HA-1-targeted T cell receptor (TCR) T cell therapy for recurrent leukemia after hematopoietic stem cell transplantation

Relapse is the leading cause of death after allogeneic hematopoietic stem cell transplantation (HCT) for leukemia. T cells engineered by gene transfer to express T cell receptors (TCR; TCR-T) specific for hematopoietic-restricted minor histocompatibility (H) antigens may provide a potent selective anti-leukemic effect post-HCT. We conducted a phase I clinical trial employing a novel TCR-T product targeting the minor H antigen HA-1 to treat or consolidate treatment of persistent or recurrent leukemia and myeloid neoplasms. The primary objective was to evaluate the feasibility and safety of administration of HA-1 TCR-T post-HCT. CD8+ and CD4+ T cells expressing the HA-1 TCR and a CD8-co-receptor were successfully manufactured from HA-1 disparate HCT donors. One or more infusions of HA-1 TCR-T following lymphodepleting chemotherapy were administered to nine HCT recipients who had developed disease recurrence post-HCT. TCR-T cells expanded and persisted in vivo after adoptive transfer. No dose-limiting toxicities occurred. Although the study was not designed to assess efficacy, four patients achieved or maintained complete remissions following lymphodepletion and HA-1 TCR-T, with one ongoing at >2 years. Single-cell RNA sequencing of relapsing/progressive leukemia after TCR-T therapy identified upregulated molecules associated with T cell dysfunction or cancer cell survival. HA-1 TCR-T therapy appears feasible and safe and shows preliminary signals of efficacy. This clinical trial is registered at clinicaltrials.gov as NCT03326921.

Revisiting the Utility of Granulocyte Colony-Stimulating Factor Post-Autologous Hematopoietic Stem Cell Transplantation for Outpatient-Based Transplantations

The use of granulocyte colony-stimulating factor (G-CSF) after autologous stem cell transplantation (ASCT) has been shown to reduce the time to neutrophil engraftment, as well as the duration of hospitalization post-transplantation. However, prior studies have focused on inpatient-based ASCT, where patients are routinely admitted for conditioning and frequently remain hospitalized until signs of neutrophil recovery. Given improvements in post-transplantation care, an increasing number of patients, particularly those receiving ASCT for multiple myeloma, are now undergoing transplantation in an outpatient setting. We hypothesized that the routine use of G-CSF for outpatient-based ASCT might not result in the same benefit with respect to a reduced duration of hospitalization and thus should be reconsidered in this setting. We performed a retrospective cohort study of 633 consecutive patients with multiple myeloma (MM; n = 484) or non-Hodgkin lymphoma (NHL; n = 149) who underwent ASCT between September 2018 and February 2023. Outpatient ASCT comprised 258 (53%) of combined MM and NHL cases. Starting in September 2021, post-transplantation G-CSF was incorporated into the supportive care regimen for all ASCTs. A total of 410 patients (309 with MM, 101 with NHL) underwent ASCT during the pre-G-CSF policy period and 223 (175 with MM, 48 with NHL) did so in the post-G-CSF policy period. The primary outcome focused on the duration of hospitalization within the first 30 days following graft infusion. As expected, after implementation of the G-CSF policy, the time to neutrophil engraftment was reduced in the patients with MM (mean, -2.8 days; P < .0001) and patients with NHL (mean, -2.9 days; P < .0001). However, among the patients with MM, roughly one-half of whom underwent outpatient-based ASCT, the inpatient duration during the first 30 days was not reduced after G-CSF implementation (P = .40). Comparatively, the inpatient duration (mean, -1.8 days; P = .030) was reduced among patients with NHL, all of whom were electively admitted for ASCT. For patients with MM at an outpatient-based transplant center, incorporation of G-CSF post-ASCT resulted in reduced time to neutrophil engraftment but did not significantly reduce the time spent in the inpatient setting through day +30.

