306 research outputs found
Antibody-mediated blockade of JMJD6 interaction with collagen I exerts antifibrotic and antimetastatic activities
JMJD6 is known to localize in the nucleus, exerting histone arginine demethylase and lysyl hydroxylase activities. A novel localization of JMJD6 in the extracellular matrix, resulting from its secretion as a soluble protein, was unveiled by a new anti-JMJD6 mAb called P4E11, which was developed to identify new targets in the stroma. Recombinant JMJD6 binds with collagen type I (Coll-I), and distinct JMJD6 peptides interfere with collagen fibrillogenesis, collagen-fibronectin interaction, and adhesion of human tumor cells to the collagen substrate. P4E11 and collagen binding to JMJD6 are mutually exclusive because the amino acid sequences of JMJD6 necessary for the interaction with Coll-I are part of the conformational epitope recognized by P4E11. In mice injected with mouse 4T1 breast carcinoma cells, treatment with P4E11 reduced fibrosis at the primary tumor and prevented lung metastases. Reduction of fibrosis has also been documented in human breast and ovarian tumors (MDA-MB-231 and IGROV1, respectively) xenotransplanted into immunodeficient mice treated with P4E11. In summary, this study uncovers a new localization and function for JMJD6 that is most likely independent from its canonical enzymatic activities, and demonstrates that JMJD6 can functionally interact with Coll-I. P4E11 mAb, inhibiting JMJD6/Coll-I interaction, represents a new opportunity to target fibrotic and tumor diseases
Taxanes enhance trastuzumab-mediated ADCC on tumor cells through NKG2D-mediated NK cell recognition
Recent clinical data indicate a synergistic therapeutic effect between trastuzumab and taxanes in neoadjuvantly treated HER2-positive breast cancer (BC) patients. In HER2+ BC experimental models and patients, we investigated whether this synergy depends on the ability of drug-induced stress to improve NK cell effectiveness and thus trastuzumab-mediated ADCC. HER2+ BC cell lines BT474 and MDAMB361 treated with docetaxel showed up-modulation of NK activator ligands both in vitro and in vivo, accompanied by a 15-40% increase in in vitro trastuzumab-mediated ADCC; antibodies blocking the NKG2D receptor significantly reduced this enhancement. NKG2D receptor expression was increased by docetaxel treatment in circulating and splenic NK cells from mice xenografted with tumor cells, an increase related to expansion of the CD11b+Ly6G+ cell population. Accordingly, NK cells derived from HER2+ BC patients after treatment with taxane-containing therapy expressed higher levels of NKG2D receptor than before treatment. Moreover, plasma obtained from these patients recapitulated the modulation of NKG2D on healthy donors' NK cells, improving their trastuzumab-mediated activity in vitro. This enhancement occurred mainly using plasma from patients with low NKG2D basal expression. Our results indicate that taxanes increase tumor susceptibility to ADCC by acting on tumor and NK cells, and suggest that taxanes concomitantly administered with trastuzumab could maximize the antibody effect, especially in patients with low basal immune effector cytotoxic activit
Modulation of DNA repair genes induced by TLR9 agonists: A strategy to eliminate “altered” cells?
We provided evidence that the TLR9 engagement of innate immune cells present in the tumor microenvironment by CpG-oligodeoxynucleotide (CpG-ODN) induces down-modulation of DNA repair gene expression in tumor cells, sensitizing cancer cells to DNA-damaging chemotherapy. These findings expand the benefits of CpG-ODN therapy beyond induction of a strong immune response
Worldwide SARS-CoV-2 haplotype distribution in early pandemic
The world is experiencing one of the most severe viral outbreaks in the last few years, the pandemic infection by SARS-CoV-2, the causative agent of COVID-19 disease. As of December 10th 2021, the virus has spread worldwide, with a total number of more than 267 million of confirmed cases (four times more in the last year), and more than 5 million deaths. A great effort has been undertaken to molecularly characterize the virus, track the spreading of different variants across the globe with the aim to understand the potential effects in terms of transmission capability and different fatality rates. Here we focus on the genomic diversity and distribution of the virus in the early stages of the pandemic, to better characterize the origin of COVID-19 and to define the geographical and temporal evolution of genetic clades. By performing a comparative analysis of 75401 SARS-CoV-2 reported sequences (as of December 2020), using as reference the first viral sequence reported in Wuhan in December 2019, we described the existence of 26538 genetic variants, the most frequent clustering into four major clades characterized by a specific geographical distribution. Notably, we found the most frequent variant, the previously reported missense p.Asp614Gly in the S protein, as a single mutation in only three patients, whereas in the large majority of cases it occurs in concomitance with three other variants, suggesting a high linkage and that this variant alone might not provide a significant selective advantage to the virus. Moreover, we evaluated the presence and the distribution in our dataset of the mutations characterizing the so called "british variant", identified at the beginning of 2021, and observed that 9 out of 17 are present only in few sequences, but never in linkage with each other, suggesting a synergistic effect in this new viral strain. In summary, this is a large-scale analysis of SARS-CoV-2 deposited sequences, with a particular focus on the geographical and temporal evolution of genetic clades in the early phase of COVID-19 pandemic
