Minority of Oncologists and Primary Care Physicians Fully Discuss Survivorship Care Plans With Cancer Survivors

“Of 53 National Cancer Institute cancer centers, only 43% report implementing survivorship care plans for at least some of their cancer survivors. In a study reported in the Journal of Clinical Oncology, Blanch-Hartigan et al found that a minority of a nationally representative sample of oncologists and primary care physicians routinely discuss all aspects of survivorship care or furnish survivorship care plans for cancer survivors.”

Targeting the Tumor Microenvironment with Interferon-β Bridges Innate and Adaptive Immune Responses

“Antibodies (Abs) that preferentially target oncogenic receptors have been increasingly used for cancer therapy, but tumors often acquire intrinsic Ab resistance after prolonged and costly treatment. Herein we armed the Ab with IFNβ and observed that it is more potent than the first generation of Ab for controlling Ab-resistant tumors. This strategy controls Ab resistance by rebridging suppressed innate and adaptive immunity in the tumor microenvironment. Mechanistically, Ab-IFNβ therapy primarily and directly targets intratumoral dendritic cells, which reactivate CTL by increasing antigen cross-presentation within the tumor microenvironment. Additionally, blocking PD-L1, which is induced by Ab-IFNβ treatment, overcomes treatment-acquired resistance and completely eradicates established tumors. This study establishes a next-generation Ab-based immunotherapy that targets and eradicates established Ab-resistant tumors.”

Identification of cancer initiating cells in K-Ras driven lung adenocarcinoma

K-RAS oncogene-driven lung adenocarcinomas is one of the most malignant human tumors for which there are no efficacious therapeutic strategies. Here, we have used a mouse tumor model that closely recapitulates this human disease to illustrate that adult lung cells are uniquely sensitive to transformation by this oncogene. Monitoring lung cells at the single-cell level revealed that they respond differently to K-Ras oncogenic signals. Whereas K-Ras–expressing Clara cells required an inflammatory response to yield hyperplasias and adenomas, alveolar type II cells or their committed precursors led to the generation of malignant adenocarcinoma regardless of their surrounding microenvironment.

Structural, Biochemical, and Clinical Characterization of Epidermal Growth Factor Receptor (EGFR) Exon 20 Insertion Mutations in Lung Cancer

Epidermal growth factor receptor (EGFR) gene mutations (G719X, exon 19 deletions/insertions, L858R, and L861Q) predict favorable responses to EGFR tyrosine kinase inhibitors (TKIs) in advanced non–small cell lung cancer (NSCLC). However, EGFR exon 20 insertion mutations (~10% of all EGFR mutations) are generally associated with insensitivity to available TKIs (gefitinib, erlotinib, and afatinib). The basis of this primary resistance is poorly understood. We studied a broad subset of exon 20 insertion mutations, comparing in vitro TKI sensitivity with responses to gefitinib and erlotinib in NSCLC patients, and found that most are resistant to EGFR TKIs. The crystal structure of a representative TKI-insensitive mutant (D770_N771insNPG) reveals an unaltered adenosine triphosphate–binding pocket, and the inserted residues form a wedge at the end of the C helix that promotes the active kinase conformation. Unlike EGFR-L858R, D770_N771insNPG activates EGFR without increasing its affinity for EGFR TKIs. Unexpectedly, we find that EGFR-A763_Y764insFQEA is highly sensitive to EGFR TKIs in vitro, and patients whose NSCLCs harbor this mutation respond to erlotinib. Analysis of the A763_Y764insFQEA mutant indicates that the inserted residues shift the register of the C helix in the N-terminal direction, altering the structure in the region that is also affected by the TKI-sensitive EGFR-L858R. Our studies reveal intricate differences between EGFR mutations, their biology, and their response to EGFR TKIs.”

Inhibition of Protein Kinase C / Twist1 Signaling Augments Anti-Cancer Effects of Androgen Deprivation and Enzalutamide in Prostate Cancer

“Our findings indicate that PKC/Twist1 signaling contributes to castration resistance as well as enzalutamide resistance in prostate cancer, and suggest that therapeutics targeting PKC/Twist1 signaling, such as PKC inhibitors, represent a promising novel therapeutic strategy for prostate cancer, especially castration-resistant prostate cancer, when combined with enzalutamide.”