Intestinal microbiota controls graft-versus-host disease independent of donor-host genetic disparity

Acute graft-versus-host disease (aGVHD) remains a major limitation of allogeneic stem cell transplantation (SCT), and severe intestinal manifestation is the major cause of early mortality. Intestinal microbiota control MHC class II (MHC-II) expression by ileal intestinal epithelial cells (IECs) that promote GVHD. Here, we demonstrated that genetically identical mice of differing vendor origins had markedly different intestinal microbiota and ileal MHC-II expression, resulting in discordant GVHD severity. We utilized cohousing and antibiotic treatment to characterize the bacterial taxa positively and negatively associated with MHC-II expression. A large proportion of bacterial MHC-II inducers were vancomycin sensitive, and peri-transplant oral vancomycin administration attenuated CD4+ T cell-mediated GVHD. We identified a similar relationship between pre-transplant microbes, HLA class II expression, and both GVHD and mortality in a large clinical SCT cohort. These data highlight therapeutically tractable mechanisms by which pre-transplant microbial taxa contribute to GVHD independently of genetic disparity.

Late Effects of Severe Acute Graft-versus-Host Disease on Quality of Life, Medical Comorbidities, and Survival

Grade III-IV acute graft-versus-host disease (aGVHD) is associated with high short-term morbidity and mortality following allogeneic hematopoietic cell transplantation (HCT). The long-term effects after recovery from grade III-IV aGVHD are unknown. This study aimed to analyze late medical comorbidities, quality of life, nonrelapse mortality, and survival in patients treated for grade III-IV aGVHD. Chart review identified late effects, and patients were asked to complete annual surveys to collect patient-reported outcomes. Outcomes were compared between patients with grade 0-I aGVHD and grade III-IV aGVHD who underwent HCT between 2001 and 2019 and survived for at least 1 year post-transplantation. Patients with a history of grade III-IV aGVHD (n = 192) had significantly higher rates of late medical comorbidities (P < .001) and worse physical (P = .01) and mental (P = .04) functioning compared with patients with grade 0-I aGVHD (n = 615). Patients who survived for >1 year post-transplantation and had prior grade III-IV aGVHD also had worse 5-year overall survival (77.5% versus 83.6%; P = .006) and higher nonrelapse mortality (19.2% versus 10.6%; P < .001) compared with those with a history of grade 0-I aGVHD. No between-group difference was found in cumulative incidence of chronic GVHD. Patients who recover from severe aGVHD remain vulnerable to developing late comorbidities. These patients would likely benefit from continued monitoring and supportive care in an attempt to prevent late effects and improve survival.

CMV exposure drives long-term CD57+ CD4 memory T-cell inflation following allogeneic stem cell transplant

Donor and recipient cytomegalovirus (CMV) serostatus correlate with transplant-related mortality that is associated with reduced survival following allogeneic stem cell transplant (SCT). Prior epidemiologic studies have suggested that CMV seronegative recipients (R-) receiving a CMV-seropositive graft (D+) experience inferior outcomes compared with other serostatus combinations, an observation that appears independent of viral reactivation. We therefore investigated the hypothesis that prior donor CMV exposure irreversibly modifies immunologic function after SCT. We identified a CD4+/CD57+/CD27- T-cell subset that was differentially expressed between D+ and D- transplants and validated results with 120 patient samples. This T-cell subset represents an average of 2.9% (D-/R-), 18% (D-/R+), 12% (D+/R-), and 19.6% (D+/R+) (P < .0001) of the total CD4+ T-cell compartment and stably persists for at least several years post-SCT. Even in the absence of CMV reactivation post-SCT, D+/R- transplants displayed a significant enrichment of these cells compared with D-/R- transplants (P = .0078). These are effector memory cells (CCR7-/CD45RA+/-) that express T-bet, Eomesodermin, granzyme B, secrete Th1 cytokines, and are enriched in CMV-specific T cells. These cells are associated with decreased T-cell receptor diversity (P < .0001) and reduced proportions of major histocompatibility class (MHC) II expressing classical monocytes (P < .0001), myeloid (P = .024), and plasmacytoid dendritic cells (P = .0014). These data describe a highly expanded CD4+ T-cell population and putative mechanisms by which prior donor or recipient CMV exposure may create a lasting immunologic imprint following SCT, providing a rationale for using D- grafts for R- transplant recipients.

