The tumor suppressor Smad4 is involved in carcinogenesis mainly of the pancreas and colon. Functional inactivation of Smad4 is a genetically late event that occurs upon transition from premalignant ...stages to invasive and metastatic growth. Smad4 encodes an intracellular messenger common to all signalling cascades induced by members of the transforming growth factor-beta (TGF-beta) superfamily of cytokines. Despite extensive knowledge about the mechanisms of TGF-beta/Smad signal transduction, little is known about Smad4 targets involved in the transition to malignancy. The hallmark of invasive growth is a breakdown of the basement membrane (BM), a specialized sheet of extracellular matrix produced through cooperation of epithelial and stromal cells. Laminin-5, a heterotrimeric epithelial-derived BM component, is commonly lost in carcinomas but not in premalignant tumors. Herein, we report that in human colon and pancreatic tumor cells, Smad4 functions as a positive transcriptional regulator of all three genes encoding laminin-5. Coordinate re-expression of the three laminin-5 chains induced by reconstitution of Smad4 leads to secretion and deposition of the heterotrimeric molecule in BM-like structures. These data define the expression control of an essential BM component as a novel function for the tumor suppressor Smad4.
The tumor suppressor Smad4 is involved in carcinogenesis mainly of the pancreas and colon. Functional inactivation of Smad4 is a genetically late event that occurs upon transition from premalignant ...stages to invasive and metastatic growth. Smad4 encodes an intracellular messenger common to all signalling cascades induced by members of the transforming growth factor-beta (TGF- beta) superfamily of cytokines. Despite extensive knowledge about the mechanisms of TGF-beta/Smad signal transduction, little is known about Smad4 targets involved in the transition to malignancy. The hallmark of invasive growth is a breakdown of the basement membrane (BM), a specialized sheet of extracellular matrix produced through cooperation of epithelial and stromal cells. Laminin-5, a heterotrimeric epithelial-derived BM component, is commonly lost in carcinomas but not in premalignant tumors. Herein, we report that in human colon and pancreatic tumor cells, Smad4 functions as a positive transcriptional regulator of all three genes encoding laminin-5. Coordinate re- expression of the three laminin-5 chains induced by reconstitution of Smad4 leads to secretion and deposition of the heterotrimeric molecule in BM-like structures. These data define the expression control of an essential BM component as a novel function for the tumor suppressor Smad4.
Purpose
Fibroblast activation protein (FAP) is a membrane-bound protease that has limited expression in normal adult tissues but is highly expressed in the tumor microenvironment of many solid ...cancers. FAP-2286 is a FAP-binding peptide coupled to a radionuclide chelator that is currently being investigated in patients as an imaging and therapeutic agent. The potency, selectivity, and efficacy of FAP-2286 were evaluated in preclinical studies.
Methods
FAP expression analysis was performed by immunohistochemistry and autoradiography on primary human cancer specimens. FAP-2286 was assessed in biochemical and cellular assays and in
in vivo
imaging and efficacy studies, and was further evaluated against FAPI-46, a small molecule–based FAP-targeting agent.
Results
Immunohistochemistry confirmed elevated levels of FAP expression in multiple tumor types including pancreatic, breast, and sarcoma, which correlated with FAP binding by FAP-2286 autoradiography. FAP-2286 and its metal complexes demonstrated high affinity to FAP recombinant protein and cell surface FAP expressed on fibroblasts. Biodistribution studies in mice showed rapid and persistent uptake of
68
Ga-FAP-2286,
111
In-FAP-2286, and
177
Lu-FAP-2286 in FAP-positive tumors, with renal clearance and minimal uptake in normal tissues.
177
Lu-FAP-2286 exhibited antitumor activity in FAP-expressing HEK293 tumors and sarcoma patient-derived xenografts, with no significant weight loss. In addition, FAP-2286 maintained longer tumor retention and suppression in comparison to FAPI-46.
Conclusion
In preclinical models, radiolabeled FAP-2286 demonstrated high tumor uptake and retention, as well as potent efficacy in FAP-positive tumors. These results support clinical development of
68
Ga-FAP-2286 for imaging and
177
Lu-FAP-2286 for therapeutic use in a broad spectrum of FAP-positive tumors.
Purpose
FAP is a membrane-bound protease under investigation as a pan-cancer target, given its high levels in tumors but limited expression in normal tissues. FAP-2286 is a radiopharmaceutical in ...clinical development for solid tumors that consists of two functional elements: a FAP-targeting peptide and a chelator used to attach radioisotopes. Preclinically, we evaluated the immune modulation and anti-tumor efficacy of FAP-2287, a murine surrogate for FAP-2286, conjugated to the radionuclide lutetium-177 (
177
Lu) as a monotherapy and in combination with a PD-1 targeting antibody.
Methods
C57BL/6 mice bearing MCA205 mouse FAP-expressing tumors (MCA205-mFAP) were treated with
177
Lu-FAP-2287, anti-PD-1, or both. Tumor uptake of
177
Lu- FAP-2287 was assessed by SPECT/CT scanning, while therapeutic efficacy was measured by tumor volume and survival. Immune profiling of tumor infiltrates was evaluated through flow cytometry, RNA expression, and immunohistochemistry analyses.
Results
177
Lu-FAP-2287 rapidly accumulated in MCA205-mFAP tumors leading to significant tumor growth inhibition (TGI) and longer survival time. Significant TGI was also observed from anti-PD-1 and the combination. In flow cytometry analysis of tumors,
177
Lu-FAP-2287 increased CD8
+
T cell infiltration which was maintained in the combination with anti-PD-1. The increase in CD8
+
T cells was accompanied by an induction of STING-mediated type I interferon response and higher levels of co-stimulatory molecules such as CD86.