The Link Between the Microbiota and HER2+ Breast Cancer: The New Challenge of Precision Medicine
The microbiota is emerging as a key player in cancer due to its involvement in several host physiological functions, including digestion, development of the immune system, and modulation of endocrine function. Moreover, its participation in the efficacy of anticancer treatments has been well described. For instance, the involvement of the breast microbiota in breast cancer (BC) development and progression has gained ground in the past several years. In this review, we report and discuss new findings on the impact of the gut and breast microbiota on BC, focusing on the HER2+ BC subtype, and the possibility of defining microbial signatures that are associated with disease aggressiveness, treatment response, and therapy toxicity. We also discuss novel insights into the mechanisms through which microorganism-host interactions occur and the possibility of microbiota editing in the prevention and treatment optimization of BC
HER2 isoforms co-expression differently tunes mammary tumor phenotypes affecting onset, vasculature and therapeutic response
Full-length HER2 oncoprotein and splice variant Delta16 are co-expressed in
human breast cancer. We studied their interaction in hybrid transgenic mice bearing
human full-length HER2 and Delta16 (F1 HER2/Delta16) in comparison to parental
HER2 and Delta16 transgenic mice. Mammary carcinomas onset was faster in F1
HER2/Delta16 and Delta16 than in HER2 mice, however tumor growth was slower,
and metastatic spread was comparable in all transgenic mice. Full-length HER2
tumors contained few large vessels or vascular lacunae, whereas Delta16 tumors
presented a more regular vascularization with numerous endothelium-lined small
vessels. Delta16-expressing tumors showed a higher accumulation of i.v. injected
doxorubicin than tumors expressing full-length HER2. F1 HER2/Delta16 tumors with
high full-length HER2 expression made few large vessels, whereas tumors with low
full-length HER2 and high Delta16 contained numerous small vessels and expressed
higher levels of VEGF and VEGFR2. Trastuzumab strongly inhibited tumor onset in
F1 HER2/Delta16 and Delta16 mice, but not in full-length HER2 mice. Addiction of
F1 tumors to Delta16 was also shown by long-term stability of Delta16 levels during
serial transplants, in contrast full-length HER2 levels underwent wide fluctuations.
In conclusion, full-length HER2 leads to a faster tumor growth and to an irregular
vascularization, whereas Delta16 leads to a faster tumor onset, with more regular
vessels, which in turn could better transport cytotoxic drugs within the tumor, and to
a higher sensitivity to targeted therapeutic agents. F1 HER2/Delta16 mice are a new
immunocompetent mouse model, complementary to patient-derived xenografts, for
studies of mammary carcinoma onset, prevention and therapy
Biofilm formation by the host microbiota: a protective shield against immunity and its implication in cancer
Human-resident microbes typically cluster into biofilms - structurally organized communities embedded within a matrix of self-produced extracellular polymeric substance (EPS) that serves as a protective shield. These biofilms enhance microbial survival and functional adaptability, favoring a symbiotic relationship with the host under physiological conditions. However, biofilms exhibit a dual role in modulating the immune response. If their ability to promote tolerance is key to safeguarding homeostasis, by contrast, their persistence can overcome the cutting-edge balance resulting in immune evasion, chronic inflammation and development of numerous diseases such as cancer. Recent evidence highlights the significance of cancer-associated microbiota in shaping the tumor microenvironment (TME). These microbial inhabitants often exhibit biofilm-like structures, which may protect them from host immune responses and therapeutic interventions. The presence of biofilm-forming microbiota within the TME may promote chronic inflammation, and release of bioactive molecules that interfere with immune surveillance mechanisms, thereby enabling cancer cells to evade immune destruction. This review delves into the complex interplay between biofilms and cancer, with particular focus on the tumor-associated microbiota and the implications of biofilm involvement in modulating the immune landscape of the TME. Addressing this intricate relationship holds promises for innovative therapeutic approaches aimed at reprogramming the microbiota-cancer axis for better clinical outcomes
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