Utilization of COVID-19 Treatments and Clinical Outcomes among Patients with Cancer: A COVID-19 and Cancer Consortium (CCC19) Cohort Study

Among 2,186 U.S. adults with invasive cancer and laboratory-confirmed SARS-CoV-2 infection, we examined the association of COVID-19 treatments with 30-day all-cause mortality and factors associated with treatment. Logistic regression with multiple adjustments (e.g., comorbidities, cancer status, baseline COVID-19 severity) was performed. Hydroxychloroquine with any other drug was associated with increased mortality versus treatment with any COVID-19 treatment other than hydroxychloroquine or untreated controls; this association was not present with hydroxychloroquine alone. Remdesivir had numerically reduced mortality versus untreated controls that did not reach statistical significance. Baseline COVID-19 severity was strongly associated with receipt of any treatment. Black patients were approximately half as likely to receive remdesivir as white patients. Although observational studies can be limited by potential unmeasured confounding, our findings add to the emerging understanding of patterns of care for patients with cancer and COVID-19 and support evaluation of emerging treatments through inclusive prospective controlled trials. SIGNIFICANCE: Evaluating the potential role of COVID-19 treatments in patients with cancer in a large observational study, there was no statistically significant 30-day all-cause mortality benefit with hydroxychloroquine or high-dose corticosteroids alone or in combination; remdesivir showed potential benefit. Treatment receipt reflects clinical decision-making and suggests disparities in medication access.This article is highlighted in the In This Issue feature, p. 1426.

Steroid-Refractory Autoimmune Myocarditis after Pembrolizumab Therapy: Failure of Equine Anti-Thymocyte Globulin to Prevent Heart Failure

While immune checkpoint inhibitors (ICIs) are improving outcomes for many cancers, they can have severe adverse effects. Though cardiac immune-related adverse effects (irAEs) are rare, they have considerable morbidity and mortality. Prior case studies have demonstrated successful treatment of ICI induced autoimmune myocarditis with a variety of immunosuppressive regimens. This case describes steroid-refractory autoimmune myocarditis after treatment with pembrolizumab. Treatment with equine anti-thymocyte globulin, a regimen previously documented to reverse ICI induced autoimmune myocarditis, temporarily improved clinical status and cardiac biomarkers, however eventually failed to prevent progression to heart failure and cardiovascular death. This case highlights the importance of early stress-dose steroids, identifies troponin as a potential marker of treatment response, and underscores the value of collaboration between oncology and cardiology for optimal management.

Hematopoietic Stem-Cell Transplantation in the Resource-Limited Setting: Establishing the First Bone Marrow Transplantation Unit in Bangladesh

PURPOSE

Treatment of malignant and nonmalignant hematologic diseases with hematopoietic stem-cell transplantation (HSCT) was first described almost 60 years ago, and its use has expanded significantly over the last 20 years. Whereas HSCT has become the standard of care for many patients in developed countries, the significant economic investment, infrastructure, and health care provider training that are required to provide such a service have prohibited it from being widely adopted, particularly in developing countries.

METHODS

Over the past two decades, however, efforts to bring HSCT to the developing world have increased, and several institutions have described their efforts to establish such a program. We aim to provide an overview of the current challenges and applications of HSCT in developing countries as well as to describe our experience in developing an HSCT program at Dhaka Medical College and Hospital in Bangladesh via a partnership with health care providers at Massachusetts General Hospital.

RESULTS AND CONCLUSION

We discuss key steps of the program, including the formation of a collaborative partnership, infrastructure development, human resource capacity building, and financial considerations.

