We have unveiled a synthetic lethal interaction between K-
Ras oncogenes and
Cdk4 in a mouse tumor model that closely recapitulates human non-small cell lung carcinoma (NSCLC). Ablation of
Cdk4, but ...not
Cdk2 or
Cdk6, induces an immediate senescence response only in lung cells that express an endogenous K-
Ras oncogene. No such response occurs in lungs expressing a single
Cdk4 allele or in other K-
Ras-expressing tissues. More importantly, targeting
Cdk4 alleles in advanced tumors detectable by computed tomography scanning also induces senescence and prevents tumor progression. These observations suggest that robust and selective pharmacological inhibition of Cdk4 may provide therapeutic benefit for NSCLC patients carrying K-
RAS oncogenes.
► Ablation of
Cdk4 induces a senescence response in cells expressing a K-
Ras oncogene ► This synthetic lethal interaction is exquisitely specific for lung cells ► Loss of Cdk4 prevents progression of advanced CT+ lung adenocarcinomas ► A selective CDK4 inhibitor has significant therapeutic activity against these tumors
Mucopolysaccharidosis type IVA (MPSIVA) or Morquio A disease, a lysosomal storage disorder, is caused by N-acetylgalactosamine-6-sulfate sulfatase (GALNS) deficiency, resulting in keratan sulfate ...(KS) and chondroitin-6-sulfate accumulation. Patients develop severe skeletal dysplasia, early cartilage deterioration and life-threatening heart and tracheal complications. There is no cure and enzyme replacement therapy cannot correct skeletal abnormalities. Here, using CRISPR/Cas9 technology, we generate the first MPSIVA rat model recapitulating all skeletal and non-skeletal alterations experienced by patients. Treatment of MPSIVA rats with adeno-associated viral vector serotype 9 encoding Galns (AAV9-Galns) results in widespread transduction of bones, cartilage and peripheral tissues. This led to long-term (1 year) increase of GALNS activity and whole-body correction of KS levels, thus preventing body size reduction and severe alterations of bones, teeth, joints, trachea and heart. This study demonstrates the potential of AAV9-Galns gene therapy to correct the disabling MPSIVA pathology, providing strong rationale for future clinical translation to MPSIVA patients.
Prevalence of type 2 diabetes (T2D) and obesity is increasing worldwide. Currently available therapies are not suited for all patients in the heterogeneous obese/T2D population, hence the need for ...novel treatments. Fibroblast growth factor 21 (FGF21) is considered a promising therapeutic agent for T2D/obesity. Native FGF21 has, however, poor pharmacokinetic properties, making gene therapy an attractive strategy to achieve sustained circulating levels of this protein. Here, adeno‐associated viral vectors (AAV) were used to genetically engineer liver, adipose tissue, or skeletal muscle to secrete FGF21. Treatment of animals under long‐term high‐fat diet feeding or of ob/ob mice resulted in marked reductions in body weight, adipose tissue hypertrophy and inflammation, hepatic steatosis, inflammation and fibrosis, and insulin resistance for > 1 year. This therapeutic effect was achieved in the absence of side effects despite continuously elevated serum FGF21. Furthermore, FGF21 overproduction in healthy animals fed a standard diet prevented the increase in weight and insulin resistance associated with aging. Our study underscores the potential of FGF21 gene therapy to treat obesity, insulin resistance, and T2D.
Synopsis
This study describes the use of adeno‐associated viral (AAV) vectors to achieve long‐term production of fibroblast growth factor 21 (FGF21) to treat obesity and insulin resistance. AAV‐FGF21 gene transfer to healthy animals also prevented age‐associated weight gain and insulin resistance.
A one‐time administration of an AAV vector encoding FGF21 counteract obesity and insulin resistance for more than a year.
The approach works in two different animal models of obesity, induced either by diet or genetic mutations.
Administration of AAV‐FGF21 to healthy animals promotes healthy aging.
AAV‐FGF21 pharmacological effects are demonstrated after genetic engineering of 3 different tissues (liver, adipose tissue and skeletal muscle).
FGF21 gene therapy holds great translational potential in the fight against insulin resistance, T2D, obesity and related comorbidities.
This study describes the use of adeno‐associated viral (AAV) vectors to achieve long‐term production of fibroblast growth factor 21 (FGF21) to treat obesity and insulin resistance. AAV‐FGF21 gene transfer to healthy animals also prevented age‐associated weight gain and insulin resistance.
