Atad3a suppresses Pink1-dependent mitophagy to maintain homeostasis of hematopoietic progenitor cells.

Although deletion of certain autophagy-related genes has been associated with defects in hematopoiesis, it remains unclear whether hyperactivated mitophagy affects the maintenance and differentiation of hematopoietic stem cells (HSCs) and committed progenitor cells. Here we report that targeted deletion of the gene encoding the AAA+-ATPase Atad3a hyperactivated mitophagy in mouse hematopoietic cells. Affected mice showed reduced survival, severely decreased bone-marrow cellularity, erythroid anemia and B cell lymphopenia. Those phenotypes were associated with skewed differentiation of stem and progenitor cells and an enlarged HSC pool. Mechanistically, Atad3a interacted with the mitochondrial channel components Tom40 and Tim23 and served as a bridging factor to facilitate appropriate transportation and processing of the mitophagy protein Pink1. Loss of Atad3a caused accumulation of Pink1 and activated mitophagy. Notably, deletion of Pink1 in Atad3a-deficient mice significantly 'rescued' the mitophagy defect, which resulted in restoration of the progenitor and HSC pools. Our data indicate that Atad3a suppresses Pink1-dependent mitophagy and thereby serves a key role in hematopoietic homeostasis.

Phosphorylation of PDHA by AMPK Drives TCA Cycle to Promote Cancer Metastasis.

Cancer metastasis accounts for the major cause of cancer-related deaths. How disseminated cancer cells cope with hostile microenvironments in secondary site for full-blown metastasis is largely unknown. Here, we show that AMPK (AMP-activated protein kinase), activated in mouse metastasis models, drives pyruvate dehydrogenase complex (PDHc) activation to maintain TCA cycle (tricarboxylic acid cycle) and promotes cancer metastasis by adapting cancer cells to metabolic and oxidative stresses. This AMPK-PDHc axis is activated in advanced breast cancer and predicts poor metastasis-free survival. Mechanistically, AMPK localizes in the mitochondrial matrix and phosphorylates the catalytic alpha subunit of PDHc (PDHA) on two residues S295 and S314, which activates the enzymatic activity of PDHc and alleviates an inhibitory phosphorylation by PDHKs, respectively. Importantly, these phosphorylation events mediate PDHc function in cancer metastasis. Our study reveals that AMPK-mediated PDHA phosphorylation drives PDHc activation and TCA cycle to empower cancer cells adaptation to metastatic microenvironments for metastasis.

hDirect-MAP: projection-free single-cell modeling of response to checkpoint immunotherapy.

There is a lack of robust generalizable predictive biomarkers of response to immune checkpoint blockade in multiple types of cancer. We develop hDirect-MAP, an algorithm that maps T cells into a shared high-dimensional (HD) expression space of diverse T cell functional signatures in which cells group by the common T cell phenotypes rather than dimensional reduced features or a distorted view of these features. Using projection-free single-cell modeling, hDirect-MAP first removed a large group of cells that did not contribute to response and then clearly distinguished T cells into response-specific subpopulations that were defined by critical T cell functional markers of strong differential expression patterns. We found that these grouped cells cannot be distinguished by dimensional-reduction algorithms but are blended by diluted expression patterns. Moreover, these identified response-specific T cell subpopulations enabled a generalizable prediction by their HD metrics. Tested using five single-cell RNA-seq or mass cytometry datasets from basal cell carcinoma, squamous cell carcinoma and melanoma, hDirect-MAP demonstrated common response-specific T cell phenotypes that defined a generalizable and accurate predictive biomarker.

Preemptive Versus Reactive Topical Clobetasol for Regorafenib-Induced Hand-Foot Reactions: A Preplanned Analysis of the ReDOS Trial.