Building Specialized Nursing Practice Capacity in Bangladesh: An Educational Program to Prepare Nurses to Care for Oncology and Bone Marrow Transplant Patients in Dhaka, Bangladesh

In 2012, the Minister of Health and other leaders in the Bangladesh government approached Massachusetts General Hospital to establish the country’s first bone marrow transplant program at Dhaka Medical College Hospital to serve the needs of the people of Bangladesh. Stated goals of this collaboration included a broad focus on the care of oncology patients with a specific emphasis on care of patients with hematologic malignancies and of women with gynecologic cancers. The purpose of this article is to describe the international nursing collaboration between Massachusetts General Hospital, Simmons College, the AK Khan Healthcare Trust in Dhaka, and Dhaka Medical College Hospital that was established to share nursing knowledge and to build specialized professional nursing capacities to deliver high-quality cancer care in the public sector. Over the past 3 years, through the educational programs that have been developed within this collaboration—the Enhanced Specialized Nurse Training Program—the Bangladeshi nurses have received continuing professional development based on Western standards of nursing and have been offering nursing care to patients who have undergone chemotherapy and bone marrow transplantation. The challenges, opportunities, and outcomes of this international collaboration have been highly rewarding and mutually beneficial.

AKT1low Quiescent Cancer Cells Promote Solid Tumor Growth

Human tumor growth depends on rapidly dividing cancer cells driving population expansion. Even advanced tumors, however, contain slowly proliferating cancer cells for reasons that remain unclear. Here, we selectively disrupt the ability of rapidly proliferating cancer cells to spawn AKT1^low daughter cells that are rare, slowly proliferating, tumor-initiating, and chemotherapy-resistant, using β1-integrin activation and the AKT1-E17K-mutant oncoprotein as experimental tools in vivo Surprisingly, we find that selective depletion of AKT1^low slow proliferators actually reduces the growth of a molecularly diverse panel of human cancer cell xenograft models without globally altering cell proliferation or survival in vivo Moreover, we find that unusual cancer patients with AKT1-E17K-mutant solid tumors also fail to produce AKT1^low quiescent cancer cells and that this correlates with significantly prolonged survival after adjuvant treatment compared with other patients. These findings support a model whereby human solid tumor growth depends on not only rapidly proliferating cancer cells but also on the continuous production of AKT1^low slow proliferators. Mol Cancer Ther; 17(1); 254-63. ©2017 AACR.

Abstract 717: Diagnosis of basal like breast cancer using DNA methylation markers at the promoters of long noncoding RNAs

Background: Patients with basal-like breast cancer (BLBC) have poor overall survival and suffer a high rate of metastasis to the brain or lung within three to five years of initial presentation. Absence of a cure for advanced BLBC warrants early detection of BLBC, which might save more lives, especially those of women of African ancestry who are disproportionately affected by young onset BLBC. Aberrant DNA methylation is frequently observed in BLBC. DNA methylation is the most robust epigenetic marks and can be analyzed using clinical specimens including FFPE, tumor biopsies and liquid biopsies. Because expression of long non-coding RNAs (lncRNAs) is controlled temporally in response to neoplastic stimuli, we investigated the potential for lncRNA promoter methylation marks to be used for detection and prediction of BLBC development and progression in African Americans.

Methods: To identify lncRNAs dysregulated in BLBC, we performed a Ribo-Zero RNA-seq or microarray analysis on breast tissues isolated from African American (n=63) and European American patients (n=14). Differentially methylated and hydroxymethylated regions of lncRNA genes were identified in African American samples (n=30) using our chemical methods to assay 5-methylcytosine (5mC) and 5-hydroxymethylcytosine (5hmC). The Cancer Genome Atlas (TCGA) datasets were utilized to validate our results. To functionally annotate lncRNAs, we knocked down lncRNAs using LNA-antisense oligonucleotides (ASO) and performed Caspase 3/7 assays, flow cytometry, and qRT-PCR. We also utilized the CRISPR-Cas9 editing tools to knock out lncRNAs.

Results: LncRNAs displayed distinct expression patterns between tumors and normal breast tissues. Out of hundreds of lncRNAs specifically expressed in BLBC tumors, we selected two lncRNAs, lnc19 and lnc98, which represent, respectively, a significantly increased and decreased lncRNA in BLBC tumors, compared to normal breast tissues and other subtype tumors. Lnc19 is highly up-regulated (a 39-fold increase) whereas lnc98 is dramatically down-regulated (a 59-fold decrease) in BLBC tumors. Methylation analysis showed significantly lower levels of promoter methylation for lnc19 and higher levels for lnc98 in BLBC tumors. A significant inverse correlation between methylation and expression of lnc19 was observed. Depletion of lnc19 resulted in rapid cell death of BLBC cells, with increased sensitivity to chemotherapy drugs. The data suggests that chemo-resistance of BLBC might be partly due to lnc19 overexpression, which is mediated through epigenetic control.

