Advancing Inclusive Research (AIR) Site Alliance: Facilitating the inclusion of historically underrepresented people in oncology and ophthalmology clinical research.

Background: The Advancing Inclusive Research (AIR) Site Alliance is composed of clinical research centers that partner with Genentech, a biotechnology company, to advance the representation of diverse patient populations in its oncology and ophthalmology clinical trials, test recruitment, and retention approaches and establish best practices to leverage across the industry to achieve health equity.

Methods: Through a data-driven selection process, Genentech identified 6 oncology and 3 ophthalmology partners that focus on reaching historically underrepresented patients in clinical trials and worked collaboratively to share knowledge and explore original ways of increasing clinical study access for every patient, including sites co-creation of a Protocol Entry Criteria Guideline with inclusion principles.

Results: For patients, three publicly available educational videos about clinical trials were created in multiple languages.

Ribosome biosynthesis and Hedgehog activity are cooperative actionable signaling mechanisms in breast cancer following radiotherapy.

Hyperactivated ribosome biosynthesis is attributed to a need for elevated protein synthesis that accommodates cell growth and division, and is characterized by nucleomorphometric alterations and increased nucleolar counts. Ribosome biogenesis is challenged when DNA-damaging treatments such as radiotherapy are utilized. Tumor cells that survive radiotherapy form the basis of recurrence, tumor progression, and metastasis.

The regulation of DNA end resection by chromatin response to DNA double strand breaks.

DNA double-strand breaks (DSBs) constantly arise upon exposure to genotoxic agents and during physiological processes. The timely repair of DSBs is important for not only the completion of the cellular functions involving DSBs as intermediates, but also the maintenance of genome stability. There are two major pathways dedicated to DSB repair: homologous recombination (HR) and non-homologous end joining (NHEJ).

A Flow Cytometry-Based Method for Analyzing DNA End Resection in G- and G-Phase Mammalian Cells.

DNA double strand breaks (DSBs) constantly arise in cells during normal cellular processes or upon exposure to genotoxic agents, and are repaired mostly by homologous recombination (HR) and non-homologous end joining (NHEJ). One key determinant of DNA DSB repair pathway choice is the processing of broken DNA ends to generate single strand DNA (ssDNA) overhangs, a process termed DNA resection. The generation of ssDNA overhangs commits DSB repair through HR and inhibits NHEJ.

DNA-PK promotes DNA end resection at DNA double strand breaks in G cells.

DNA double-strand break (DSB) repair by homologous recombination is confined to the S and G phases of the cell cycle partly due to 53BP1 antagonizing DNA end resection in G phase and non-cycling quiescent (G) cells where DSBs are predominately repaired by non-homologous end joining (NHEJ). Unexpectedly, we uncovered extensive MRE11- and CtIP-dependent DNA end resection at DSBs in G murine and human cells. A whole genome CRISPR/Cas9 screen revealed the DNA-dependent kinase (DNA-PK) complex as a key factor in promoting DNA end resection in G cells.

A Whole Genome CRISPR/Cas9 Screening Approach for Identifying Genes Encoding DNA End-Processing Proteins.

DNA double-strand breaks (DSBs) are mainly repaired by homologous recombination (HR) and non-homologous end joining (NHEJ). The choice of HR or NHEJ is dictated in part by whether the broken DNA ends are resected to generate extended single-stranded DNA (ssDNA) overhangs, which are quickly bound by the trimeric ssDNA binding complex RPA, the first step of HR. Here we describe a series of protocols for generating Abelson murine leukemia virus-transformed pre-B cells (abl pre-B cells) with stably integrated inducible Cas9 that can be used to identify and study novel pathways regulating DNA end processing.

RNF2 ablation reprograms the tumor-immune microenvironment and stimulates durable NK and CD4 T-cell-dependent antitumor immunity.