BACKGROUND: Hand-foot skin reaction (HFSR) is the most common regorafenib-induced adverse event and is in need of effective prevention and palliation. MATERIALS AND METHODS: The Regorafenib Dose Optimization Study (ReDOS), a four-arm, previously published trial with a 1:1:1:1 randomization scheme, was analyzed in a manner in keeping with the original protocol to assess whether clobetasol 0.05% cream (a corticosteroid) applied to the palms and soles twice per day for 8 weeks was more effective when prescribed preemptively (before the development of HFSR) versus reactively (after the development of HFSR). Patients were assessed during the first two cycles of regorafenib. RESULTS: Sixty-one patients received preemptive clobetasol, and 55 received reactive clobetasol. Groups were balanced on demographics. Over the first two cycles, no evidence of HFSR occurred in 30% with preemptive clobetasol versus 13% with reactive clobetasol (p = .03). During the first cycle, 54% and 45% of patients had no HFSR with preemptive and reactive clobetasol, respectively (p = .35). During the second cycle, 33% and 15% had no HFSR with preemptive and reactive clobetasol, respectively (p = .02). During the second cycle, rates of grade 1, 2, and 3 HFSR were 30%, 8%, and 3%, respectively, with preemptive clobetasol and 43%, 18%, and 7%, respectively, with reactive clobetasol (p = .12). Patient-reported outcomes showed HFSR compromised nearly all activities of daily living with worse quality of life in patients who received reactive versus preemptive clobetasol. No clobetasol-induced adverse events were reported. CONCLUSION: Preemptive clobetasol might lessen regorafenib-induced hand-foot reactions compared with reactive therapy. Further confirmatory studies are needed in a larger patient cohort. IMPLICATIONS FOR PRACTICE: Regorafenib causes hand-foot skin reactions. Preemptive clobetasol, a high-potency topical corticosteroid, appears to lessen the severity of this adverse event. Although further study is needed, the favorable adverse event profile of this intervention might prompt clinicians to discuss this option with their patients.

Diagnosis of thyroid cancer using deep convolutional neural network models applied to sonographic images: a retrospective, multicohort, diagnostic study.

BACKGROUND: The incidence of thyroid cancer is rising steadily because of overdiagnosis and overtreatment conferred by widespread use of sensitive imaging techniques for screening. This overall incidence growth is especially driven by increased diagnosis of indolent and well-differentiated papillary subtype and early-stage thyroid cancer, whereas the incidence of advanced-stage thyroid cancer has increased marginally. Thyroid ultrasound is frequently used to diagnose thyroid cancer. The aim of this study was to use deep convolutional neural network (DCNN) models to improve the diagnostic accuracy of thyroid cancer by analysing sonographic imaging data from clinical ultrasounds. METHODS: We did a retrospective, multicohort, diagnostic study using ultrasound images sets from three hospitals in China. We developed and trained the DCNN model on the training set, 131 731 ultrasound images from 17 627 patients with thyroid cancer and 180 668 images from 25 325 controls from the thyroid imaging database at Tianjin Cancer Hospital. Clinical diagnosis of the training set was made by 16 radiologists from Tianjin Cancer Hospital. Images from anatomical sites that were judged as not having cancer were excluded from the training set and only individuals with suspected thyroid cancer underwent pathological examination to confirm diagnosis. The model's diagnostic performance was validated in an internal validation set from Tianjin Cancer Hospital (8606 images from 1118 patients) and two external datasets in China (the Integrated Traditional Chinese and Western Medicine Hospital, Jilin, 741 images from 154 patients; and the Weihai Municipal Hospital, Shandong, 11 039 images from 1420 patients). All individuals with suspected thyroid cancer after clinical examination in the validation sets had pathological examination. We also compared the specificity and sensitivity of the DCNN model with the performance of six skilled thyroid ultrasound radiologists on the three validation sets. FINDINGS: Between Jan 1, 2012, and March 28, 2018, ultrasound images for the four study cohorts were obtained. The model achieved high performance in identifying thyroid cancer patients in the validation sets tested, with area under the curve values of 0·947 (95% CI 0·935-0·959) for the Tianjin internal validation set, 0·912 (95% CI 0·865-0·958) for the Jilin external validation set, and 0·908 (95% CI 0·891-0·925) for the Weihai external validation set. The DCNN model also showed improved performance in identifying thyroid cancer patients versus skilled radiologists. For the Tianjin internal validation set, sensitivity was 93·4% (95% CI 89·6-96·1) versus 96·9% (93·9-98·6; p=0·003) and specificity was 86·1% (81·1-90·2) versus 59·4% (53·0-65·6; p<0·0001). For the Jilin external validation set, sensitivity was 84·3% (95% CI 73·6-91·9) versus 92·9% (84·1-97·6; p=0·048) and specificity was 86·9% (95% CI 77·8-93·3) versus 57·1% (45·9-67·9; p<0·0001). For the Weihai external validation set, sensitivity was 84·7% (95% CI 77·0-90·7) versus 89·0% (81·9-94·0; p=0·25) and specificity was 87·8% (95% CI 81·6-92·5) versus 68·6% (60·7-75·8; p<0·0001). INTERPRETATION: The DCNN model showed similar sensitivity and improved specificity in identifying patients with thyroid cancer compared with a group of skilled radiologists. The improved technical performance of the DCNN model warrants further investigation as part of randomised clinical trials. FUNDING: The Program for Changjiang Scholars and Innovative Research Team in University in China, and National Natural Science Foundation of China.