Conclusion: We identified two epigenetically dysregulated lncRNAs in BLBC tumors, which contribute to chemo-resistance of these tumors. Our findings on the regulation of lncRNAs by cytosine methylation raise the possibility of new epigenetic biomarkers for diagnosis and prognosis of aggressive BLBC tumors.

Citation Format: Yoo J. Han, Sonja M. Boatman, Jing Zhang, Albert C. Yeh, Yonglan Zheng, Olufunmilayo I. Olopade. Diagnosis of basal like breast cancer using DNA methylation markers at the promoters of long noncoding RNAs [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 717. doi:10.1158/1538-7445.AM2017-717

Abstract P3-07-08: Molecular subtype-specific expression of long noncoding RNA regulates proliferation of basal-like breast cancer cells

Background: Basal-like breast cancer (BLBC) disproportionally affects younger women and African American women, displaying aggressive clinical behavior with poor outcomes. BLBC is difficult to treat due to its lack of defined molecular targets, and with current treatment, patients often develop metastatic disease. A growing body of evidence points to long noncoding (lnc) RNAs as mediators of tumor progression, suggesting a new class of targets in cancer therapy. While dynamic changes in lncRNA expression are observed across many types of cancer, our understanding of their role in cancer biology is limited. The aim of this study is to identify lncRNAs differentially expressed in BLBC and to characterize the functional features of candidate lncRNA.

Methods: Breast tumors and normal breast tissues were recruited from the U of Chicago Breast Cancer Tissue Bank under IRB approved protocols. Microarray profiling was done using Human LncRNA Array v3 (Arraystar) containing 30,586 lncRNAs and 26,109 mRNAs. Non-poly(A) RNAs were included with ribo-zero RNA-seq (Illumina HiSeq 4000). Molecular subtype of breast tumors was determined by PAM50 intrinsic classifier. In addition, CpG methylation of lncRNA promoter regions was analyzed with TCGA HumanMethylation450 Array data from 588 breast tissues. We performed in vitro studies using antisense oligonucleotide (ASO) knockdown and CRISPR-on overexpression in BLBC cell lines. Phenotypic consequences of perturbations of specific lncRNA expression were assessed using proliferation, apoptosis, cell cycle and homologous recombination assays.

Results: Microarray profiling of breast tissues from 30 African American women revealed a unique lncRNA signature in basal-like tumors compared to non-basal like tumors. Hundreds of lncRNAs were specifically expressed in BLBC, with &gt;100-fold differences in some lncRNAs compared to tumors from other subtypes or normal breast tissues. Through statistical and in silico analyses we selected lncRNAs displaying increased expression in basal-like tumors (vs non-basal tumors) and BLBC cell lines (vs non-basal cell lines) with a trend of higher expression in cells isolated from women of African ancestry for functional studies. RNA-seq of 50 additional breast tissues recapitulated the distinct lncRNA clustering within the basal-like subtype. TCGA analysis of CpG islands in several lncRNA promoter regions revealed hypo-methylation when compared to non-BLBC, signifying subtype specific epigenetic regulation. ASO knockdown of candidate lncRNAs significantly increased apoptosis and decreased proliferation while CRISPR-on overexpression decreased cell sensitivity to doxorubicin treatment. Depletion of specific lncRNAs caused an increased proportion of cells in G2 phase of the cell cycle, indicating that overexpression of particular lncRNAs may contribute to aberrant cell cycle progression. Cis and trans-regulation of gene expression by lncRNAs is currently under investigation through RNA immunoprecipitation and genome-wide gene expression profiling.

Conclusion: We propose that subtype specific lncRNAs function as onco-RNAs specific to BLBC, driving cellular proliferation and increasing resistance to DNA damaging chemotherapies through regulation of the cell cycle.

