A nanoengineered topical transmucosal cisplatin delivery system induces anti-tumor response in animal models and patients with oral cancer.

Despite therapeutic advancements, oral cavity squamous cell carcinoma (OCSCC) remains a difficult disease to treat. Systemic platinum-based chemotherapy often leads to dose-limiting toxicity (DLT), affecting quality of life. PRV111 is a nanotechnology-based system for local delivery of cisplatin loaded chitosan particles, that penetrate tumor tissue and lymphatic channels while avoiding systemic circulation and toxicity. Here we evaluate PRV111 using animal models of oral cancer, followed by a clinical trial in patients with OCSCC. In vivo, PRV111 results in elevated cisplatin retention in tumors and negligible systemic levels, compared to the intravenous, intraperitoneal or intratumoral delivery. Furthermore, PRV111 produces robust anti-tumor responses in subcutaneous and orthotopic cancer models and results in complete regression of carcinogen-induced premalignant lesions. In a phase 1/2, open-label, single-arm trial (NCT03502148), primary endpoints of efficacy (≥30% tumor volume reduction) and safety (incidence of DLTs) of neoadjuvant PRV111 were reached, with 69% tumor reduction in ~7 days and over 87% response rate. Secondary endpoints (cisplatin biodistribution, loco-regional control, and technical success) were achieved. No DLTs or drug-related serious adverse events were reported. No locoregional recurrences were evident in 6 months. Integration of PRV111 with current standard of care may improve health outcomes and survival of patients with OCSCC.

TET2 controls chemoresistant slow-cycling cancer cell survival and tumor recurrence.

Dormant or slow-cycling tumor cells can form a residual chemoresistant reservoir responsible for relapse in patients, years after curative surgery and adjuvant therapy. We have adapted the pulse-chase expression of H2BeGFP for labeling and isolating slow-cycling cancer cells (SCCCs). SCCCs showed cancer initiation potential and enhanced chemoresistance. Cells at this slow-cycling status presented a distinctive nongenetic and cell-autonomous gene expression profile shared across different tumor types. We identified TET2 epigenetic enzyme as a key factor controlling SCCC numbers, survival, and tumor recurrence. 5-Hydroxymethylcytosine (5hmC), generated by TET2 enzymatic activity, labeled the SCCC genome in carcinomas and was a predictive biomarker of relapse and survival in cancer patients. We have shown the enhanced chemoresistance of SCCCs and revealed 5hmC as a biomarker for their clinical identification and TET2 as a potential drug target for SCCC elimination that could extend patients' survival.

Docetaxel-loaded polyglutamic acid-PEG nanocapsules for the treatment of metastatic cancer.

The design of nanomedicines with suitable physicochemical characteristics for the lymphatic targeting of drugs is critical in order to reach the lymph nodes, where metastatic cells often accumulate. Based on the known effect of particle size and surface hydrophilicity on the capacity of nanocarriers to reach the lymph nodes, here we report the formation and characterization of 100nm polyglutamic acid-polyethylene glycol (PGA-PEG) nanocapsules together with the assessment of their potential for the treatment of cancer with lymphatic metastatic spread. To this purpose, we first studied the biodistribution of fluorescently labeled PGA-PEG nanocapsules (100nm), following, either intravenous or subcutaneous administration. The results confirmed the accumulation of nanocapsules in the lymphatic system, especially upon subcutaneous administration. Next, we evaluated the efficacy and toxicity of the docetaxel-loaded nanocapsules in an orthotopic lung cancer model that metastasizes to the lymph nodes. As expected from the rational design, DCX-loaded PGA-PEG nanocapsules exhibited a greatly enhanced antitumoral efficacy and a reduced toxicity when compared with the commercial formulation Taxotere®. Furthermore, the administration of DCX-loaded PGA-PEG nanocapsules resulted in the practical elimination of the metastatic load in the mediastinal lymph nodes, whereas the treatment with the commercial formulation had a minor effect. Overall, these findings underscore the potential of PGA-PEG nanocapsules for the delivery of anticancer drugs to both, the tumor tissue and the metastatic lymph nodes. Therefore, they represent a promising therapy for the treatment of lung metastatic cancer.

Transcriptional repression of Bmp2 by p21(Waf1/Cip1) links quiescence to neural stem cell maintenance.

Relative quiescence and self renewal are defining features of adult stem cells, but their potential coordination remains unclear. Subependymal neural stem cells (NSCs) lacking cyclin-dependent kinase (CDK) inhibitor (CKI) 1a (p21) exhibit rapid expansion that is followed by their permanent loss later in life. Here we demonstrate that transcription of the gene encoding bone morphogenetic protein 2 (Bmp2) in NSCs is under the direct negative control of p21 through actions that are independent of CDK. Loss of p21 in NSCs results in increased levels of secreted BMP2, which induce premature terminal differentiation of multipotent NSCs into mature non-neurogenic astrocytes in an autocrine and/or paracrine manner. We also show that the cell-nonautonomous p21-null phenotype is modulated by the Noggin-rich environment of the subependymal niche. The dual function that we describe here provides a physiological example of combined cell-autonomous and cell-nonautonomous functions of p21 with implications in self renewal, linking the relative quiescence of adult stem cells to their longevity and potentiality.

SUMOylation of p53 mediates interferon activities.

There is growing evidence that many host proteins involved in innate and intrinsic immunity are regulated by SUMOylation, and that SUMO contributes to the regulatory process that governs the initiation of the type I interferon (IFN) response. The tumor suppressor p53 is a modulator of the IFN response that plays a role in virus-induced apoptosis and in IFN-induced senescence. Here we demonstrate that IFN treatment increases the levels of SUMOylated p53 and induces cellular senescence through a process that is partially dependent upon SUMOylation of p53. Similarly, we show that vesicular stomatitis virus (VSV) infection induces p53 SUMOylation, and that this modification favors the control of VSV replication. Thus, our study provides evidence that IFN signaling induces p53 SUMOylation, which results in the activation of a cellular senescence program and contributes to the antiviral functions of interferon.