Regorafenib dose-optimisation in patients with refractory metastatic colorectal cancer (ReDOS): a randomised, multicentre, open-label, phase 2 study.

BACKGROUND: Regorafenib confers an overall survival benefit in patients with refractory metastatic colorectal cancer; however, the adverse event profile of regorafenib has limited its use. Despite no supportive evidence, various dosing schedules are used clinically to alleviate toxicities. This study evaluated the safety and activity of two regorafenib dosing schedules. METHODS: In this randomised, multicentre, open-label, phase 2 study done in 39 outpatient cancer centres in the USA, adults aged 18 years or older with histologically or cytologically confirmed advanced or metastatic adenocarcinoma of the colon or rectum that was refractory to previous standard therapy, including EGFR inhibitors if KRAS wild-type, were enrolled. Eligible patients had an Eastern Cooperative Oncology Group performance status of 0-1 and had no previous treatment with regorafenib. Patients were randomly assigned (1:1:1:1) into four groups with two distinct regorafenib dosing strategies and two clobetasol usage plans, stratified by hospital. Regorafenib dosing strategies were a dose-escalation strategy (starting dose 80 mg/day orally with weekly escalation, per 40 mg increment, to 160 mg/day regorafenib) if no significant drug-related adverse events occurred and a standard-dose strategy (160 mg/day orally) for 21 days of a 28-day cycle. Clobetasol usage plans (0·05% clobetasol cream twice daily applied to palms and soles) were either pre-emptive or reactive. After randomisation to the four preplanned groups, using the Pocock and Simon dynamic allocation procedures stratified by the treating hospitals, we formally tested the interaction between the two interventions, dosing strategy and clobetasol usage. Given the absence of a significant interaction (p=0·74), we decided to pool the data for the pre-emptive and reactive treatment with clobetasol and compared the two dosing strategies (dose escalation vs standard dose). The primary endpoint was the proportion of evaluable patients (defined as those who were eligible, consented, and received any protocol treatment) initiating cycle 3 and was analysed per protocol. Superiority for dose escalation was declared if the one-sided p value with Fisher's exact test was less than 0·2. This trial is registered with ClinicalTrials.gov, number NCT02368886. This study is fully accrued but remains active. FINDINGS: Between June 2, 2015, and June 22, 2017, 123 patients were randomly assigned to treatment, of whom 116 (94%) were evaluable. The per-protocol population consisted of 54 patients in the dose-escalation group and 62 in the standard-dose group. At data cutoff on July 24, 2018, median follow-up was 1·18 years (IQR 0·98-1·57). The primary endpoint was met: 23 (43%, 95% CI 29-56) of 54 patients in the dose-escalation group initiated cycle 3 versus 16 (26%, 15-37) of 62 patients in the standard-dose group (one-sided p=0·043). The most common grade 3-4 adverse events were fatigue (seven [13%] patients in the dose-escalation group vs 11 [18%] in the standard-dose group), hand-foot skin reaction (eight [15%] patients vs ten [16%] patients), abdominal pain (nine [17%] patients vs four [6%] patients), and hypertension (four [7%] patients vs nine [15%] patients). 14 patients had at least one drug-related serious adverse event: six patients in the dose-escalation group and eight patients in the standard-dose group. There was one probable treatment-related death in the standard-dose group (myocardial infarction). INTERPRETATION: The dose-escalation dosing strategy represents an alternative approach for optimising regorafenib dosing with comparable activity and lower incidence of adverse events and could be implemented in clinical practice on the basis of these data. FUNDING: Bayer HealthCare Pharmaceuticals.

Oncology Navigation Decreases Time to Treatment in Patients with Pancreatic Malignancy.

BACKGROUND: Care of pancreatic cancer patients has become increasingly complex, which has led to delays in the initiation of therapy. Nurse navigators have been added to care teams, in part, to ameliorate this delay. This study investigated the difference in time from first oncology visit to first treatment date in patients with any pancreatic malignancy before and after the addition of an Oncology Navigator. METHODS: A single-institution database of patients with any pancreatic neoplasm evaluated by a provider in radiation, medical, or surgical oncology between 1 October 2015 and 30 September 2017 was analyzed. After 1 October 2016, an Oncology Navigator met patients at their initial visit and coordinated care throughout treatment. The cohort was divided into two groups: patients evaluated prior to the implementation of an Oncology Navigator and patients evaluated after implementation. Patient demographics and time from first visit to first intervention were compared. RESULTS: Overall, 147 patients with a new diagnosis of pancreatic neoplasm were evaluated; 57 patients were seen prior to the start of the Oncology Navigator program and 79 were evaluated after the navigation program was implemented. On univariate analysis, time from first contact by any provider to intervention was 46 days prior to oncology navigation and 26 days after implementation of oncology navigation (p = 0.005). While controlling for other covariates, employment of the Oncology Navigator decreased the time from first contact by any provider to intervention by almost 16 days (p = 0.009). CONCLUSIONS: Implementing an oncology navigation program significantly decreased time to treatment in patients with pancreatic malignancy.