Citation Format: Boatman SM, Han Y-J, Zhang J, Zheng Y, Yeh AC, Olopade OI. Molecular subtype-specific expression of long noncoding RNA regulates proliferation of basal-like breast cancer cells [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P3-07-08.

Abstract 2633: Radiogenomics of breast cancer using DCE-MRI and gene expression profiling

The utilization of radiomics (high-throughput extraction and analysis of imaging features) to abstract underlying genomic features of an evolving malignancy is an emerging field that has the potential to detail biological information of a tumor in a non-invasive and more accessible manner. Furthermore, applying radiomics confers a comprehensive spatial view of the tumor, a potential advantage over the limitations of sampling a small region of tissue that may not accurately represent the underlying complexity of the entire tumor. Most studies to date that incorporate radiogenomics in the analysis of breast cancers have focused on few basic clinical data or individual genetic mutations such as BRCA or HER2 status.

Here, we use an automated quantitative radiomics analysis platform developed at the University of Chicago that enables computerized feature extraction of tumors to analyze magnetic resonant imaging scans of 50 breast cancer patients (mean age of diagnosis [range]: 54 [24-89]; receptor status: HER2+: 14, Triple negative: 7; stage [1 through 4]: 10%, 40%, 42%, 8%) who have had comprehensive gene expression profiling performed using Agilent Human Gene Expression arrays. Our imaging platform extracts 38 features across six major phenotypes (size, shape, morphology, enhancement texture, kinetic curve assessment, and enhancement variance kinetics) (see Table for listing of 24 selected features). Existing radiomic analysis derived from a TCGA/TCIA dataset suggests that there are many correlations between imaging phenotypes and various genetic pathways, such as VEGF signaling and volume of enhancing voxels, base excision repair and enhancement texture entropy, and TGF-beta signaling and enhancement texture variance. We confirm these relationships as well as establish novel associations using a robust imaging dataset. By associating specific radiomic features with gene expression profile of tumors, we have the opportunity to extract detailed biological information non-invasively through clinical imaging. Selected imaging phenotypes extracted from MRI scansPhenotype categoryImage phenotypeDescriptionSizeVolumeVolume of lesionSizeEffective diameterDiameter of a sphere with the same volume as the lesionSizeSurface areaLesion surface areaShapeSphericitySimilarity of the lesion shape to a sphereShapeIrregularityDeviation of the lesion surface from the surface of a sphereShapeSurface area / volumeRatio of surface area to volumeMorphologyMargin sharpnessMean of the image gradient at the lesion marginMorphologyVariance of margin sharpnessVariance of the image gradient at the lesion marginMorphologyVariance of radial gradient histogramDegree to which the enhancement structure extends in a radial pattern originating from the center of the lesionEnhancement TextureContrastLocal image variationsEnhancement TextureEntropyRandomness of the gray-levelsEnhancement TextureDifference varianceVariations of difference of gray-levels between voxel-pairsEnhancement TextureAngular second momentImage homogeneityEnhancement TextureMaximum correlation coefficientNonlinear gray-level dependenceEnhancement TextureSum averageOverall brightnessEnhancement TextureSum of squaresSpread in the gray-level distributionKinetic Curve AssessmentMaximum enhancementMaximum contrast enhancementKinetic Curve AssessmentTime to peakTime at which the maximum enhancement occursKinetic Curve AssessmentUptake rateUptake speed of the contrast enhancementKinetic Curve AssessmentCurve shape indexDifference between late and early enhancementKinetic Curve AssessmentTotal rate variationHow rapidly the contrast will enter and exit from the lesionEnhancement-Variance KineticsMaximum variance of enhancementMaximum spatial variance of contrast enhancement over timeEnhancement-Variance KineticsTime to peak maximum varianceTime at which the maximum variance occursEnhancement-Variance KineticsEnhancement variance increasing rateRate of increase of the enhancement-variance during uptake

Citation Format: Albert C. Yeh, Stephanie McGregor, Hui Li, Yuan Ji, Yitan Zhu, Tatyana Grushko, Alexandra Edwards, Fan Lui, Jing Zhang, Qiu Niu, Yonglan Zheng, Toshio Yoshimatsu, Galina Khramtsova, Karen Drukker, Gregory Karczmar, Hiroyuki Abe, Jeffrey Mueller, Maryellen Giger, Olufunmilayo Olopade. Radiogenomics of breast cancer using DCE-MRI and gene expression profiling. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2633.