Senescent cells accumulate in multiple aging‐associated diseases, and eliminating these cells has recently emerged as a promising therapeutic approach. Here, we take advantage of the high lysosomal ...β‐galactosidase activity of senescent cells to design a drug delivery system based on the encapsulation of drugs with galacto‐oligosaccharides. We show that gal‐encapsulated fluorophores are preferentially released within senescent cells in mice. In a model of chemotherapy‐induced senescence, gal‐encapsulated cytotoxic drugs target senescent tumor cells and improve tumor xenograft regression in combination with palbociclib. Moreover, in a model of pulmonary fibrosis in mice, gal‐encapsulated cytotoxics target senescent cells, reducing collagen deposition and restoring pulmonary function. Finally, gal‐encapsulation reduces the toxic side effects of the cytotoxic drugs. Drug delivery into senescent cells opens new diagnostic and therapeutic applications for senescence‐associated disorders.
Synopsis
Senescent cells are present in many diseases where they play an active pathological role. A common feature of senescent cells is their high content of lysosomes. Here, it is reported a pharmacological vehicle with lysosomal tropism that preferentially releases drugs into senescent cells.
Drugs encapsulated with galacto‐oligosaccharides (gal‐encapsulation) are released into cells after digestion with lysosomal β‐galactosidase and this happens more efficiently in senescent cells.
After intravenous injection, gal‐encapsulated drugs preferentially deliver their cargo into pathological tissues with high content of senescent cells.
Gal‐encapsulated doxorubicin ameliorates lung fibrosis in mice, reducing collagen and recovering normal breathing, and this is in contrast to free doxorubicin.
When xenograft tumors in mice are treated with chemotherapy, a fraction of tumor cells undergo senescence, and concomitant treatment with gal‐encapsulated doxorubicin results in full tumor regression.
Gal‐encapsulation prevents the exposure of non‐pathological tissues to drugs and therefore reduces their associated toxicities, as it is shown for doxorubicin cardiotoxicity and for navitoclax‐induced thrombocytopenia.
Senescent cells are present in many diseases where they play an active pathological role. A common feature of senescent cells is their high content of lysosomes. Here, it is reported a pharmacological vehicle with lysosomal tropism that preferentially releases drugs into senescent cells.
Nanotechnology changed the concept of treatment for a variety of diseases, producing a huge impact regarding drug and gene delivery. Among the different targeted diseases, osteoporosis has ...devastating clinical and economic consequences. Since current osteoporosis treatments present several side effects, new treatment approaches are needed. Recently, the application of small interfering RNA (siRNA) has become a promising alternative. Wnt/β‐catenin signaling pathway controls bone development and formation. This pathway is negatively regulated by sclerostin, which knock‐down through siRNA application would potentially promote bone formation. However, the major bottleneck for siRNA‐based treatments is the necessity of a delivery vector, bringing nanotechnology as a potential solution. Among the available nanocarriers, mesoporous silica nanoparticles (MSNs) have attracted great attention for intracellular delivery of siRNAs. The mesoporous structure of MSNs permits the delivery of siRNAs together with another biomolecule, achieving a combination therapy. Here, the effectiveness of a new potential osteoporosis treatment based on MSNs is evaluated. The proposed system is effective in delivering SOST siRNA and osteostatin through systemic injection to bone tissue. The nanoparticle administration produced an increase expression of osteogenic related genes improving the bone microarchitecture. The treated osteoporotic mice recovered values of a healthy situation approaching to osteoporosis remission.
A mesoporous silica nanoparticles‐based system is designed for co‐delivering small interfering RNAs and an osteogenic peptide (osteostatin). The system is able to protect and deliver both biomolecules in the target tissue with promising results. It modifies gene expression and improves bone microarchitecture recovering healthy values. The application of nanoparticles can be considered a new potential alternative for osteoporosis remission.
Idiopathic pulmonary fibrosis (IPF) is a degenerative disease of the lungs with an average survival post-diagnosis of 2–3 years. New therapeutic targets and treatments are necessary. Mutations in ...components of the telomere-maintenance enzyme telomerase or in proteins important for telomere protection are found in both familial and sporadic IPF cases. However, the lack of mouse models that faithfully recapitulate the human disease has hampered new advances. Here, we generate two independent mouse models that develop IPF owing to either critically short telomeres (telomerase-deficient mice) or severe telomere dysfunction in the absence of telomere shortening (mice with Trf1 deletion in type II alveolar cells). We show that both mouse models develop pulmonary fibrosis through induction of telomere damage, thus providing proof of principle of the causal role of DNA damage stemming from dysfunctional telomeres in IPF development and identifying telomeres as promising targets for new treatments.
