus assembly occurs. Here, we investigated the expression and localization of the neuroblastoma-amplified sequence (NBAS) protein, a UPF1 partner for the NMD at the ER, participating also in retrograde transport, and of its functional partners, at early time points after SARS-CoV-2 infection of the human lung epithelial cell line Calu3. We found a significant decrease of DExH-Box Helicase 34 (DHX34), suppressor with morphogenetic effect on genitalia 5 (SMG5), and SMG7 expression at 6 h post-infection, followed by a significant increase of these genes and also UPF1 and UPF2 at 9 h post-infection. Conversely, NBAS and other genes coding for NMD factors were not modulated. Known NMD substrates related to cell stress (Growth Arrest Specific 5, GAS5; transducin beta-like 2, TBL2; and DNA damage-inducible transcript 3, DDIT3) were increased in infected cells, possibly as a result of alterations in the NMD pathway and of a direct effect of the infection. We also found that the expression of unconventional SNARE in the ER 1, USE1 (p31) and Zeste White 10 homolog, ZW10, partners of NBAS in the retrograde transport function, significantly increased over time in infected cells. Co-localization of NBAS and UPF1 proteins did not change within 24 h of infection nor did it differ in infected versus non-infected cells at 1 and 24 h after infection; similarly, the co-localization of NBAS and p31 proteins was not altered by infection in this short time frame. Finally, both NBAS and UPF1 were found to co-localize with SARS-CoV-2 S and N proteins. Overall, these data are preliminary evidence of an interaction between NBAS and NBAS-related functions and SARS-CoV-2 in infected cells, deserving further investigation.

The Long and Winding Road Towards an HIV Cure.

In the summer of 1981, a new deadly disease suddenly emerged targeting young men having sexwith men (MSM); three years later, a new virus, an exogenous human retrovirus, later named humanimmunodeficiency virus (HIV), was demonstrated to be the causative agent of the new disease, theAcquired Immuno-Deficiency Syndrome (AIDS), affecting, in addition to MSM, also intravenousdrug users, hemophiliacs, heterosexual individuals and children born to infected mothers. AIDSremained a dead sentence for >95% infected individuals until 1996 when the first combinationantiretroviral therapy (cART) was shown to be effective saving the lives of countless people. Sincethen, cART has become extremely powerful and simpler to adhere (now down to one or two pillsa day). However, virus eradication ("Cure") has been achieved thus far only in two individuals asa result of stem cell transplantation by an immunologically compatible donor homozygote for theCCR5Δ32 mutation; CCR5 is indeed the major entry coreceptor for the virus together with theprimary receptor CD4. This represents the exception to the rule that none of the many experimentalattempts of eliminating or silencing the virus reservoir unaffected by cART has achieved a significantproof of concept. In this article we will describe the essential aspects of the viral reservoirs and thecurrent strategies to tackle it.

Host Restriction Factors Modulating HIV Latency and Replication in Macrophages.

In addition to CD4+ T lymphocytes, myeloid cells and, particularly, differentiated macrophages are targets of human immunodeficiency virus type-1 (HIV-1) infection via the interaction of gp120Env with CD4 and CCR5 or CXCR4. Both T cells and macrophages support virus replication, although with substantial differences. In contrast to activated CD4+ T lymphocytes, HIV-1 replication in macrophages occurs in nondividing cells and it is characterized by the virtual absence of cytopathicity both in vitro and in vivo. These general features should be considered in evaluating the role of cell-associated restriction factors aiming at preventing or curtailing virus replication in macrophages and T cells, particularly in the context of designing strategies to tackle the viral reservoir in infected individuals receiving combination antiretroviral therapy. In this regard, we will here also discuss a model of reversible HIV-1 latency in primary human macrophages and the role of host factors determining the restriction or reactivation of virus replication in these cells.

HER2 Positivity Predicts Unresponsiveness to EGFR-Targeted Treatment in Metastatic Colorectal Cancer.