Favorable outcome of patients with lung adenocarcinoma harboring POLE mutations and expressing high PD-L1.

Mutations in polymerase ε (POLE) confer favorable prognosis and outcomes in various cancer types, but their role in non-small cell lung cancer (NSCLC) is unknown. Utilizing the data of 513 patients with adenocarcinoma (LUAD) and 497 patients with squamous cell carcinoma (LUSC) from The Cancer Genome Atlas (TCGA) cohort, we tested the prognostic value of POLE mutations and programmed cell death ligand 1 (PD-L1) expression in the two main subtypes of NSCLC. POLE mutation is a favorable biomarker for the improved overall survival (OS) of the LUSC patients (P = 0.033, 28 mutant vs. 469 wildtype patients), but not that of the LUAD patients (P = 0.12, 31 mutant vs. 482 wildtype patients). POLE-mutant LUAD patients with high expression of PD-L1 (Mut-High, n = 6) exhibited improved OS (P = 0.024) when compared to POLE-mutant patients with low PD-L1 expression (Mut-Low, n = 24) and other patients without POLE mutation (n = 476). This benefit was not due to the high content of the tumor infiltrating lymphocytes. Instead, the antitumor immune response was activated in Mut-High patients so that these patients were likely responding more effectively to immuno-oncology (IO) treatments; whereas genes involved with metabolic pathways were enriched in Mut-Low group, which may cause the decreased OS of these patients. Our study sheds light on the molecular basis of NSCLC and adds to our understanding of responses to chemotherapy and IO therapy.

Safety and tolerability of the first-in-class agent CPI-613 in combination with modified FOLFIRINOX in patients with metastatic pancreatic cancer: a single-centre, open-label, dose-escalation, phase 1 trial.

BACKGROUND: Pancreatic cancer statistics are dismal, with a 5-year survival of less than 10%, and more than 50% of patients presenting with metastatic disease. Metabolic reprogramming is an emerging hallmark of pancreatic adenocarcinoma. CPI-613 is a novel anticancer agent that selectively targets the altered form of mitochondrial energy metabolism in tumour cells, causing changes in mitochondrial enzyme activities and redox status that lead to apoptosis, necrosis, and autophagy of tumour cells. We aimed to establish the maximum tolerated dose of CPI-613 when used in combination with modified FOLFIRINOX chemotherapy (comprising oxaliplatin, leucovorin, irinotecan, and fluorouracil) in patients with metastatic pancreatic cancer. METHODS: In this single-centre, open-label, dose-escalation phase 1 trial, we recruited adult patients (aged ≥18 years) with newly diagnosed metastatic pancreatic adenocarcinoma from the Comprehensive Cancer Center of Wake Forest Baptist Medical Center (Winston-Salem, NC, USA). Patients had good bone marrow, liver and kidney function, and good performance status (Eastern Cooperative Oncology Group [ECOG] performance status 0-1). We studied CPI-613 in combination with modified FOLFIRINOX (oxaliplatin at 65 mg/m2, leucovorin at 400 mg/m2, irinotecan at 140 mg/m2, and fluorouracil 400 mg/m2 bolus followed by 2400 mg/m2 over 46 h). We applied a two-stage dose-escalation scheme (single patient and traditional 3+3 design). In the single-patient stage, one patient was accrued per dose level. The starting dose of CPI-613 was 500 mg/m2 per day; the dose level was then escalated by doubling the previous dose if there were no adverse events worse than grade 2 within 4 weeks attributed as probably or definitely related to CPI-613. The traditional 3+3 dose-escalation stage was triggered if toxic effects attributed as probably or definitely related to CPI-613 were grade 2 or worse. The dose level for CPI-613 for the first cohort in the traditional dose-escalation stage was the same as that used in the last cohort of the single-patient dose-escalation stage. The primary objective was to establish the maximum tolerated dose of CPI-613 (as assessed by dose-limiting toxicities). This trial is registered with ClinicalTrials.gov, number NCT01835041, and is closed to recruitment. FINDINGS: Between April 22, 2013, and Jan 8, 2016, we enrolled 20 patients. The maximum tolerated dose of CPI-613 was 500 mg/m2. The median number of treatment cycles given at the maximum tolerated dose was 11 (IQR 4-19). Median follow-up of the 18 patients treated at the maximum tolerated dose was 378 days (IQR 250-602). Two patients enrolled at a higher dose of 1000 mg/m2, and both had a dose-limiting toxicity. Two unexpected serious adverse events occurred, both for the first patient enrolled. Expected serious adverse events were: thrombocytopenia, anaemia, and lymphopenia (all for patient number 2; anaemia and lymphopenia were dose-limiting toxicities); hyperglycaemia (in patient number 7); hypokalaemia, hypoalbuminaemia, and sepsis (patient number 11); and neutropenia (patient number 20). No deaths due to adverse events were reported. For the 18 patients given the maximum tolerated dose, the most common grade 3-4 non-haematological adverse events were hyperglycaemia (ten [55%] patients), hypokalaemia (six [33%]), peripheral sensory neuropathy (five [28%]), diarrhoea (five [28%]), and abdominal pain (four [22%]). The most common grade 3-4 haematological adverse events were neutropenia (five [28%] of 18 patients), lymphopenia (five [28%]), anaemia (four [22%], and thrombocytopenia in three [17%]). Sensory neuropathy (all grade 1-3) was recorded in 17 (94%) of the 18 patients and was managed with dose de-escalation or discontinuation per standard of care. No patients died while on active treatment; 11 study participants died, with cause of death as terminal pancreatic cancer. Of the 18 patients given the maximum tolerated dose, 11 (61%) achieved an objective (complete or partial) response. INTERPRETATION: A maximum tolerated dose of CPI-613 was established at 500 mg/m2 when used in combination with modified FOLFIRINOX in patients with metastatic pancreatic cancer. The findings of clinical activity will require validation in a phase 2 trial. FUNDING: Comprehensive Cancer Center of Wake Forest Baptist Medical Center.

