Dual-energy subtraction radiography (DESR): a systematic review and meta-analysis of pulmonary nodule detection

PURPOSE

This study examined the literature to compare the accuracy, sensitivity, and specificity of dual-energy subtraction radiography (DESR) with conventional radiography (CR) in the detection of pulmonary nodules. To our knowledge, no meta-analysis has been conducted to compare DESR with CR.

MATERIAL AND METHODS

The authors searched Pubmed using the terms "Dual-energy subtraction radiography," and "Dual-Energy Chest Radiography." Only studies comparing the detection of pulmonary nodules between DESR and CR were included. Studies utilizing artificial intelligence were excluded. The primary study outcomes analyzed were the mean difference of receiver operating characteristic area under the curve (ROC AUC), mean difference of sensitivity, and mean difference of specificity.

RESULTS

Twenty-three studies between 1994 and 2022 were included. Of these twenty-three, eighteen reported ROC AUC statistics. The difference between DESR ROC AUC (mean = 0.7702, SD = 0.1361) and CR ROC AUC (mean = 0.7106, SD = 0.1183) was 0.0597 (P<0.001). Sensitivity data was reported for thirteen of the twenty-three selected studies. The difference between DESR sensitivity (mean = 0.5753, SD = 0.1546) and CR sensitivity (mean = 0.4391, SD = 0.1007) was 0.136 (P<0.001). Specificity data were reported for ten of the twenty-three selected studies. The difference between DESR specificity (mean = 0.753, SD = 0.1575) and CR specificity (mean = 0.764, SD = 0.1168) was -0.011 (P=0.767). This was not statistically significant.

CONCLUSIONS

DESR showed superior sensitivity and ROC AUC values compared with CR in detecting pulmonary nodules. There was no difference in specificity.

Pre-onset subthreshold psychotic symptoms are associated with differential treatment delays before a first episode of psychosis: Initial evidence and implications

BACKGROUND

Help-seeking and treatment delays are increasingly critical areas of study in mental health services. The duration of untreated psychosis (DUP), or the time between illness onset and initiation of treatment, is a predictor of symptom remission and functioning for a first episode of psychosis (FEP). The World Health Organization recommends that specialized treatment for psychosis be initiated within the first three months of FEP onset. As a result, research has focused on factors that are associated with threshold-level DUP, while the experience of subthreshold psychotic symptoms (STPS) prior to a FEP may also complicate and present barriers to accessing care for young people. We therefore examine the possibility that STPS can impact DUP and its components.

METHOD

Using a follow-back cross-sectional design, we sought to describe duration of untreated illness, length of prodrome, DUP, help-seeking delay, referral delay, and number of help-seeking contacts among FEP patients who did and did not have STPS prior to psychosis onset.

RESULTS

We found that patients who experienced STPS had a longer median duration of untreated illness, prodrome length, DUP, and help-seeking delay compared to patients who did not have such symptoms. Referral delay did not differ substantially between the two groups. Importantly, treatment delays were extremely lengthy for many participants.

CONCLUSIONS

Pre-onset STPS are associated with help-seeking delays along the pathway to care even during a FEP. Examining early signs and symptoms may help to improve and tailor interventions aimed at reducing treatment delays and ultimately providing timely care when the need arises.

Cancer-associated mesothelial cells are regulated by the anti-Müllerian hormone axis

Cancer-associated mesothelial cells (CAMCs) in the tumor microenvironment are thought to promote growth and immune evasion. We find that, in mouse and human ovarian tumors, cancer cells express anti-Müllerian hormone (AMH) while CAMCs express its receptor AMHR2, suggesting a paracrine axis. Factors secreted by cancer cells induce AMHR2 expression during their reprogramming into CAMCs in mouse and human in vitro models. Overexpression of AMHR2 in the Met5a mesothelial cell line is sufficient to induce expression of immunosuppressive cytokines and growth factors that stimulate ovarian cancer cell growth in an AMH-dependent way. Finally, syngeneic cancer cells implanted in transgenic mice with Amhr2-/- CAMCs grow significantly slower than in wild-type hosts. The cytokine profile of Amhr2-/- tumor-bearing mice is altered and their tumors express less immune checkpoint markers programmed-cell-death 1 (PD1) and cytotoxic T lymphocyte-associated protein 4 (CTLA4). Taken together, these data suggest that the AMH/AMHR2 axis plays a critical role in regulating the pro-tumoral function of CAMCs in ovarian cancer.