BACKGROUND: HER2 amplification is detected in 3% of patients with colorectal cancer (CRC), making tumors in the metastatic setting vulnerable to double pharmacological HER2 blockade. Preclinical findings show that it also might impair response to anti-epidermal growth factor receptor (EGFR) treatment. SUBJECTS AND METHODS: Patients with KRAS exon 2 wild-type metastatic CRC underwent molecular screening of HER2 positivity by HERACLES criteria (immunohistochemistry 3+ or 2+ in ≥50% of cells, confirmed by fluorescence in situ hybridization). A sample of consecutive HER2-negative patients was selected as control. A regression modeling strategy was applied to identify predictors explaining the bulk of HER2 positivity and the association with response to previous anti-EGFR treatment. RESULTS: From August 2012 to April 2018, a total of 100 HER2-positive metastatic CRC tumors were detected out of 1,485 KRAS exon 2 wild-type screened patients (6.7%). HER2-positive patients show more frequently lung metastases (odds ratio [OR], 2.04; 95% confidence interval [CI], 1.15-3.61; p = .014) and higher tumor burden (OR, 1.48; 95% CI, 1.10-2.01; p = .011), and tumors were more likely to be left sided (OR, 0.50; 95% CI, 0.22-1.11; p = .088). HER2-positive patients who received treatment with anti-EGFR agents (n = 79) showed poorer outcome (objective response rate, 31.2% vs. 46.9%, p = .031; progression-free survival, 5.7 months vs. 7 months, p = .087). CONCLUSION: Testing for HER2 should be offered to all patients with metastatic CRC because the occurrence of this biomarker is unlikely to be predicted based on main clinicopathological features. Patients with HER2-amplified metastatic CRC are less likely to respond to anti-EGFR therapy. IMPLICATIONS FOR PRACTICE: Patients with HER2-amplified/overexpressed metastatic colorectal cancer (mCRC) harbor a driver actionable molecular alteration that has been shown in preclinical models to hamper efficacy of the anti-epidermal growth factor receptor (EGFR) targeted therapies. The present study confirmed that this molecular feature was associated with worse objective tumor response and shorter progression-free survival in response to previous anti-EGFR therapies. Moreover, it was found that the occurrence of this biomarker is unlikely to be predicted based on main clinicopathological features. Therefore, HER2 status assessment should be included in the molecular diagnostic workup of all mCRC for speedy referral to clinical trials encompassing HER2-targeted double blockade independently of previous anti-EGFR treatment.

Subverting the mechanisms of cell death: flavivirus manipulation of host cell responses to infection.

Viruses exploit host metabolic and defence machinery for their own replication. The flaviviruses, which include Dengue (DENV), Yellow Fever (YFV), Japanese Encephalitis (JEV), West Nile (WNV) and Zika (ZIKV) viruses, infect a broad range of hosts, cells and tissues. Flaviviruses are largely transmitted by mosquito bites and humans are usually incidental, dead-end hosts, with the notable exceptions of YFV, DENV and ZIKV. Infection by flaviviruses elicits cellular responses including cell death via necrosis, pyroptosis (involving inflammation) or apoptosis (which avoids inflammation). Flaviviruses exploit these mechanisms and subvert them to prolong viral replication. The different effects induced by DENV, WNV, JEV and ZIKV are reviewed. Host cell surface proteoglycans (PGs) bearing glycosaminoglycan (GAG) polysaccharides - heparan/chondroitin sulfate (HS/CS) - are involved in initial flavivirus attachment and during the expression of non-structural viral proteins play a role in disease aetiology. Recent work has shown that ZIKV-infected cells are protected from cell death by exogenous heparin (a GAG structurally similar to host cell surface HS), raising the possibility of further subtle involvement of HS PGs in flavivirus disease processes. The aim of this review is to synthesize information regarding DENV, WNV, JEV and ZIKV from two areas that are usually treated separately: the response of host cells to infection by flaviviruses and the involvement of cell surface GAGs in response to those infections.

Dual-targeted therapy with trastuzumab and lapatinib in treatment-refractory, KRAS codon 12/13 wild-type, HER2-positive metastatic colorectal cancer (HERACLES): a proof-of-concept, multicentre, open-label, phase 2 trial.

