Pancreatic cancer reveals the worst prognosis among human cancers with little improvement in its clinical outcome in the last three decades. We previously suggested that polypeptide N-acetylgalactosaminyltransferase 6 (GALNT6), which catalyzes O-type glycosylation of Mucin 1, might be a promising molecular target for drug development for breast cancer. In this study, we report upregulation of GALNT6 in pancreatic cancer cells where Mucin proteins are highly O-glycosylated. We found that knockdown of GALNT6 with small interfering RNA in pancreatic cancer cells decreased the amount of Mucin 4 protein as well as that of its transcript, reduced the levels of human epidermal growth factor receptor 2 and extracellular signal-regulated kinase, and significantly reduced pancreatic cancer cell viability. Interestingly, knockdown of GALNT6 caused drastic morphological changes of pancreatic cells, accompanied with the cadherin switching from P-cadherin to E-cadherin. Considering important roles of Mucin 4 in growth and invasion, our findings imply that targeting GALNT6 is a very promising therapeutic strategy for treatment of pancreatic cancer patients who still have very limited treatment modalities.

Purpose: Squamous cell carcinoma of the head and neck (SCCHN) is a lethal cancer with a suboptimal 5-year overall survival of approximately 50% with surgery and/or definitive chemoradiotherapy. Novel treatments are thus urgently awaited. Immunotherapy with checkpoint blockade has emerged as a promising option for patients with recurrent/metastatic SCCHN; however, it has not been investigated in the curative-intent setting yet. The purpose of this study was to investigate the T-cell receptor repertoire and the tumor microenvironment in tumor tissues of SCCHN patients with locoregionally advanced disease. Experimental Design: We performed T-cell receptor sequencing of tumor tissues from 44 patients with locoregionally advanced SCCHN prior to treatment with definitive chemoradiotherapy and correlated the T-cell clonality and the mRNA expression levels of immune-related genes with clinicopathologic parameters. Results: Clonal expansion of T cells was significantly higher in human papilloma virus (HPV)–negative compared with HPV-positive tumors, signifying more robust antigen presentation in HPV-negative tumors. The latter was supported by the higher percentage of HPV-negative tumors expressing HLA-A protein compared with HPV-positive tumors (P = 0.049). Higher GRZB levels correlated significantly with longer recurrence-free survival (log-rank, P = 0.003) independent of tumor size, nodal stage, and HPV status. Conclusions: Our findings support clonal expansion of T cells in SCCHN patients with locoregionally advanced disease and imply differences in the antigen presentation capacity between HPV-negative and HPV-positive tumors. Elevated GRZB mRNA levels may also serve as a favorable and independent predictor of outcome in SCCHN patients treated with chemoradiotherapy. These data provide rationale for the introduction of immunotherapeutic approaches in the curative-intent setting. Clin Cancer Res; 23(16); 4897–907. ©2017 AACR.

Radiotherapy remains a key treatment modality for both primary and metastatic brain tumors. Significant technological advances in precision radiotherapy, such as stereotactic radiosurgery and intensity-modulated radiotherapy, have contributed to improved clinical outcomes. Notably, however, molecular genetics is not yet widely used to inform brain radiotherapy treatment. By comparison, genetic testing now plays a significant role in guiding targeted therapies and immunotherapies, particularly for brain metastases (BM) of lung cancer, breast cancer, and melanoma. Given increasing evidence of the importance of tumor genetics to radiation response, this may represent a currently under-utilized means of enhancing treatment outcomes. In addition, recent studies have shown potentially actionable mutations in BM which are not present in the primary tumor. Overall, this suggests that further investigation into the pathways mediating radiation response variability is warranted. Here, we provide an overview of key mechanisms implicated in BM radiation resistance, including intrinsic and acquired resistance and intratumoral heterogeneity. We then discuss advances in tumor sampling methods, such as a collection of cell-free DNA and RNA, as well as progress in genomic analysis. We further consider how these tools may be applied to provide personalized radiotherapy for BM, including patient stratification, detection of radiotoxicity, and use of radiosensitization agents. In addition, we describe recent developments in preclinical models of BM and consider their relevance to investigating radiation response. Given the increase in clinical trials evaluating the combination of radiotherapy and targeted therapies, as well as the rising incidence of BM, it is essential to develop genomically informed approaches to enhance radiation response.

Brain metastases (BM), which most commonly originate from lung, breast, or skin cancers, remain a major clinical challenge, with standard treatments such as stereotactic radiosurgery (SRS), surgical resection, and whole-brain radiation therapy (WBRT). The prognosis for patients with BM remains poor, with a median overall survival (OS) of just 10–16 months. Although recent advances in systemic therapies, including small molecule inhibitors, monoclonal antibodies, chemotherapeutics, and gene therapies, have demonstrated success in other malignancies, their effectiveness in central nervous system (CNS) cancers is significantly limited by poor blood–brain barrier (BBB) permeability and subtherapeutic drug concentrations in the brain. Nanoparticle-based drug delivery systems have emerged as a promising strategy to overcome these limitations by enhancing CNS drug penetration and selectively targeting metastatic brain tumor cells while minimizing off-target effects. This review summarizes recent preclinical and clinical developments in nanoparticle-based therapies for BM. It is evident from these studies that NPs can carry with them a range of therapeutics, including chemotherapy, immunotherapy, small molecule inhibitors, gene therapies, radiosensitizers, and modulators of tumor microenvironment to the BM. Moreover, preclinical studies have shown encouraging efficacy in murine models, highlighting the potential of these platforms to improve therapeutic outcomes. However, clinical translation remains limited, with few ongoing trials. To close this translational gap, future work must address clinical challenges such as trial design, regulatory hurdles, and variability in BBB permeability while developing personalized nanoparticle-based therapies tailored to individual tumor characteristics.

The diagnosis of brain tumors typically relies on magnetic resonance imaging (MRI), computed tomography (CT), and invasive procedures like biopsies or surgical resection for confirmation and genetic profiling. However, these methods have limitations, especially in distinguishing treatment effects like pseudo-progression from actual tumor progression, and repeated biopsies pose risks. Liquid biopsy (LB) offers a non-invasive alternative, detecting tumor-derived biomarkers in blood and cerebrospinal fluid (CSF). Despite its potential, the low concentration of brain tumor biomarkers in blood due to the blood-brain barrier (BBB), limits the clinical utility of LB. MRI-guided focused ultrasound (MRgFUS) combined with microbubbles provides a novel solution by temporarily disrupting the BBB, facilitating the passage of therapeutic agents, and enabling tumor biomarker detection. This technique, termed “sonobiopsy,” enables non-invasive biomarker collection for liquid biopsy, potentially improving brain tumor diagnosis and monitoring.