Bladder cancer is lethal in its advanced, muscle-invasive phase with very limited therapeutic advances
. Recent molecular characterization has defined new (epi)genetic drivers and potential targets ...for bladder cancer
. The immune checkpoint inhibitors have shown remarkable efficacy but only in a limited fraction of bladder cancer patients
. Here, we show that high G9a (EHMT2) expression is associated with poor clinical outcome in bladder cancer and that targeting G9a/DNMT methyltransferase activity with a novel inhibitor (CM-272) induces apoptosis and immunogenic cell death. Using an immunocompetent quadruple-knockout (Pten
; Trp53
; Rb1
; Rbl1
) transgenic mouse model of aggressive metastatic, muscle-invasive bladder cancer, we demonstrate that CM-272 + cisplatin treatment results in statistically significant regression of established tumors and metastases. The antitumor effect is significantly improved when CM-272 is combined with anti-programmed cell death ligand 1, even in the absence of cisplatin. These effects are associated with an endogenous antitumor immune response and immunogenic cell death with the conversion of a cold immune tumor into a hot tumor. Finally, increased G9a expression was associated with resistance to programmed cell death protein 1 inhibition in a cohort of patients with bladder cancer. In summary, these findings support new and promising opportunities for the treatment of bladder cancer using a combination of epigenetic inhibitors and immune checkpoint blockade.
The activation of the Hippo pathway effector Yes-associated protein (YAP) is modulated by different upstream cues. Phosphorylated YAP accumulates in the cytosol where it is targeted for degradation. ...In its active form, YAP translocates to the nucleus and acts as a transcriptional co-activator, binding to different transcription factors such as the TEA-domain transcription factor family (TEADs) to activate the transcription of tumour promoting genes. In the context of head and neck cancer, YAP activation is associated to malignant transformation, poor overall survival and disease free survival, resistance to chemotherapy and radiotherapy, and potential resistance to immunotherapy.
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•The Hippo-YAP is a relevant oncogenic signalling pathway in HNSCC.•YAP is a transcriptional co-activator of genes involved in growth and tumorigenesis.•YAP associates with poor prognosis and resistance to chemo and radiotherapy.•Hippo-YAP pathway components are novel druggable targets in HNSCC.
The Hippo-YAP (Yes-associated protein) pathway is a key regulator of tissue growth, organ size and stem cell function. More recently, a fundamental role for this pathway has emerged in stem cell function and tumorigenesis. Activation of the transcriptional co-activator YAP promotes cell-contact independent proliferation, epithelial to mesenchymal transition (EMT), cancer stem cell features and drug resistance. In this review, we describe the main components of the pathway, the microenvironment and the cell-intrinsic cues governing its activation, the downstream players of the pathway and the biological implications of their activation in the context of cancer. We will focus on the existing knowledge of this pathway in head and neck squamous carcinoma (HNSCC), its clinical value in this type of cancer as a marker of poor prognosis and resistance to therapy, as well as the most encouraging therapeutic strategies targeting the pathway.
Bladder cancer is a clinical and social problem due to its high incidence and recurrence rates. It frequently appears in elderly patients showing other medical comorbidities that hamper the use of ...standard chemotherapy. We evaluated the activity of CDK4/6 inhibitor as a new therapy for patients unfit for cisplatin (CDDP).
Bladder cancer cell lines were tested for
sensitivity to CDK4/6 inhibition. A novel metastatic bladder cancer mouse model was developed and used to test its
activity.
Cell lines tested were sensitive to CDK4/6 inhibition, independent on
gene status. Transcriptome analyses and knockdown experiments revealed a major role for FOXM1 in this response. CDK4/6 inhibition resulted in reduced FOXM1 phosphorylation
and
and showed synergy with CDDP, allowing a significant tumor regression. FOXM1 exerted important oncogenic roles in bladder cancer.
CDK4/6 inhibitors, alone or in combination, are a novel therapeutic strategy for patients with advanced bladder cancer previously classified as unfit for current treatment options.
Abstract
Regenerative proliferation capacity and poor differentiation are histological features usually linked to poor prognosis in head and neck squamous cell carcinoma (hnSCC). However, the ...pathways that regulate them remain ill-characterized. Here, we show that those traits can be triggered by the RHO GTPase activator VAV2 in keratinocytes present in the skin and oral mucosa. VAV2 is also required to maintain those traits in hnSCC patient-derived cells. This function, which is both catalysis- and RHO GTPase-dependent, is mediated by c-Myc- and YAP/TAZ-dependent transcriptomal programs associated with regenerative proliferation and cell undifferentiation, respectively. High levels of
VAV2
transcripts and VAV2-regulated gene signatures are both associated with poor hnSCC patient prognosis. These results unveil a druggable pathway linked to the malignancy of specific SCC subtypes.