BACKGROUND: We previously found that dual HER2 blockade with trastuzumab and lapatinib led to inhibition of tumour growth in patient-derived xenografts of HER2-amplified metastatic colorectal cancer. In this study, we aimed to assess the antitumour activity of trastuzumab and lapatinib in patients with HER2-positive colorectal cancer. METHODS: HERACLES was a proof-of-concept, multicentre, open-label, phase 2 trial done at four Italian academic cancer centres. We enrolled adult patients with KRAS exon 2 (codons 12 and 13) wild-type and HER2-positive metastatic colorectal cancer refractory to standard of care (including cetuximab or panitumumab), an Eastern Cooperative Oncology Group performance status of 0 or 1, and at least one measurable lesion. We defined HER2 positivity in tumour samples by use of immunohistochemistry and fluorescence in-situ hybridisation in accordance with our previously validated colorectal cancer-specific diagnostic criteria. Eligible patients received intravenous trastuzumab at 4 mg/kg loading dose followed by 2 mg/kg once per week, and oral lapatinib at 1000 mg per day until evidence of disease progression. The primary endpoint was the proportion of patients achieving an objective response (defined as complete response or partial response), which was assessed by independent central review in the intention-to-treat population. This trial is registered with EudraCT, number 2012-002128-33. FINDINGS: Between Aug 27, 2012, and May 15, 2015, we screened 914 patients with KRAS exon 2 (codons 12 and 13) wild-type metastatic colorectal cancer and identified 48 (5%) patients with HER2-positive tumours, although two died before enrolment. Of these patients, 27 were eligible for the trial. All were evaluable for response. At the time of data cutoff on Oct 15, 2015, with a median follow-up of 94 weeks (IQR 51-127), eight (30%, 95% CI 14-50) of 27 patients had achieved an objective response, with one patient (4%, 95% CI -3 to 11) achieving a complete response, and seven (26%, 95% CI 9-43) achieving partial responses; 12 (44%, 95% CI 25-63) patients had stable disease. Six (22%) of 27 patients had grade 3 adverse events, which consisted of fatigue in four patients, skin rash in one patient, and increased bilirubin concentration in one patient. No grade 4 or 5 adverse events were reported. We detected no drug-related serious adverse events. INTERPRETATION: The combination of trastuzumab and lapatinib is active and well tolerated in treatment-refractory patients with HER2-positive metastatic colorectal cancer. FUNDING: Associazione Italiana Ricerca Cancro (AIRC), Fondazione Oncologia Niguarda Onlus, and Roche.

The MHC-II transactivator CIITA inhibits Tat function and HIV-1 replication in human myeloid cells.

BACKGROUND: We previously demonstrated that the HLA class II transactivator CIITA inhibits HIV-1 replication in T cells by competing with the viral transactivator Tat for the binding to Cyclin T1 subunit of the P-TEFb complex. Here, we analyzed the anti-viral function of CIITA in myeloid cells, another relevant HIV-1 target cell type. We sinvestigated clones of the U937 promonocytic cell line, either permissive (Plus) or non-permissive (Minus) to HIV-1 replication. This different phenotype has been associated with the expression of TRIM22 in U937 Minus but not in Plus cells. METHODS: U937 Plus cells stably expressing CIITA were generated and HLA-II positive clones were selected by cell sorting and cloning. HLA and CIITA proteins were analyzed by cytofluorometry and western blotting, respectively. HLA-II DR and CIITA mRNAs were quantified by qRT-PCR. Tat-dependent transactivation was assessed by performing the HIV-1 LTR luciferase gene reporter assay. Cells were infected with HIV-1 and viral replication was evaluated by measuring the RT activity in culture supernatants. RESULTS: CIITA was expressed only in HLA-II-positive U937 Minus cells, and this was strictly correlated with inhibition of Tat-dependent HIV-1 LTR transactivation in Minus but not in Plus cells. Overexpression of CIITA in Plus cells restored the suppression of Tat transactivation, confirming the inhibitory role of CIITA. Importantly, HIV-1 replication was significantly reduced in Plus-CIITA cells with respect to Plus parental cells. This effect was independent of TRIM22 as CIITA did not induce TRIM22 expression in Plus-CIITA cells. CONCLUSIONS: U937 Plus and Minus cells represent an interesting model to study the role of CIITA in HIV-1 restriction in the monocytic/macrophage cell lineage. The differential expression of CIITA in CIITA-negative Plus and CIITA-positive Minus cells correlated with their capacity to support or not HIV-1 replication, respectively. In Minus cells CIITA targeted the viral transactivator Tat to inhibit HIV-1 replication. The generation of Plus-CIITA cells was instrumental to demonstrate the specific contribution of CIITA in terms of inhibition of Tat activity and HIV-1 restriction, independently from other cellular factors, including TRIM22. Thus, CIITA acts as a general restriction factor against HIV-1 not only in T cells but also in myeloid cells.