Signaling pathways and regulation of gene expression in hematopoietic cells

Cellular functions are regulated by signal transduction pathway networks consisting of protein-modifying enzymes that control the activity of many downstream proteins. Protein kinases and phosphatases regulate gene expression by reversible phosphorylation of transcriptional factors, which are their direct substrates. Casein kinase II (CK2) is a serine/threonine kinase that phosphorylates a large number of proteins that have critical roles in cellular proliferation, metabolism and survival. Altered function of CK2 has been associated with malignant transformation, immunological disorders and other types of diseases. Protein phosphatase 1 (PP1) is a serine/threonine phosphatase, which regulates the phosphorylation status of many proteins that are essential for cellular functions. IKAROS is a DNA-binding protein, which functions as a regulator of gene transcription in hematopoietic cells. CK2 directly phosphorylates IKAROS at multiple phosphosites which determines IKAROS activity as a regulator of gene expression. PP1 binds to IKAROS via the PP1-consensus recognition site and dephosphorylates serine/threonine residues that are phosphorylated by CK2. Thus, the interplay between CK2 and PP1 signaling pathways have opposing effects on the phosphorylation status of their mutual substrate - IKAROS. This review summarizes the effects of CK2 and PP1 on IKAROS role in regulation of gene expression and its function as a tumor suppressor in leukemia.

Ensemble GaAsSb/GaAs axial configured nanowire-based separate absorption, charge, and multiplication avalanche near-infrared photodetectors

In this study, molecular beam epitaxially grown axially configured ensemble GaAsSb/GaAs separate absorption, charge, and multiplication (SACM) region-based nanowire avalanche photodetector device on non-patterned Si substrate is presented. Our device exhibits a low breakdown voltage (V _BR) of ∼ -10 ± 2.5 V under dark, photocurrent gain (M) varying from 20 in linear mode to avalanche gain of 700 at V _BR at a 1.064 μm wavelength. Positive temperature dependence of breakdown voltage ∼ 12.6 mV K^-1 further affirms avalanche breakdown as the gain mechanism in our SACM NW APDs. Capacitance-voltage (C-V) and temperature-dependent noise characteristics also validated punch-through voltage ascertained from I-V measurements, and avalanche being the dominant gain mechanism in the APDs. The ensemble SACM NW APD device demonstrated a broad spectral room temperature response with a cut-off wavelength of ∼1.2 μm with a responsivity of ∼0.17-0.38 A W^-1 at -3 V. This work offers a potential pathway toward realizing tunable nanowire-based avalanche photodetectors compatible with traditional Si technology.

The ECHELON-2 Trial: 5-year results of a randomized, phase III study of brentuximab vedotin with chemotherapy for CD30-positive peripheral T-cell lymphoma

BACKGROUND

For patients with peripheral T-cell lymphoma (PTCL), outcomes using frontline treatment with cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) or CHOP-like therapy are typically poor. The ECHELON-2 study demonstrated that brentuximab vedotin plus cyclophosphamide, doxorubicin, and prednisone (A+CHP) exhibited statistically superior progression-free survival (PFS) per independent central review and improvements in overall survival versus CHOP for the frontline treatment of patients with systemic anaplastic large cell lymphoma or other CD30-positive PTCL.

PATIENTS AND METHODS

ECHELON-2 is a double-blind, double-dummy, randomized, placebo-controlled, active-comparator phase III study. We present an exploratory update of the ECHELON-2 study, including an analysis of 5-year PFS per investigator in the intent-to-treat analysis group.

RESULTS

A total of 452 patients were randomized (1 : 1) to six or eight cycles of A+CHP (N = 226) or CHOP (N = 226). At median follow-up of 47.6 months, 5-year PFS rates were 51.4% [95% confidence interval (CI): 42.8% to 59.4%] with A+CHP versus 43.0% (95% CI: 35.8% to 50.0%) with CHOP (hazard ratio = 0.70; 95% CI: 0.53-0.91), and 5-year overall survival (OS) rates were 70.1% (95% CI: 63.3% to 75.9%) with A+CHP versus 61.0% (95% CI: 54.0% to 67.3%) with CHOP (hazard ratio = 0.72; 95% CI: 0.53-0.99). Both PFS and OS were generally consistent across key subgroups. Peripheral neuropathy was resolved or improved in 72% (84/117) of patients in the A+CHP arm and 78% (97/124) in the CHOP arm. Among patients who relapsed and subsequently received brentuximab vedotin, the objective response rate was 59% with brentuximab vedotin retreatment after A+CHP and 50% with subsequent brentuximab vedotin after CHOP.

CONCLUSIONS

In this 5-year update of ECHELON-2, frontline treatment of patients with PTCL with A+CHP continues to provide clinically meaningful improvement in PFS and OS versus CHOP, with a manageable safety profile, including continued resolution or improvement of peripheral neuropathy.

Are we overtreating patients with malignant colorectal polyps? A 5-year review of the ACPGBI position statement

INTRODUCTION

In 2013, The Association of Coloproctology of Great Britain and Ireland (ACPGBI) issued a position statement regarding management of malignant polyps. We reviewed the management of endoscopically resected malignant colorectal polyps in a district general hospital to evaluate whether patients were being overtreated as per these guidelines.