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•Trf1 deletion alone in alveolar type II cells induces pulmonary fibrosis in mice•Short telomeres and low-dose bleomycin induce pulmonary fibrosis in mice•These mouse models are instrumental for the development of new therapeutic strategies
Povedano et al. show that persistent telomeric damage induced by telomere dysfunction (either by shelterin disruption or by telomerase deficiency) triggers pulmonary fibrosis in mice. These mouse models are instrumental for the development of new therapeutic strategies to treat pulmonary fibrosis associated with telomere dysfunction.
Abstract
The mechanistic target of rapamycin complex 1 (mTORC1) integrates cellular nutrient signaling and hormonal cues to control metabolism. We have previously shown that constitutive nutrient ...signaling to mTORC1 by means of genetic activation of
RagA
(expression of GTP-locked RagA, or RagA
GTP
) in mice resulted in a fatal energetic crisis at birth. Herein, we rescue neonatal lethality in
RagA
GTP
mice and find morphometric and metabolic alterations that span glucose, lipid, ketone, bile acid and amino acid homeostasis in adults, and a median lifespan of nine months. Proteomic and metabolomic analyses of livers from
RagA
GTP
mice reveal a failed metabolic adaptation to fasting due to a global impairment in PPARα transcriptional program. These metabolic defects are partially recapitulated by restricting activation of RagA to hepatocytes, and revert by pharmacological inhibition of mTORC1. Constitutive hepatic nutrient signaling does not cause hepatocellular damage and carcinomas, unlike genetic activation of growth factor signaling upstream of mTORC1. In summary, RagA signaling dictates dynamic responses to feeding-fasting cycles to tune metabolism so as to match the nutritional state.
Aging in worms and flies is regulated by the PI3K/Akt/Foxo pathway. Here we extend this paradigm to mammals. Ptentg mice carrying additional genomic copies of Pten are protected from cancer and ...present a significant extension of life span that is independent of their lower cancer incidence. Interestingly, Ptentg mice have an increased energy expenditure and protection from metabolic pathologies. The brown adipose tissue (BAT) of Ptentg mice is hyperactive and presents high levels of the uncoupling protein Ucp1, which we show is a target of Foxo1. Importantly, a synthetic PI3K inhibitor also increases energy expenditure and hyperactivates the BAT in mice. These effects can be recapitulated in isolated brown adipocytes and, moreover, implants of Ptentg fibroblasts programmed with Prdm16 and Cebpβ form subcutaneous brown adipose pads more efficiently than wild-type fibroblasts. These observations uncover a role of Pten in promoting energy expenditure, thus decreasing nutrient storage and its associated damage.
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► A modest systemic increase in Pten activity extends longevity in mice ► Mice overexpressing Pten are protected from metabolic damage and cancer ► Pten positively regulates energy expenditure and brown adipose function ► Pharmacological PI3K inhibitors increase brown adipose activity
Five-year survival for pancreatic ductal adenocarcinoma (PDAC) patients remains below 7% due to the lack of effective treatments. Here, we report that combined ablation of EGFR and c-RAF expression ...results in complete regression of a significant percentage of PDAC tumors driven by Kras/Trp53 mutations in genetically engineered mice. Moreover, systemic elimination of these targets induces toxicities that are well tolerated. Response to this targeted therapy correlates with transcriptional profiles that resemble those observed in human PDACs. Finally, inhibition of EGFR and c-RAF expression effectively blocked tumor progression in nine independent patient-derived xenografts carrying KRAS and TP53 mutations. These results open the door to the development of targeted therapies for PDAC patients.
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•Combined Egfr/Raf1 ablation results in complete regression of a subset of PDACs•Mouse mutant Kras/Trp53-induced PDACs display distinct transcriptional profiles•PDAC transcriptional profiles determine their response to Egfr/Raf1 ablation•EGFR/c-RAF inhibition also prevents proliferation of PDX-derived tumor cells
Blasco et al. show that ablation of Egfr and Raf1 results in complete regression of a subset of mutant Kras/Trp53-induced pancreatic ductal adenocarcinomas (PDAC) without overt toxicity. Inhibition of EGFR and c-RAF expression also blocks the progression of patient-derived PDAC xenografts with mutant KRAS/TP53.
Although DNA damage is considered a driving force for aging, the nature of the damage that arises endogenously remains unclear. Replicative stress, a source of endogenous DNA damage, is prevented ...primarily by the ATR kinase. We have developed a mouse model of Seckel syndrome characterized by a severe deficiency in ATR. Seckel mice show high levels of replicative stress during embryogenesis, when proliferation is widespread, but this is reduced to marginal amounts in postnatal life. In spite of this decrease, adult Seckel mice show accelerated aging, which is further aggravated in the absence of p53. Together, these results support a model whereby replicative stress, particularly in utero, contributes to the onset of aging in postnatal life, and this is balanced by the replicative stress-limiting role of the checkpoint proteins ATR and p53.
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