Characterization of HIV-1 entry inhibitors with broad activity against R5 and X4 viral strains.

BACKGROUND: Combined antiretroviral therapy has drastically reduced mortality and morbidity of HIV-infected individuals. Nevertheless long-term toxicity and appearance of viral resistance hampers the prolonged effectiveness of combination therapy, requiring a continuous input of drugs to replace those utilized in combination regimens. We here investigated the anti-HIV activity of novel derivatives of the suradista chemical class. METHODS: Compounds were tested on acute HIV-1 infection of activated peripheral blood mononuclear cells. HIV production was monitored by enzyme-linked immunosorbent assay measuring the protein p24 released in culture supernatants. Fusion assays were carried out to study the mechanism of action of these compounds. A modified version of a previously established recombinant vaccinia virus-based assay was used measuring activation of a reporter gene upon fusion of two distinct cell populations. Flow cytometry was performed in competition assays for the binding of several antibodies targeting different sites of the viral envelope glycoprotein gp120, or the receptor CD4, or the coreceptors CXCR4 and CCR5. RESULTS: Four compounds inhibited replication of a prototypic R5 (BaL) and X4 (IIIB) laboratory-adapted HIV-1 strain at low micromolar concentrations, in the absence of cytotoxicity. Approximately a ten fold greater activity was achieved against the X4 as compared to the R5 strain. The compounds blocked X4 and R5 HIV-1 fusion, a step of viral entry. This activity appeared specific for HIV-1, as entry of human herpesvirus 6 (HHV-6) and influenza virus was not substantially affected. Further investigation of the inhibitory mechanism revealed that these new molecules target the viral envelope, rather than the coreceptors, as previously shown for a congener of the same class characterized by a long plasmatic half-life. Indeed ND-4043, the most active compound, specifically competed with binding of monoclonal antibodies against the CD4-binding site (CD4-BS) and coreceptor-binding site (CoR-BS) of gp120. These compounds displayed broad anti-HIV activity, as they inhibited various primary R5, X4 and, importantly, dualtropic R5X4 HIV-1 isolates. Of the four derivatives tested, the dimeric compounds were consistently more potent than the monomeric ones. CONCLUSIONS: Given their unique features, these molecules represent promising candidates for further development and exploitation as anti-HIV therapeutics.

Spontaneous control of HIV-1 viremia in a subject with protective HLA-B plus HLA-C alleles and HLA-C associated single nucleotide polymorphisms.

INTRODUCTION: Understanding the mechanisms by which some individuals are able to naturally control HIV-1 infection is an important goal of AIDS research. We here describe the case of an HIV-1(+) woman, CASE1, who has spontaneously controlled her viremia for the last 14 of her 20 years of infection. METHODS: CASE1 has been clinically monitored since 1993. Detailed immunological, virological and histological analyses were performed on samples obtained between 2009 and 2011. RESULTS: As for other Elite Controllers, CASE1 is characterized by low to undetectable levels of plasma HIV-1 RNA, peripheral blood mononuclear cell (PBMC) associated HIV-1 DNA and reduced in vitro susceptibility of target cells to HIV-1 infection. Furthermore, a slow rate of virus evolution was demonstrated in spite the lack of assumption of any antiretroviral agent. CASE1 failed to transmit HIV-1 to either her sexual male partner or to her child born by vaginal delivery. Normal values and ratios of T and B cells were observed, along with normal histology of the intestinal mucosa. Attempts to isolate HIV-1 from her PBMC and gut-derived cells were unsuccessful, despite expression of normal cell surface levels of CD4, CCRC5 and CXCR4. CASE1 did not produce detectable anti-HIV neutralizing antibodies in her serum or genital mucosal fluid although she displayed potent T cell responses against HIV-1 Gag and Nef. CASE1 also possessed multiple genetic polymorphisms, including HLA alleles (B*14, B*57, C*06 and C*08.02) and HLA-C single nucleotide polymorphisms (SNPs, rs9264942 C/C and rs67384697 del/del), that have been previously individually associated with spontaneous control of plasma viremia, maintenance of high CD4(+) T cell counts and delayed disease progression. CONCLUSIONS: CASE1 has controlled her HIV-1 viremia below the limit of detection in the absence of antiretroviral therapy for more than 14 years and has not shown any sign of immunologic deterioration or disease progression. Co-expression of multiple protective HLA alleles, HLA-C SNPs and strong T cell responses against HIV-1 proteins are the most likely explanation of this very benign case of spontaneous control of HIV-1 disease progression.