Mechanisms of Cancer Cell Dormancy--Another Hallmark of Cancer?

Disease relapse in cancer patients many years after clinical remission, often referred to as cancer dormancy, is well documented but remains an incompletely understood phenomenon on the biologic level. Recent reviews have summarized potential models that can explain this phenomenon, including angiogenic, immunologic, and cellular dormancy. We focus on mechanisms of cellular dormancy as newer biologic insights have enabled better understanding of this process. We provide a historical context, synthesize current advances in the field, and propose a mechanistic framework that treats cancer cell dormancy as a dynamic cell state conferring a fitness advantage to an evolving malignancy under stress. Cellular dormancy appears to be an active process that can be toggled through a variety of signaling mechanisms that ultimately downregulate the RAS/MAPK and PI(3)K/AKT pathways, an ability that is preserved even in cancers that constitutively depend on these pathways for their growth and survival. Just as unbridled proliferation is a key hallmark of cancer, the ability of cancer cells to become quiescent may be critical to evolving malignancies, with implications for understanding cancer initiation, progression, and treatment resistance.

A mechanism for asymmetric cell division resulting in proliferative asynchronicity

All cancers contain an admixture of rapidly and slowly proliferating cancer cells. This proliferative heterogeneity complicates the diagnosis and treatment of patients with cancer because slow proliferators are hard to eradicate, can be difficult to detect, and may cause disease relapse sometimes years after apparently curative treatment. While clonal selection theory explains the presence and evolution of rapid proliferators within cancer cell populations, the circumstances and molecular details of how slow proliferators are produced is not well understood. Here, a β1-integrin/FAK/mTORC2/AKT1-associated signaling pathway is discovered that can be triggered for rapidly proliferating cancer cells to undergo asymmetric cell division and produce slowly proliferating AKT1(low) daughter cells. In addition, evidence indicates that the proliferative output of this signaling cascade involves a proteasome-dependent degradation process mediated by the E3 ubiquitin ligase TTC3. These findings reveal that proliferative heterogeneity within cancer cell populations, in part, is produced through a targetable signaling mechanism, with potential implications for understanding cancer progression, dormancy, and therapeutic resistance.

IMPLICATIONS

These findings provide a deeper understanding of the proliferative heterogeneity that exists in the tumor environment and highlight the importance of designing future therapies against multiple proliferative contexts. VISUAL OVERVIEW: A proposed mechanism for producing slowly proliferating cancer cells. http://mcr.aacrjournals.org/content/early/2015/01/09/1541-7786.MCR-14-0474/F1.large.jpg.

The Kidney Disease Screening and Awareness Program (KDSAP): a novel translatable model for increasing interest in nephrology careers

Despite the increasing prevalence of CKD in the United States, there is a declining interest among United States medical graduates in nephrology as a career choice. Effective programs are needed to generate interest at early educational stages when career choices can be influenced. The Kidney Disease Screening and Awareness Program (KDSAP) is a novel program initiated at Harvard College that increases student knowledge of and interest in kidney health and disease, interest in nephrology career paths, and participation in kidney disease research. This model, built on physician mentoring, kidney screening of underserved populations, direct interactions with kidney patients, and opportunities to participate in kidney research, can be reproduced and translated to other workforce-challenged subspecialties.