Fanconi anemia (FA) patients display an exacerbated risk of oral squamous cell carcinoma (OSCC) and oral potentially malignant lesions (OPMLs) at early ages. As patients have defects in their DNA ...repair mechanisms, standard-of-care treatments for OSCC such as radiotherapy and chemotherapy, give rise to severe toxicities. New methods for early diagnosis are urgently needed to allow for treatment in early disease stages and achieve better clinical outcomes. We conducted a prospective, longitudinal study wherein liquid biopsies from sixteen patients with no clinical diagnoses of OPML and/or OSCC were analyzed for the presence of mutations in cancer genes. The DNA from saliva and plasma were sequentially collected and deep-sequenced, and the clinical evaluation followed over a median time of approximately 2 years. In 9/16 FA patients, we detected mutations in cancer genes (mainly
) with minor allele frequencies (MAF) of down to 0.07%. Importantly, all patients that had mutations and clinical follow-up data after mutation detection (
= 6) developed oral precursor lesions or OSCC. The lead-time between mutation detection and tumor diagnosis ranged from 23 to 630 days. Strikingly, FA patients without mutations displayed a significantly lower risk of developing precursor lesions or OSCCs. Therefore, our diagnostic approach could help to stratify FA patients into risk groups, which would allow for closer surveillance for OSCCs or precursor lesions.
Head and neck squamous cell carcinoma (HNSCC) is the sixth most common cancer worldwide, and although new therapeutic approaches have been recently evaluated, overall patient survival is still poor. ...Thus, new effective and selective clinical treatments are urgently needed. An analysis of data from large-scale, high-throughput drug screening cell line projects identified Bosutinib, a Src/Abl inhibitor that is currently used for the treatment of chronic myelogenous leukemia, as a candidate drug to treat HNSCC. Using a panel of HNSCC-derived cell lines, we found that treatment with Bosutinib reduced cell proliferation and induced apoptosis of sensitive cell lines. The drug rapidly inhibited Src and EGFR (epidermal growth factor receptor) phosphorylation, and sensitivity to Bosutinib was correlated with the activation status of EGFR. Similar findings were observed in in vivo xenograft assays using HNSCC derived cells. Moreover, in the presence of mutations in
, the combination of Bosutinib with the PI3Kα inhibitor Alpelisib showed a synergistic effect. These results suggest that Bosutinib could be a new effective drug for the treatment of HNSCC, particularly in tumors with high EGFR activity. Its combination with Alpelisib could especially benefit patients bearing activating mutations of
.
Background
Head and neck squamous cell carcinoma (SCC) is one of the most prevalent and deadly cancers worldwide. Even though surgical approaches, radiation therapy, and therapeutic agents are ...commonly used, the prognosis of this cancer remains poor, with a tendency towards recurrence and metastasis. Current targeted therapeutic options for these patients are limited to monoclonal antibodies against EGFR or PD-1 receptors. Thus, there is an urgent need to introduce new molecularly targeted therapies for treating head and neck SCC. EGFR can be used as a target to improve the ability of nanoparticles to bind to tumor cells and deliver chemotherapeutic agents. In fact, over 90% of head and neck SCCs overexpress EGFR, and other tumor types, such as colorectal and glioblastoma, show EGFR overexpression. The PI3K/mTOR signaling pathway is one of the most commonly altered oncogenic pathways in head and neck SCC. Alpelisib is a specific PI3Kα inhibitor indicated for PIK3CA mutant advanced breast cancer that showed promising activity in clinical trials in head and neck SCC. However, its use is associated with dose-limiting toxicities and treatment-related adverse effects.
Results
We generated polylactide (PLA) polymeric nanoparticles conjugated to anti-EGFR antibodies via chemical cross-linking to a polyethyleneimine (PEI) coating. Antibody-conjugated nanoparticles (ACNP) displayed low polydispersity and high stability. In vivo, ACNP showed increased tropism for EGFR-expressing head and neck tumors in a xenograft model compared to non-conjugated nanoparticles (NP). Alpelisib-loaded nanoparticles were homogeneous, stable, and showed a sustained drug release profile. Encapsulated Alpelisib inhibited PI3K pathway activation in the different cell lines tested that included wild type and altered PIK3CA. Alpelisib-NP and Alpelisib-ACNP decreased by 25 times the half-maximal inhibitory concentration compared to the free drug and increased the bioavailability of the drug in the cells. Herein we propose an efficient strategy to treat head and neck SCC based on nanotechnology.