HIV-1 envelope-dependent restriction of CXCR4-using viruses in child but not adult untransformed CD4+ T-lymphocyte lines.

Phytohemagglutin-stimulated child and adult leukocytes equally supported CCR5-dependent (R5) and CXCR4-dependent (X4) HIV-1 replication. In contrast, when phytohemagglutin-stimulated leukocytes from either healthy or congenitally immunodeficient children were cultured on feeder cells, they well supported R5, but not X4 HIV-1 replication, whereas both viruses equally spread in adult cells maintained in similar conditions. Both child and adult cells showed similar levels of proliferation and surface expression of CD4, CCR5, CXCR4, CD25, CD69, and HLA-DR. Lack of X4 HIV-1 replication in child versus adult cells was not caused by a differential expression of several known HIV-1 restriction factors. Similar levels of HIV DNA synthesis occurred in child cells infected with R5 and X4 viruses up to 48 hours after infection when R5 HIV-1 showed a significantly superior capacity to spread in culture than X4 virus. Cultured child cells well supported single round vescicular stomatitis virus-G pseudotyped virus replication, whereas superinfection of R5-infected cells with X4 HIV-1 (or vice versa) rescued the replication of this latter virus. Thus, child cells exposed to feeder cell culture represent a novel model system in which the superior capacity of R5 versus X4 viruses to spread can be investigated in primary, untransformed CD4(+) cells.

Young-onset colorectal cancer: treatment-related nausea, vomiting and diarrhoea.

OBJECTIVES: Early-onset colorectal cancer (EO-CRC) incidence is increasing, raising a clinical challenge. Clinicians tend to treat EO-CRC patients with more intensive regimens despite the lack of survival benefits, based on an age-related bias. Limited evidence is available regarding treatment-related toxicities in this peculiar subset of patients. METHODS: We performed a literature search in MEDLINE/PubMed, EMBASE and Scopus, looking for reporting of nausea, vomiting and diarrhoea occurring in patients with EO-CRC, defined by age lower than 50 years old at initial diagnosis, while receiving anticancer treatment. RESULTS: 2318 records were screened and 9 full-text articles were considered eligible for inclusion for a total of 59 783 patients (of whom 8681 EO-CRC patients). We found nausea and vomiting occurring at higher incidence among EO-CRC compared with older patients, while no difference was reported as for diarrhoea. Peritoneal involvement, age younger than 40, female gender, suboptimal adherence to guidelines and oxaliplatin might represent potential risk factors for increased nausea and vomiting in patients with EO-CRC. CONCLUSION: EO-CRC patients experience more nausea and vomiting but equal or less diarrhoea compared with older patients. Adherence to clinical guidelines is recommended, and more data are warranted to assess if an enhanced antiemetic approach might be required, particularly in case of specific risk factors.

The longitudinal characterization of immune responses in COVID-19 patients reveals novel prognostic signatures for disease severity, patients' survival and long COVID.

Introduction: SARS-CoV-2 pandemic still poses a significant burden on global health and economy, especially for symptoms persisting beyond the acute disease. COVID-19 manifests with various degrees of severity and the identification of early biomarkers capable of stratifying patient based on risk of progression could allow tailored treatments. Methods: We longitudinally analyzed 67 patients, classified according to a WHO ordinal scale as having Mild, Moderate, or Severe COVID-19. Peripheral blood samples were prospectively collected at hospital admission and during a 6-month follow-up after discharge. Several subsets and markers of the innate and adaptive immunity were monitored as putative factors associated with COVID-19 symptoms. Results: More than 50 immunological parameters were associated with disease severity. A decision tree including the main clinical, laboratory, and biological variables at admission identified low NK-cell precursors and CD14+CD91+ monocytes, and high CD8+ Effector Memory T cell frequencies as the most robust immunological correlates of COVID-19 severity and reduced survival. Moreover, low regulatory B-cell frequency at one month was associated with the susceptibility to develop long COVID at six months, likely due to their immunomodulatory ability. Discussion: These results highlight the profound perturbation of the immune response during COVID-19. The evaluation of specific innate and adaptive immune-cell subsets allows to distinguish between different acute and persistent COVID-19 symptoms.