Early assessment of a new integrated preclinical musculoskeletal curriculum at a medical school

Increased incidence of musculoskeletal conditions and medical students' deficiencies in musculoskeletal knowledge have been a cause for concern for educators in this field. Findings from a 2005 study conducted at our institution revealed that medical students, despite acknowledging the importance of musculoskeletal education, have inadequate knowledge and skill in this system. In response to these findings, additions to the preclinical musculoskeletal curriculum were designed and instituted. Medical students were assessed at the end of the new curriculum, using the same evaluation tools that had been administered before the curricular changes, and responses from the second-year students who completed the entire new preclinical curriculum were compared with those of students who had completed the old curriculum. Results showed that students reported significantly higher levels of clinical confidence in performing physical examinations of several anatomical regions of the musculoskeletal system. A notable proportion of students cited weaknesses in other fields, such as anatomy, as a prominent contributor to their lack of confidence in the musculoskeletal system.

Impact of clinical electives and residency interest on medical students' education in musculoskeletal medicine

BACKGROUND

Despite the frequency of musculoskeletal conditions seen in a broad spectrum of medical practice, there is compelling evidence that medical schools are inadequately preparing students in this field. We compared medical students across all residency interests with respect to their clinical confidence, cognitive mastery, and perception of education in musculoskeletal medicine.

METHODS

A cross-sectional survey study of third and fourth-year students at Harvard Medical School was conducted during the 2005-2006 academic year. Two hundred and forty-nine of 337 students completed the survey, yielding an overall response rate of 74%. All participants were asked to complete a nationally validated objective examination in musculoskeletal medicine and a thirty-question survey soliciting their top residency choice, all of the musculoskeletal electives that they had taken, their clinical confidence, and their attitudes toward musculoskeletal education.

RESULTS

Residency interest significantly affected the third-year students' performance on the cognitive mastery examination (p = 0.018) and also significantly affected both the third and the fourth-year students' clinical confidence in their ability to perform an examination of the musculoskeletal system (p = 0.023 and p = 0.015, respectively). The students' perception of the importance of musculoskeletal medicine, regardless of their residency interest, correlated with their decision to take musculoskeletal clinical electives (p = 0.009 and p < 0.001 for third and fourth-year students, respectively). Perceived importance was also correlated with higher clinical confidence for third-year students (p = 0.043) and increased examination scores for fourth-year students (p < 0.001). However, only students who listed orthopaedic surgery as their top residency choice demonstrated cognitive mastery in musculoskeletal medicine and reported above-average clinical confidence in their ability to conduct an examination of the musculoskeletal system.

CONCLUSIONS

Students' residency interest and their perception of the importance of musculoskeletal medicine to their future career influence the education that they receive in this field. In particular, students interested in non-orthopaedic residencies failed to demonstrate cognitive mastery and lacked clinical confidence. Possible approaches for medical schools to tackle this important issue that merit further exploration include requiring additional time for education in musculoskeletal medicine and providing a more structured musculoskeletal curriculum.

Musculoskeletal medicine: an assessment of the attitudes and knowledge of medical students at Harvard Medical School

PURPOSE

To assess medical students' knowledge and clinical confidence in musculoskeletal medicine as well as their attitudes toward the education they receive in this specialty.

METHOD

A cross-sectional survey of students in all four years of Harvard Medical School was conducted during the 2005-2006 academic year. Participants were asked to fill out a 30-question survey and a nationally validated basic competency exam in musculoskeletal medicine.

RESULTS

The response rate was 74% (449/608). Medical students rated musculoskeletal education to be of major importance (3.8/5) but rated the amount of curriculum time spent on musculoskeletal medicine as poor (2.1/5). Third-year students felt a low to adequate level of confidence in performing a musculoskeletal physical examination (2.7/5) and failed to demonstrate cognitive mastery in musculoskeletal medicine (passing rate on competency exam: 7%), whereas fourth-year students reported a similar level of confidence (2.7/5) and exhibited a higher passing rate (26%). Increasing exposure to the subject by taking clinical electives resulted in greater clinical confidence and enhanced performance on the exam (P < .001). Students' feedback suggested that musculoskeletal education can be better integrated into the preclinical curriculum, more time should be spent in the field, and more focus should be placed on common clinical conditions.

CONCLUSIONS

These findings, which are consistent with those from other schools, suggest that medical students do not feel adequately prepared in musculoskeletal medicine and lack both clinical confidence and cognitive mastery in the field. Implementing a four-year integrated musculoskeletal curriculum is one way that medical schools can address this concern.