An HF exposure system for mice with improved efficiency.

An exposure system that addresses difficulties that arise for exposure of small animals at low frequencies with a high exposure level is presented. The system, intended to operate at 27 MHz, consists of two identical transverse electro-magnetic (TEM) cells for exposure and sham exposure of groups of 16 free-running mice housed in pairs within standard cages, capable of exposure over extended daily periods while being provided food and water. Inclusion of the exposure cell in a half-wavelength resonator has been developed as a new paradigm to enhance field strength for an increase of >50-fold in available specific absorption rate (SAR) levels compared to traditional TEM cell configurations. The system described allows both daily and weekly exposure schedules and supports blinded protocols with continuous wave (CW) and amplitude modulation (AM) signals with programmable modulation depths and frequencies. Electric field (E-field) homogeneity across the TEM cell along a vertical plane (orthogonal to the axis of the TEM line) was within 3.3%, and 3.1% along the horizontal plane. Accurate and comprehensive dosimetric assessments based on whole-body and organ-specific SAR essential for in vivo bioelectromagnetic experiments are presented, which takes into account various factors (e.g., mouse activities, close proximity, and field homogeneity). Average SAR levels are controllable in the range of 1 mW/kg to 2 W/kg, with expanded uncertainty (k = 2) of 1 dB and instantaneous variation (k = 1) of 4 dB.

SMAD4 is a potential prognostic marker in human breast carcinomas.

SMAD4 is a downstream mediator of transforming growth factor beta. While its tumor suppressor function has been investigated as a prognostic biomarker in several human malignancies, its role as a prognostic marker in breast carcinoma is still undefined. We investigated SMAD4 expression in breast carcinoma samples of different histologic grades to evaluate the association between SMAD4 and outcome in breast cancer. We also investigated the role of SMAD4 expression status in MDA-MB-468 breast cancer cells in responding to TGF-ß stimulation. SMAD4 expression was assessed in 53 breast ductal carcinoma samples and in the surrounding normal tissue from 50 of the samples using immunohistochemistry, Western blot, and real-time PCR. TGF-ß-SMAD and non-SMAD signaling was assessed by Western blot in MDA-MB-468 cells with and without SMAD4 restoration. SMAD4 expression was reduced in ductal breast carcinoma as compared to surrounding uninvolved ductal breast epithelia (p < 0.05). SMAD4 expression levels decreased from Grade 1 to Grade 3 ductal breast carcinoma as assessed by immunohistochemistry (p < 0.05). Results were recapitulated by tissue array. In addition, immunohistochemistry results were further confirmed at the protein and mRNA level. We then found that non-SMAD MEK/MAPK signaling was significantly different between SMAD4 expressing MDA-MB-468 cells and SMAD4-null MDA-MB-468 cells. This is the first study indicating that SMAD4 plays a key role in shifting MAPK signaling. Further, we have demonstrated that SMAD4 has a potential role in the development of breast carcinoma and SMAD4 was a potential prognostic marker of breast carcinoma. Our findings further support the role of SMAD4 in breast carcinoma development. In addition, we observed an inverse relationship between SMAD4 levels and breast carcinoma histological grade. Our finding indicated that SMAD4 expression level in breast cancer cells played a role in responding non-SMAD signaling but not the canonic SMAD signaling. Further mechanistic studies are necessary to establish the role of SMAD4 in breast carcinoma prognosis and potential specific targeting.