Expanding the utility of immune-based cancer treatments is a clinical challenge due to tumor-intrinsic factors that suppress the immune response. Here we report the identification of tumoral ring finger protein 2 (RNF2), the core subunit of polycomb repressor complex 1, as a negative regulator of antitumor immunity in various human cancers, including breast cancer. In syngeneic murine models of triple-negative breast cancer, we found that deleting genes encoding the polycomb repressor complex 1 subunits Rnf2, BMI1 proto-oncogene, polycomb ring finger (Bmi1), or the downstream effector of Rnf2, remodeling and spacing factor 1 (Rsf1), was sufficient by itself to induce durable tumor rejection and establish immune memory by enhancing infiltration and activation of natural killer and CD4 T cells, but not CD8 T cells, into the tumor and enabled their cooperativity.

Role of 53BP1 in end protection and DNA synthesis at DNA breaks.

Double-strand break (DSB) repair choice is greatly influenced by the initial processing of DNA ends. 53BP1 limits the formation of recombinogenic single-strand DNA (ssDNA) in BRCA1-deficient cells, leading to defects in homologous recombination (HR). However, the exact mechanisms by which 53BP1 inhibits DSB resection remain unclear.

The RNF8 and RNF168 Ubiquitin Ligases Regulate Pro- and Anti-Resection Activities at Broken DNA Ends During Non-Homologous End Joining.

The RING-type E3 ubiquitin ligases RNF8 and RNF168 recruit DNA damage response (DDR) factors to chromatin flanking DNA double strand breaks (DSBs) including 53BP1, which protects DNA ends from resection during DNA DSB repair by non-homologous end joining (NHEJ). Deficiency of RNF8 or RNF168 does not lead to demonstrable NHEJ defects, but like deficiency of 53BP1, the combined deficiency of XLF and RNF8 or RNF168 leads to diminished NHEJ in lymphocytes arrested in G/G phase. The function of RNF8 in NHEJ depends on its E3 ubiquitin ligase activity.

LIN37-DREAM prevents DNA end resection and homologous recombination at DNA double-strand breaks in quiescent cells.

DNA double-strand break (DSB) repair by homologous recombination (HR) is thought to be restricted to the S- and G- phases of the cell cycle in part due to 53BP1 antagonizing DNA end resection in G-phase and non-cycling quiescent (G) cells. Here, we show that LIN37, a component of the DREAM transcriptional repressor, functions in a 53BP1-independent manner to prevent DNA end resection and HR in G cells. Loss of LIN37 leads to the expression of HR proteins, including BRCA1, BRCA2, PALB2, and RAD51, and promotes DNA end resection in G cells even in the presence of 53BP1.

Does health literacy impact technological comfort in cancer patients?

Introduction: As healthcare systems are adapting due to COVID-19, there has been an increased need for telehealth in the outpatient setting. Not all patients have been comfortable with this transition. We sought to determine the relationship between health literacy and technological comfort in our cancer patients.

Sarco/endoplasmic reticulum Ca2+-ATPase (SERCA) activity is required for V(D)J recombination.

A whole-genome CRISPR/Cas9 screen identified ATP2A2, the gene encoding the Sarco/endoplasmic reticulum Ca2+-ATPase (SERCA) 2 protein, as being important for V(D)J recombination. SERCAs are ER transmembrane proteins that pump Ca2+ from the cytosol into the ER lumen to maintain the ER Ca2+ reservoir and regulate cytosolic Ca2+-dependent processes. In preB cells, loss of SERCA2 leads to reduced V(D)J recombination kinetics due to diminished RAG-mediated DNA cleavage.

DNA double-strand breaks induce H2Ax phosphorylation domains in a contact-dependent manner.

Efficient repair of DNA double-strand breaks (DSBs) requires a coordinated DNA Damage Response (DDR), which includes phosphorylation of histone H2Ax, forming γH2Ax. This histone modification spreads beyond the DSB into neighboring chromatin, generating a DDR platform that protects against end disassociation and degradation, minimizing chromosomal rearrangements. However, mechanisms that determine the breadth and intensity of γH2Ax domains remain unclear.

Loss of H3K36 Methyltransferase SETD2 Impairs V(D)J Recombination during Lymphoid Development.

