Not the End of the Odyssey: Parental Perceptions of Whole Exome Sequencing (WES) in Pediatric Undiagnosed Disorders.

Due to the lack of empirical information on parental perceptions of primary results of whole exome sequencing (WES), we conducted a retrospective semi-structured interview with 19 parents of children who had undergone WES. Perceptions explored during the interview included factors that would contribute to parental empowerment such as: parental expectations, understanding of the WES and results, utilization of the WES information, and communication of findings to health/educational professionals and family members. Results of the WES had previously been communicated to families within a novel framework of clinical diagnostic categories: 5/19 had Definite diagnoses, 6/19 had Likely diagnoses, 3/19 had Possible diagnosis and 5/19 had No diagnosis. All parents interviewed expressed a sense of duty to pursue the WES in search of a diagnosis; however, their expectations were tempered by previous experiences with negative genetic testing results. Approximately half the parents worried that a primary diagnosis that would be lethal might be identified; however, the hope of a diagnosis outweighed this concern. Parents were accurately able to summarize their child's WES findings, understood the implications for recurrence risks, and were able to communicate these findings to family and medical/educational providers. The majority of those with a Definite/Likely diagnosis felt that their child's medical care was more focused, or there was a reduction in worry, despite the lack of a specific treatment. Irrespective of diagnostic outcome, parents recommended that follow-up visits be built into the process. Several parents expressed a desire to have all variants of unknown significance (VUS) reported to them so that they could investigate these themselves. Finally, for some families whose children had a Definite/Likely diagnosis, there was remaining frustration and a sense of isolation, due to the limited information that was available about the diagnosed rare disorders and the inability to connect to other families, suggesting that for families with rare genetic disorders, the diagnostic odyssey does not necessarily end with a diagnosis. Qualitative interviewing served a meaningful role in eliciting new information about parental motivations, expectations, and knowledge of WES. Our findings highlight a need for continued communication with families as we navigate the new landscape of genomic sequencing.

The CLCF1-CNTFR axis drives an immunosuppressive tumor microenvironment and blockade enhances the effects of established cancer therapies.

Tumors comprise a complex ecosystem consisting of many cell types that communicate through secreted factors. Targeting these intercellular signaling networks remains an important challenge in cancer research. Cardiotrophin-like cytokine factor 1 (CLCF1) is an interleukin-6 (IL-6) family member secreted by cancer-associated fibroblasts (CAFs) that binds to ciliary neurotrophic factor receptor (CNTFR), promoting tumor growth in lung and liver cancer1,2. A high-affinity soluble receptor (eCNTFR-Fc) that sequesters CLCF1 has anti-oncogenic effects3. However, the role of CLCF1 in mediating cell-cell interactions in cancer has remained unclear. We demonstrate that eCNTFR-Fc has widespread effects on both tumor cells and the tumor microenvironment and can sensitize cancer cells to KRAS inhibitors or immune checkpoint blockade. After three weeks of treatment with eCNTFR-Fc, there is a shift from an immunosuppressive to an immunostimulatory macrophage phenotype as well as an increase in activated T, NKT, and NK cells. Combination of eCNTFR-Fc and αPD1 was significantly more effective than single-agent therapy in a syngeneic allograft model, and eCNTFR-Fc sensitizes tumor cells to αPD1 in a non-responsive GEM model of lung adenocarcinoma. These data suggest that combining eCNTFR-Fc with KRAS inhibition or with αPD1 is a novel therapeutic strategy for lung cancer and potentially other cancers in which these therapies have been used but to date with only modest effect. Overall, we demonstrate the potential of cancer therapies that target cytokines to alter the immune microenvironment.

A prime editor mouse to model a broad spectrum of somatic mutations in vivo.

Genetically engineered mouse models only capture a small fraction of the genetic lesions that drive human cancer. Current CRISPR-Cas9 models can expand this fraction but are limited by their reliance on error-prone DNA repair. Here we develop a system for in vivo prime editing by encoding a Cre-inducible prime editor in the mouse germline. This model allows rapid, precise engineering of a wide range of mutations in cell lines and organoids derived from primary tissues, including a clinically relevant Kras mutation associated with drug resistance and Trp53 hotspot mutations commonly observed in pancreatic cancer. With this system, we demonstrate somatic prime editing in vivo using lipid nanoparticles, and we model lung and pancreatic cancer through viral delivery of prime editing guide RNAs or orthotopic transplantation of prime-edited organoids. We believe that this approach will accelerate functional studies of cancer-associated mutations and complex genetic combinations that are challenging to construct with traditional models.