Genetic/familial high-risk assessment: breast and ovarian, version 1.2014.

During the past few years, several genetic aberrations that may contribute to increased risks for development of breast and/or ovarian cancers have been identified. The NCCN Guidelines for Genetic/Familial High-Risk Assessment: Breast and Ovarian focus specifically on the assessment of genetic mutations in BRCA1/BRCA2, TP53, and PTEN, and recommend approaches to genetic testing/counseling and management strategies in individuals with these mutations. This portion of the NCCN Guidelines includes recommendations regarding diagnostic criteria and management of patients with Cowden Syndrome/PTEN hamartoma tumor syndrome.

TGFBR1 and cancer susceptibility.

Transforming growth factor beta (TGF-ß) is a potent inhibitor of cell growth. TGFBR1 6A is a polymorphism consisting of a 9-base pair in-frame deletion within exon 1 of the type I TGF-ß receptor (TGFBR1), which results in a receptor with decreased TGF-ß signaling capability. The discovery of an association between TGFBR1*6A and cancer susceptibility led to the hypothesis that hypomorphic variants of the TGF-ß signaling pathway may predispose to the development of cancer. This hypothesis was tested in vivo with the development of a mouse model of Tgfbr1 haploinsufficiency. Tgfbr1 (+/-) mice developed twice as many intestinal tumors as Tgfbr1 (+/+). Tgfbr1 haploinsufficiency was also associated with early onset adenocarcinoma and increased tumor cell proliferation. A case control study identified two haplotypes associated with constitutively decreased TGFBR1 and substantially increased colorectal cancer risk indicating that TGFBR1 may act as a potent modifier of cancer risk.

Targeting guanine nucleotide exchange factors for novel cancer drug discovery.

INTRODUCTION: Guanine nucleotide exchange factors (GEFs) regulate the activation of small GTPases (G proteins) of the Ras superfamily proteins controlling cellular functions. Ras superfamily proteins act as 'molecular switches' that are turned 'ON' by guanine exchange. There are five major groups of Ras family GTPases: Ras, Ran, Rho, Rab and Arf, with a variety of different GEFs regulating their GTP loading. GEFs have been implicated in various diseases including cancer. This makes GEFs attractive targets to modulate signaling networks controlled by small GTPases. AREAS COVERED: In this review, the roles and mechanisms of GEFs in malignancy are outlined. The mechanism of guanine exchange activity by GEFs on a small GTPase is illustrated. Then, some examples of GEFs that are significant in cancer are presented with a discussion on recent progress in therapeutic targeting efforts using a variety of approaches. EXPERT OPINION: Recently, GEFs have emerged as potential therapeutic targets for novel cancer drug development. Targeting small GTPases is challenging; thus, targeting their activation by GEFs is a promising strategy. Most GEF-targeted drugs are still in preclinical development. A deeper biological understanding of the underlying mechanisms of GEF activity and utilizing advanced technology are necessary to enhance drug discovery for GEFs in cancer.

TGFß in pancreas and colorectal cancer: opportunities to overcome therapeutic resistance.

TGFß is a pleiotropic signaling pathway, which plays a pivotal role in regulating a multitude of cellular functions. TGFß has a dual role in cell regulation where it induces growth inhibition and cell death; however, it can switch to a growth-promoting state under cancerous conditions. TGFß is upregulated in CRC and pancreatic cancer, altering the tumor microenvironment, immune system, and promoting a mesenchymal state. The upregulation of TGFß in certain cancers leads to resistance to immunotherapy, and attempts to inhibit TGFß expression have led to reduced therapeutic resistance when combined with chemo- and immunotherapy. Here, we review the current TGFß inhibitor drugs in clinical trials for pancreatic and colorectal cancer, with the goal of uncovering advances in improving clinical efficacy for TGFß combinational treatments in patients. Furthermore, we discuss the relevance of alterations in TGFß signaling and germline variants in the context of personalizing treatment for patients who show lack of response to current therapeutics.