Origin and evolution of SARS-CoV-2.

SARS-CoV-2 is a novel coronavirus that emerged in China at the end of 2019 causing the severe disease known as coronavirus disease 2019 (COVID-19). SARS-CoV-2, as to the previously highly pathogenic human coronaviruses named SARS-CoV, the etiological agent of severe acute respiratory syndrome (SARS), has a zoonotic origin, although SARS-CoV-2 precise chain of animal-to-human transmission remains undefined. Unlike the 2002-2003 pandemic caused by SARS-CoV whose extinction from the human population was achieved in eight months, SARS-CoV-2 has been spreading globally in an immunologically naïve population in an unprecedented manner. The efficient infection and replication of SARS-CoV-2 has resulted in the emergence of viral variants that have become predominant posing concerns about their containment as they are more infectious with variable pathogenicity in respect to the original virus. Although vaccine availability is limiting severe disease and death caused by SARS-CoV-2 infection, its extinction is far to be close and predictable. In this regard, the emersion of the Omicron viral variant in November 2021 was characterized by humoral immune escape and it has reinforced the importance of the global monitoring of SARS-CoV-2 evolution. Given the importance of the SARS-CoV-2 zoonotic origin, it will also be crucial to monitor the animal-human interface to be better prepared to cope with future infections of pandemic potential.

Circulating Tumor DNA to Drive Treatment in Metastatic Colorectal Cancer.

In the evolving molecular treatment landscape of metastatic colorectal cancer (mCRC), the identification of druggable alterations is pivotal to achieve the best therapeutic opportunity for each patient. Because the number of actionable targets is expanding, there is the need to timely detect their presence or emergence to guide the choice of different available treatment options. Liquid biopsy, through the analysis of circulating tumor DNA (ctDNA), has proven safe and effective as a complementary method to address cancer evolution while overcoming the limitations of tissue biopsy. Even though data are accumulating regarding the potential for ctDNA-guided treatments applied to targeted agents, still major gaps in knowledge exist as for their application to different areas of the continuum of care. In this review, we recapitulate how ctDNA information could be exploited to drive different targeted treatment strategies in mCRC patients, by refining molecular selection before treatment by addressing tumor heterogeneity beyond tumor tissue biopsy; longitudinally monitoring early-tumor response and resistance mechanisms to targeted agents, potentially leading to tailored, molecular-driven, therapeutic options; guiding the molecular triage towards rechallenge strategies with anti-EGFR agents, suggesting the best time for retreatment; and providing opportunities for an "enhanced rechallenge" through additional treatments or combos aimed at overcoming acquired resistance. Besides, we discuss future perspectives concerning the potential role of ctDNA to fine-tune investigational strategies such as immuno-oncology.

RAGE engagement by SARS-CoV-2 enables monocyte infection and underlies COVID-19 severity.

The spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has fueled the COVID-19 pandemic with its enduring medical and socioeconomic challenges because of subsequent waves and long-term consequences of great concern. Here, we chart the molecular basis of COVID-19 pathogenesis by analyzing patients' immune responses at single-cell resolution across disease course and severity. This approach confirms cell subpopulation-specific dysregulation in COVID-19 across disease course and severity and identifies a severity-associated activation of the receptor for advanced glycation endproducts (RAGE) pathway in monocytes. In vitro THP1-based experiments indicate that monocytes bind the SARS-CoV-2 S1-receptor binding domain (RBD) via RAGE, pointing to RAGE-Spike interaction enabling monocyte infection. Thus, our results demonstrate that RAGE is a functional receptor of SARS-CoV-2 contributing to COVID-19 severity.

The evolving panorama of HER2-targeted treatments in metastatic urothelial cancer: A systematic review and future perspectives.