Conclusions
Anti-EGFR-conjugated polymeric nanoparticles are an effective delivery system to increase drug efficiency and bioavailability in head and neck cancer cells. This strategy can help reduce drug exposure in disease-free organs and decrease drug-associated unwanted side effects.
IKKβ (encoded by
) is a protein kinase that regulates the activity of numerous proteins important in several signaling pathways, such as the NF-κB pathway. IKKβ exerts a protumorigenic role in ...several animal models of lung, hepatic, intestinal, and oral cancer. In addition, genomic and proteomic studies of human tumors also indicate that
gene is amplified or overexpressed in multiple tumor types. Here, the relevance of IKKβ in skin cancer was determined by performing carcinogenesis studies in animal models overexpressing IKKβ in the basal skin layer. IKKβ overexpression resulted in a striking resistance to skin cancer development and an increased expression of several tumor suppressor proteins, such as p53, p16, and p19. Mechanistically, this skin tumor-protective role of IKKβ is independent of p53, but dependent on the activity of the
locus. Interestingly, in the absence of p16 and p19, IKKβ-increased expression favors the appearance of cutaneous spindle cell-like squamous cell carcinomas, which are highly aggressive tumors. These results reveal that IKKβ activity prevents skin tumor development, and shed light on the complex nature of IKKβ effects on cancer progression, as IKKβ can both promote and prevent carcinogenesis depending on the cell type or molecular context.
The ability of IKKβ to promote or prevent carcinogenesis suggests the need for further evaluation when targeting this protein.
.
Prior reports showed the critical requirement of Sos1 for epithelial carcinogenesis, but the specific functionalities of the homologous Sos1 and Sos2 GEFs in skin homeostasis and tumorigenesis remain ...unclear. Here, we characterize specific mechanistic roles played by Sos1 or Sos2 in primary mouse keratinocytes (a prevalent skin cell lineage) under different experimental conditions. Functional analyses of actively growing primary keratinocytes of relevant genotypes-WT, Sos1-KO, Sos2-KO, and Sos1/2-DKO-revealed a prevalent role of Sos1 regarding transcriptional regulation and control of RAS activation and mechanistic overlapping of Sos1 and Sos2 regarding cell proliferation and survival, with dominant contribution of Sos1 to the RAS-ERK axis and Sos2 to the RAS-PI3K/AKT axis. Sos1/2-DKO keratinocytes could not grow under 3D culture conditions, but single Sos1-KO and Sos2-KO keratinocytes were able to form pseudoepidermis structures that showed disorganized layer structure, reduced proliferation, and increased apoptosis in comparison with WT 3D cultures. Remarkably, analysis of the skin of both newborn and adult Sos2-KO mice uncovered a significant reduction of the population of stem cells located in hair follicles. These data confirm that Sos1 and Sos2 play specific, cell-autonomous functions in primary keratinocytes and reveal a novel, essential role of Sos2 in control of epidermal stem cell homeostasis.
Fanconi anemia (FA) patients have an exacerbated risk of head and neck squamous cell carcinoma (HNSCC). Treatment is challenging as FA patients display enhanced toxicity to standard treatments, ...including radio/chemotherapy. Therefore, better therapies as well as new disease models are urgently needed. We have used CRISPR/Cas9 editing tools in order to interrupt the human
gene by the generation of insertions/deletions (indels) in exon 4 in two cancer cell lines from sporadic HNSCC having no mutation in FA-genes: CAL27 and CAL33 cells. Our approach allowed efficient editing, subsequent purification of single-cell clones, and Sanger sequencing validation at the edited locus. Clones having frameshift indels in homozygosis did not express FANCA protein and were selected for further analysis. When compared with parental CAL27 and CAL33,
-mutant cell clones displayed a FA-phenotype as they (i) are highly sensitive to DNA interstrand crosslink (ICL) agents such as mitomycin C (MMC) or cisplatin, (ii) do not monoubiquitinate FANCD2 upon MMC treatment and therefore (iii) do not form FANCD2 nuclear foci, and (iv) they display increased chromosome fragility and G2 arrest after diepoxybutane (DEB) treatment. These
-mutant clones display similar growth rates as their parental cells. Interestingly, mutant cells acquire phenotypes associated with more aggressive disease, such as increased migration in wound healing assays. Therefore, CAL27 and CAL33 cells with
mutations are phenocopies of FA-HNSCC cells.
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