Targeted treatment of cancer with radiofrequency electromagnetic fields amplitude-modulated at tumor-specific frequencies.

In the past century, there have been many attempts to treat cancer with low levels of electric and magnetic fields. We have developed noninvasive biofeedback examination devices and techniques and discovered that patients with the same tumor type exhibit biofeedback responses to the same, precise frequencies. Intrabuccal administration of 27.12 MHz radiofrequency (RF) electromagnetic fields (EMF), which are amplitude-modulated at tumor-specific frequencies, results in long-term objective responses in patients with cancer and is not associated with any significant adverse effects. Intrabuccal administration allows for therapeutic delivery of very low and safe levels of EMF throughout the body as exemplified by responses observed in the femur, liver, adrenal glands, and lungs. In vitro studies have demonstrated that tumor-specific frequencies identified in patients with various forms of cancer are capable of blocking the growth of tumor cells in a tissue- and tumor-specific fashion. Current experimental evidence suggests that tumor-specific modulation frequencies regulate the expression of genes involved in migration and invasion and disrupt the mitotic spindle. This novel targeted treatment approach is emerging as an appealing therapeutic option for patients with advanced cancer given its excellent tolerability. Dissection of the molecular mechanisms accounting for the anti-cancer effects of tumor-specific modulation frequencies is likely to lead to the discovery of novel pathways in cancer.

Feasibility of Systems Support Mapping to guide patient-driven health self-management in colorectal cancer survivors.

OBJECTIVE: To evaluate feasibility of System Support Mapping (MAP), a systems thinking activity that involves creating a diagram of existing self-management activities (e.g. symptom management, health behaviors) to facilitate autonomous engagement in optimal self-management. DESIGN: One-arm pilot study of MAP in colorectal cancer survivors (NCT03520283). MAIN OUTCOME MEASURES: Feasibility of recruitment and retention (primary outcome), acceptability, and outcome variability over time. RESULTS: We enrolled 24 of 66 cancer survivors approached (36%) and 20 completed follow-up (83%). Key reasons for declining participation included: not interested (n = 18), did not perceive a need (n = 9), and emotional distress/overwhelmed (n = 7). Most participants reported that MAP was acceptable (e.g. 80% liked MAP quite a bit/very much). Exploratory analyses revealed a -4.68 point reduction in fatigue from before to 2 weeks after MAP exceeding a minimally important difference (d = -0.68). There were also improvements in patient autonomy (d = 0.63), self-efficacy (for managing symptoms: d = 0.56, for managing chronic disease: d = 0.44), psychological stress (d = -0.45), anxiety (d = -0.34), sleep disturbance (d = -0.29) and pain (d = -0.32). Qualitative feedback enhanced interpretation of results. CONCLUSIONS: MAP feasibility in colorectal cancer survivors was mixed, predominantly because many patients did not perceive a need for this approach. MAP was acceptable among participants and showed promise for improving health outcomes.

Adaptation of a Personalized Electronic Care Planning Tool for Cancer Follow-up Care: Formative Study.