Conclusion
In a preclinical model, FAP-targeted radiotherapy enhanced anti-PD-1-mediated TGI by modulating the TME and increasing the recruitment of tumor-infiltrating CD8
+
T cells. These findings provide a rationale for clinical studies of combined
177
Lu-FAP-2286 radiotherapy and immune checkpoint inhibition in FAP-positive tumors.
Les Pseudomonas spp. phytobénéfiques sont des bactéries qui se développent principalement dans la rhizosphère, la zone du sol sous l’influence des racines. Elles sont capables d’inhiber le ...développement d’agent phytopathogènes et/ou de promouvoir directement la croissance des plantes. Ces bactéries représentent donc une alternative prometteuse aux pesticides et fertilisants souvent nuisibles pour l’environnement et/ou la santé humaine.Les travaux de recherche présentés dans cette thèse s’intéressent à la colonisation de la rhizosphère par ces bactéries bénéfiques En effet, leurs effets bénéfiques dépendent étroitement de leur capacité à coloniser la rhizosphère des plantes et à s’y maintenir. Les déterminants qui sous-tendent cette colonisation sont nombreux et interreliés, rendant ardues leur identification ainsi que l’évaluation de leur contribution dans ce processus complexe. Nous avons donc cherché à mieux comprendre ces déterminants, en nous intéressant à la fois aux déterminants bactériens (objectif 1 ) et aux déterminants végétaux (objectif 2) de la colonisation.Le premier objectif a consisté à évaluer la colonisation de la rhizosphère chez deux espèces végétales, Arabidopsis thaliana et Solanum tuberosum (la pomme de terre), par 60 souches de Pseudomonas spp. productrices de composés antibiotiques de la famille des phénazines. Nous avons également établi un portrait catabolique des souches étudiées. Les données récoltées ont été analysées à la lumière des génomes complets et annotés de ces souches, obtenus précédemment. Nous avons ainsi mis en évidence des liens entre des caractéristiques métaboliques, la présence de certains gènes et groupes de gènes, et les niveaux de colonisation de la rhizosphère. En particulier, la capacité à utiliser des composés azotés tels que des amines, ainsi que la présence de gènes liés à la biosynthèse de composés antimicrobiens, tels que le cyanure d’hydrogène, étaient associés à une meilleure colonisation. Un lien entre les différents sous-groupes taxonomiques des bactéries et leurs niveaux de colonisation a également été relevé. Les souches de P. chlororaphis colonisaient en moyenne davantage la rhizosphère des deux plantes que celles du sousgroupe P. fluorescens. Le second objectif visait les déterminants végétaux de la colonisation de la rhizosphère, qui sont souvent peu explorés. Il a été étudié à l’aide de 20 mutants monogéniques d’A thaliana inoculés avec deux souches de P. chlororaphis subsp. piscium aux capacités de colonisation différentes : une bonne colonisatrice, DTR133, et une moins bonne colonisatrice, ToZa7. Les gènes mutés ont été choisis pour leur rôle dans l’exsudation racinaire, l’immunité ou l’architecture du système racinaire, qui sont susceptibles d’affecter directement la colonisation bactérienne. Les résultats montrent une influence de certaines mutations liées à l’architecture racinaire, qui concernent les gènes smb et shv3. Par ailleurs, l’inoculation de certains mutants a entraîné une augmentation de la masse des parties aériennes par rapport aux mutants non-inoculés, alors qu’aucune variation de masse n’a été observée chez les plantes sauvages. Ces mutations affectaient notamment le système racinaire, mais aussi les phytohormones. Ces résultats indiquent une interaction entre le génotype de la plante, sa croissance et la colonisation de la rhizosphère.Ces travaux de recherche ont permis d’identifier de nombreux gènes bactériens et végétaux potentiellement impliqués dans la colonisation de la rhizosphère. Des liens entre la colonisation et certaines voies métaboliques bactériennes ont également été mis en évidence. Ces résultats ouvrent la voie à de multiples perspectives de recherche. Ils contribueront à la sélection et au développement de biopesticides et biofertilisants, favorisant une agriculture plus résiliente et plus respectueuse de la santé des écosystèmes dans un monde instable au climat changeant.
Dysfunctions of auditory-verbal declarative and working memory are observed in patients with depressive disorders (DD). The authors wanted to see, whether antidepressive therapy improved the ...efficiency of cognitive processes among patients suffering from DD and determine possible associations between auditory-verbal declarative and working memory performance, evaluated before treatment vs. remission degree after treatment.
The study was carried out in 87 subjects, patients with depressive disorders (n=30, DD) and healthy subjects (n=57, CG, control group). The AVLT (Auditory Verbal Learning Test) and the Stroop Test were used.
CG obtained higher results vs. DD-I (the evaluation started on the therapy onset) in the Stroop Test-RCNb (Reading Colour Names in Black)/time, NCWd (Naming Colour of Word – Different)/time, NCWd/errors, AVLT: the number of words after 30 minutes. CG demonstrated higher results than DD-II (following eight weeks of pharmacological treatment) in RCNb/time, NCWd/time, AVLT: the number of words in the first trial, the number of words after 30 minutes. Compared to DD-I, DD-II achieved better results in NCWd/errors. No statistically significant differences were observed in both tests between the patients with remission and without remission. Statistical analysis revealed the lack of significant dependences among HDRS after treatment and cognitive functions before treatment.
Depressive disorders are associated with deteriorated efficiency of auditory-verbal declarative and working memory. No improvement was observed in the efficiency of auditory-verbal declarative or working memory after 8-week therapy. The performance level of cognitive processes before pharmacotherapy has no effect on the intensity of depression symptoms after therapy.
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