Molecular Pathways: Response and resistance to BRAF and MEK inhibitors in BRAFV600E tumors

“The RAS-RAF-MEK-ERK pathway plays a central role in driving proliferation, survival and metastasis signals in tumor cells and the prevalence of oncogenic mutations in RAS and BRAF and upstream nodes makes this pathway the focus of significant oncology drug development efforts. This focus has been justified by the recent success of BRAF and MEK inhibitors in prolonging the lives of patients with BRAFV600E/K mutant melanoma. While it is disappointing that cures are relatively rare, this should not detract from the value of these agents to cancer patients and the opportunity they provide in allowing us to gain a deeper understanding of drug response and resistance. These insights have already provided the basis for the evaluation of alternative dosing regimens and combination therapies in melanoma patients.”

Reproducible copy number variation patterns among single circulating tumor cells of lung cancer patients

In a few milliliters of blood from a cancer patient, one can isolate a few circulating tumor cells (CTCs). Originating from the primary tumor, CTCs seed metastases, which account for the majority of cancer-related deaths. We demonstrate the analyses of the whole genome of single CTCs, which are highly needed for personalized treatment. We discovered that copy number variations (CNVs), one of the major genomic variations, are specific to cancer types, reproducible from cell to cell, and even from patient to patient. We hypothesize that CNVs at certain genomic loci are selected for and lead to metastasis. Our work shows the prospect of noninvasive CTC-based cancer diagnostics.

BRAF Fusions Define a Distinct Molecular Subset of Melanomas with Potential Sensitivity to MEK Inhibition

Recurrent “driver” mutations at specific loci inBRAFNRASKITGNAQ, and GNA11 define clinically relevant molecular subsets of melanoma, but more than 30% are “pan-negative” for these recurrent mutations. We sought to identify additional potential drivers in “pan-negative” melanoma. We identified a novel PAPSS1-BRAF fusion in a “pan-negative” melanoma.  Activation of the mitogen-activated protein kinase (MAPK) pathway in cells by ectopic expression of PAPSS1-BRAF was abrogated by mitogen-activated protein kinase kinase (MEK) inhibition but not by BRAF inhibition. NGS data analysis of 51 additional melanomas revealed a second BRAF fusion (TRIM24-BRAF) in a “pan-negative” sample; MAPK signaling induced by TRIM24-BRAF was also MEK inhibitor sensitive. Through mining TCGA skin cutaneous melanoma dataset, we further identified two potential BRAF fusions in another 49 “pan-negative” cases.

Conclusions: BRAF fusions define a new molecular subset of melanoma, potentially comprising 4% to 8% of “pan-negative” cases. Their presence may explain an unexpected clinical response to MEK inhibitor therapy or assist in selecting patients for MEK-directed therapy.”

Impeding Macrophage Entry into Hypoxic Tumor Areas by Sema3A/Nrp1 Signaling Blockade Inhibits Angiogenesis and Restores Antitumor Immunity

“We report that hypoxia-induced Semaphorin 3A (Sema3A) acts as an attractant for TAMs by triggering vascular endothelial growth factor receptor 1 phosphorylation through the associated holoreceptor, composed of Neuropilin-1 (Nrp1) and PlexinA1/PlexinA4. Importantly, whereas Nrp1 levels are downregulated in the hypoxic environment, Sema3A continues to regulate TAMs in an Nrp1-independent manner by eliciting PlexinA1/PlexinA4-mediated stop signals, which retain them inside the hypoxic niche. Consistently, gene deletion of Nrp1 in macrophages favors TAMs’ entrapment in normoxic tumor regions, which abates their pro-angiogenic and immunosuppressive functions, hence inhibiting tumor growth and metastasis. This study shows that TAMs’ heterogeneity depends on their localization, which is tightly controlled by Sema3A/Nrp1 signaling. “