BACKGROUND: Most patients diagnosed with colorectal cancer will survive for at least 5 years; thus, engaging patients to optimize their health will likely improve outcomes. Clinical guidelines recommend patients receive a comprehensive care plan (CP) when transitioning from active treatment to survivorship, which includes support for ongoing symptoms and recommended healthy behaviors. Yet, cancer care providers find this guideline difficult to implement. Future directions for survivorship care planning include enhancing information technology support for developing personalized CPs, using CPs to facilitate self-management, and assessing CPs in clinical settings. OBJECTIVE: We aimed to develop an electronic tool for colorectal cancer follow-up care (CFC) planning. METHODS: Incorporating inputs from health care professionals and patient stakeholders is fundamental to the successful integration of any tool into the clinical workflow. Thus, we followed the Integrate, Design, Assess, and Share (IDEAS) framework to adapt an existing application for stroke care planning (COMPASS-CP) to meet the needs of colorectal cancer survivors (COMPASS-CP CFC). Constructs from the Consolidated Framework for Implementation Research (CFIR) guided our approach. We completed this work in 3 phases: (1) gathering qualitative feedback from stakeholders about the follow-up CP generation design and workflow; (2) adapting algorithms and resource data sources needed to generate a follow-up CP; and (3) optimizing the usability of the adapted prototype of COMPASS-CP CFC. We also quantitatively measured usability (target average score ≥70; range 0-100), acceptability, appropriateness, and feasibility. RESULTS: In the first phase, health care professionals (n=7), and patients and caregivers (n=7) provided qualitative feedback on COMPASS-CP CFC that informed design elements such as selection, interpretation, and clinical usefulness of patient-reported measures. In phase 2, we built a minimal viable product of COMPASS-CP CFC. This tool generated CPs based on the needs identified by patient-completed measures (including validated patient-reported outcomes) and electronic health record data, which were then matched with resources by zip code and preference to support patients' self-management. Elements of the CFIR assessed revealed that most health care professionals believed the tool would serve patients' needs and had advantages. In phase 3, the average System Usability Scale score was above our target score for health care professionals (n=5; mean 71.0, SD 15.2) and patients (n=5; mean 95.5, SD 2.1). Participants also reported high levels of acceptability, appropriateness, and feasibility. Additional CFIR-informed feedback, such as desired format for training, will inform future studies. CONCLUSIONS: The data collected in this study support the initial usability of COMPASS-CP CFC and will inform the next steps for implementation in clinical care. COMPASS-CP CFC has the potential to streamline the implementation of personalized CFC planning to enable systematic access to resources that will support self-management. Future research is needed to test the impact of COMPASS-CP CFC on patient health outcomes.

Regulator of Chromosome Condensation (RCC1) a novel therapeutic target in pancreatic ductal adenocarcinoma drives tumor progression via the c-Myc-RCC1-Ran axis.

Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal malignancy with limited therapeutic options. Here we for the first time evaluated the role of regulator of chromosome condensation 1 (RCC1) in PDAC subsistence and drug resistance. RCC1 expression was found to be elevated in PDAC tissues in comparison with normal pancreatic tissues and was linked to poor prognosis. RCC1 silencing in a panel of PDAC cells by RNA interference and CRISPR-Cas9 resulted in reduced cellular proliferation in 2D and 3D cultures. RCC1 KD reduced migratory and clonogenic ability, enhanced apoptosis, and altered cell cycle distribution in human PDAC cells as well as cells isolated from the LSL-Kras G12D/+; LSL-Trp53 R172H/+ ;Pdx1-Cre (KPC) mouse tumors. Subcutaneous cell-derived xenografts show significantly attenuated growth of RCC1 KO tumors. Mechanistically, RCC1 knockdown resulted in disruption of subcellular Ran distribution indicating that stable nuclear Ran localization is critical for PDAC proliferation. Nuclear and cytosolic proteomic analysis revealed altered subcellular proteome in RCC1 KD KPC-tumor-derived cells. Altered cytoplasmic protein pathways include several metabolic pathways and PI3K-Akt signaling pathway. Pathways enriched in altered nuclear proteins include cell cycle, mitosis, and RNA regulation. RNA sequencing of RCC1 KO cells showed widespread transcriptional alterations. Upstream of RCC1, c-Myc activates the RCC1-Ran axis, and RCC1 KO enhances the sensitivity of PDAC cells to c-Myc inhibitors. Finally, RCC1 knockdown resulted in the sensitization of PDAC cells to Gemcitabine. Our results indicate that RCC1 is a potential therapeutic target in PDAC that warrants further clinical investigations.

TGFBR1 signaling and breast cancer.

Over the past decade mutations discovered in genes such as BRCA1, BRCA2, TP53 and PTEN, have emerged as high-penetrance susceptibility genes and are clinically relevant for determination of breast cancer risk. Genetic counseling and subsequent screening for mutations and gene rearrangement has improved patient outcome through early detection and prophylactic interventions in patients with familial breast cancer syndromes. However, these high-penetrance genes only account for a small fraction of the hereditary linked breast cancers. It is currently believed that low-penetrance susceptibility alleles and/or environmental factors may play an important role in the remaining cases. TGFBR1*6A (*6A) is a common hypomorphic variant of the type I TGF-ß receptor gene (TGFBR1) that has been associated with risk for several forms of cancer, in particular breast cancer. Several epidemiological studies have suggested that patients who carry the *6A allele have an increased risk of breast cancer. Furthermore, functional analysis suggests that this mutation alters TGF-ß signaling and promotes tumorigenesis. Although a decade of research has provided basic information in regards to the prevalence of this mutation in several cancer types and populations the molecular underpinning of its functional effects are poorly understood. A better understanding of the molecular mechanism of TGFBR1 signaling in breast cancer may have an impact on breast cancer risk assessment and breast cancer prevention.