Repair of DNA double-stranded breaks (DSBs) during lymphocyte development is essential for V(D)J recombination and forms the basis of immunoglobulin variable region diversity. Understanding of this process in lymphogenesis has historically been centered on the study of RAG1/2 recombinases and a set of classical non-homologous end-joining factors. Much less has been reported regarding the role of chromatin modifications on this process.

DNA damage responses in murine Pre-B cells with genetic deficiencies in damage response genes.

DNA damage can be generated in multiple ways from genotoxic and physiologic sources. Genotoxic damage is known to disrupt cellular functions and is lethal if not repaired properly. We compare the transcriptional programs activated in response to genotoxic DNA damage induced by ionizing radiation (IR) in abl pre-B cells from mice deficient in DNA damage response (DDR) genes , and .

Regional Gene Repression by DNA Double-Strand Breaks in G Phase Cells.

DNA damage responses (DDR) to double-strand breaks (DSBs) alter cellular transcription programs at the genome-wide level. Through processes that are less well understood, DSBs also alter transcriptional responses locally, which may be important for efficient DSB repair. Here, we developed an approach to elucidate the -acting responses to DSBs in G phase cells.

XLF and H2AX function in series to promote replication fork stability.

XRCC4-like factor (XLF) is a non-homologous end joining (NHEJ) DNA double strand break repair protein. However, XLF deficiency leads to phenotypes in mice and humans that are not necessarily consistent with an isolated defect in NHEJ. Here we show that XLF functions during DNA replication.

At the intersection of DNA damage and immune responses.

DNA damage occurs on exposure to genotoxic agents and during physiological DNA transactions. DNA double-strand breaks (DSBs) are particularly dangerous lesions that activate DNA damage response (DDR) kinases, leading to initiation of a canonical DDR (cDDR). This response includes activation of cell cycle checkpoints and engagement of pathways that repair the DNA DSBs to maintain genomic integrity.

A Path(way) to Keeping Your Synapses on an Even Keel.

In this issue of Neuron, Harris et al. (2018) show that a signal transduction pathway normally exploited by the innate immune system in recognizing foreign agents plays a critical role in controlling a synapse's ability to maintain stability in the efficacy of synaptic transmission over both rapid and prolonged timescales.

Cell circuits between B cell progenitors and IL-7 mesenchymal progenitor cells control B cell development.

B cell progenitors require paracrine signals such as interleukin-7 (IL-7) provided by bone marrow stromal cells for proliferation and survival. Yet, how B cells regulate access to these signals in vivo remains unclear. Here we show that proB and IL-7 cells form a cell circuit wired by IL-7R signaling, which controls CXCR4 and focal adhesion kinase (FAK) expression and restricts proB cell movement due to increased adhesion to IL-7CXCL12 cells.

MRI Is a DNA Damage Response Adaptor during Classical Non-homologous End Joining.

The modulator of retrovirus infection (MRI or CYREN) is a 30-kDa protein with a conserved N-terminal Ku-binding motif (KBM) and a C-terminal XLF-like motif (XLM). We show that MRI is intrinsically disordered and interacts with many DNA damage response (DDR) proteins, including the kinases ataxia telangiectasia mutated (ATM) and DNA-PKcs and the classical non-homologous end joining (cNHEJ) factors Ku70, Ku80, XRCC4, XLF, PAXX, and XRCC4. MRI forms large multimeric complexes that depend on its N and C termini and localizes to DNA double-strand breaks (DSBs), where it promotes the retention of DDR factors.

The histone chaperone ASF1 regulates the activation of ATM and DNA-PKcs in response to DNA double-strand breaks.

The Ataxia-telangiectasia mutated (ATM) kinase and the DNA-dependent protein kinase catalytic subunit (DNA-PKcs) are activated by DNA double-strand breaks (DSBs). These DSBs occur in the context of chromatin but how chromatin influences the activation of these kinases is not known. Here we show that loss of the replication-dependent chromatin assembly factors ASF1A/B or CAF-1 compromises ATM activation, while augmenting DNA-PKcs activation, in response to DNA DSBs.