PURPOSE: HER2 alterations are potential candidates for targeted treatments in metastatic urothelial/bladder cancer (mUC). ERBB2 gene amplification and mutations are found in around 6% and 4% of mUC, respectively. METHODS: This is a systematic review of clinical trials evaluating HER2-targeting (amplification and mutations) in mUC. We assigned each study to one of the following strategies: HER2-targeting with single agents, anti-HER2 agents in combination with cytotoxic chemotherapy, dual HER2 blockade, HER2-targeted antibody-drug conjugates (ADCs), and other novel therapeutic approaches. RESULTS: 36 clinical trials (17 with results and 19 ongoing) were included. As for ERBB2 amplification, anti-HER2 single agents (5 studies) and combinations with chemotherapy (4 studies) failed to provide any benefit, whereas dual HER2 blockade through monoclonal antibodies proved active in one trial in pretreated patients. Two studies assessed single-agent targeting for ERBB2 mutations with negative results. Most promising data come from 2 studies with ADCs in ERBB2 amplified tumors (disitamab-vedotin and trastuzumab-duocarmazine), while 2 other studies with TDM-1 and ADCT-502 was discontinued due to toxicity. In this category, trastuzumab-deruxtecan and other ADCs are still under investigation for either ERBB2-amplified or mutated mUC. Novel approaches include ADCs with immunotherapy (1 study with results), CAR-T cells, and HER2-sensitising vaccines. CONCLUSIONS: ERBB2 amplification could become a novel target in mUC, although the magnitude of clinical benefit remains to be clarified. To this regard, novel ADCs are the most promising strategy. ERBB2 mutations are still at very early stage of clinical study.

Impaired seroconversion after SARS-CoV-2 mRNA vaccines in patients with solid tumours receiving anticancer treatment.

BACKGROUND: Patients with solid tumours have high COVID-19 mortality. Limited and heterogeneous data are available regarding the immunogenicity of SARS-CoV-2 mRNA vaccines in this population. METHODS AND FINDINGS: This is a prospective, single-centre cohort study aiming at evaluating seroconversion in terms of anti-spike antibodies in a population of patients with solid tumours undergoing cancer therapy within 2 months before the second vaccine dose, as compared with a cohort of controls. Subjects who were not SARS-CoV-2 naïve were excluded, and 171 patients were included in the final study population (150 vaccinated with BNT162b2, 87.7%; 21 with mRNA-1273, 12.3%) and compared with 2406 controls. The median follow-up time from the second dose of vaccination was 30 days (12-42; IQR: 26-34). Most patients had metastatic disease (138, 80.7%). Seroconversion rate was significantly lower in cancer patients than in controls (94.2% versus 99.8%, p < 0.001). At univariate logistic regression analysis, Odds ratio (OR) for seroconversion was also reduced in older individuals (>70 years). A multivariate logistic model confirmed cancer as the only significant variable in impairing seroconversion (OR 0.03, p < 0.001). In the cancer population, a multivariate analysis among clinical variables, including the type of cancer treatment, showed ECOG PS > 2 as the only one of impact (OR 0.07, p = 0.012). CONCLUSIONS: There is a fraction of 6% of patients with solid tumours undergoing cancer treatment, mainly with poorer performance status, who fail to obtain seroconversion after SARS-CoV-2 mRNA vaccines. These patients should be considered for enhanced vaccination strategies and carefully monitored for SARS-CoV-2 infection during cancer treatment.

Biobanking for COVID-19 research.

BACKGROUND: Biobanks are imperative infrastructures, particularly during outbreaks, when there is an obligation to acquire and share knowledge as quick as possible to allow for implementation of science-based preventive, diagnostic, prognostic, and therapeutic strategies. METHODS: We established a COVID-19 biobank with the aim of collecting high-quality and well-annotated human biospecimens, in the effort to understand the pathogenic mechanisms underlying COVID-19 and identify therapeutic targets (COVID-BioB, NCT04318366). Here we describe our experience and briefly review the characteristics of the biobanks for COVID-19 that have been so far established. RESULTS: A total of 46,677 samples have been collected from 913 participants (63.3% males, median [IQR] age 62.2 [51.2-74.0] years) since the beginning of the program. Most patients (66.9%) had been admitted to hospital for COVID-19, with a median length of stay of 15.0 (9.0-27.0) days. A minority of patients (13.3% of the total) had been admitted for other reasons and subsequently tested positive for SARS-CoV-2. The remainder were managed at home after being seen at the Emergency Department. CONCLUSIONS: Having a solid research infrastructure already in place, along with flexibility and adaptability to new requirements, allowed for the quick building of a COVID-19 biobank that will help expand and share the knowledge of SARS-CoV-2.