METHODS

All patients who underwent a complete, non-piecemeal endoscopic removal of a malignant polyp between October 2013 and September 2018 were studied. Polyps were risk stratified for residual disease and followed up as per the ACPGBI. Patients were divided into two groups based on management after polypectomy. Primary outcome measured was the presence of residual tumour or involved lymph nodes in the resection specimen. Secondary outcomes included complications and recurrence.

RESULTS

Thirty-three patients were included: 21 in the non-operative group (NOG) and 12 in the operative group (OG). The ACPGBI risk score in the NOG varied between 1 and over 4 compared with the OG who all scored over 4. Two patients in the OG (16%) demonstrated residual disease. Five patients suffered a postoperative complication. No recurrences were noted in the OG and one in the NOG.

CONCLUSION

Our findings against a backdrop of the available literature suggest that the risk of residual disease after malignant polypectomy may not be as high as stated by the ACPGBI. As a result, there is a risk of overtreating patients and exposing them to the significant complications of surgery if careful consideration is not exercised.

Emergency hip disarticulations for severe necrotising fasciitis of the lower limb: a series of rare cases from a rural district general hospital

Hip disarticulation is the removal of the entire lower limb through the hip joint by detaching the femur from the acetabulum. This major ablative procedure is rarely performed for infection but may be required in severe necrotising fasciitis. We present a single centre retrospective review of all cases of emergency hip disarticulations in patients with necrotising fasciitis between 2010 and 2020. All five patients included in the review presented with acute lower limb pain and sepsis. Three patients had comorbidities predisposing them to necrotising fasciitis. Three were deemed to be high risk and two were at intermediate risk of developing necrotising fasciitis. There were two deaths in the postoperative period. Of the three survivors, two required revision surgery for a completion hindquarter amputation and one for flap closure. All three survivors had good functional outcomes after discharge from hospital. Despite its associated morbidity, emergency amputation of the entire lower limb is a life-saving treatment in cases of rapidly progressing necrotising fasciitis and should be considered as a first-line option in managing this condition.

Dual targeting of MTOR as a novel therapeutic approach for high-risk B-cell acute lymphoblastic leukemia

Children of Hispanic/Latino ancestry have increased incidence of high-risk B-cell acute lymphoblastic leukemia (HR B-ALL) with poor prognosis. This leukemia is characterized by a single-copy deletion of the IKZF1 (IKAROS) tumor suppressor and increased activation of the PI3K/AKT/mTOR pathway. This identifies mTOR as an attractive therapeutic target in HR B-ALL. Here, we report that IKAROS represses MTOR transcription and IKAROS' ability to repress MTOR in leukemia is impaired by oncogenic CK2 kinase. Treatment with the CK2 inhibitor, CX-4945, enhances IKAROS activity as a repressor of MTOR, resulting in reduced expression of MTOR in HR B-ALL. Thus, we designed a novel therapeutic approach that implements dual targeting of mTOR: direct inhibition of the mTOR protein (with rapamycin), in combination with IKAROS-mediated transcriptional repression of the MTOR gene (using the CK2 inhibitor, CX-4945). Combination treatment with rapamycin and CX-4945 shows synergistic therapeutic effects in vitro and in patient-derived xenografts from Hispanic/Latino children with HR B-ALL. These data suggest that such therapy has the potential to reduce the health disparity in HR B-ALL among Hispanic/Latino children. The dual targeting of oncogene transcription, combined with inhibition of the corresponding oncoprotein provides a paradigm for a novel precision medicine approach for treating hematological malignancies.

Neck failure following pathologically node-negative neck dissection (pN0) in oral squamous cell carcinoma: a systematic review and meta-analysis

Due to the risk of occult cervical metastasis, elective neck dissection (END) is recommended in the management of patients with early oral cavity squamous cell carcinoma (OSCC) and a clinically node-negative (cN0) neck. This paper presents a systematic review and meta-analysis of studies that recorded isolated regional recurrence (RR) in the pathologically node-negative neck dissection (pN0) neck following END in order to quantify the failure rate. Pubmed and Ovid databases were systematically searched for relevant articles published between January 2009 and January 2019. Studies reporting RR following END in patients with OSCC who had no pathological evidence of lymph node metastasis were eligible for inclusion in this meta-analysis. In addition, a selection of large head and neck units were invited to submit unpublished data. Search criteria produced a list of 5448 papers, of which 18 studies met the inclusion criteria. Three institutions contributed unpublished data. This included a total of 4824 patients with median follow-up of 34 months (2.8 years). Eight datasets included patients staged T1-T4 with RR 17.3% (469/2711), 13 datasets included patients staged T1-T2 with RR 7.5% (158/2113). Overall across all 21 studies, isolated neck recurrence was identified in 627 cases giving a RR of 13.0% (627/4824) on meta-analysis. Understanding the therapeutic effectiveness of END provides context for evaluation of clinical management of the cN0 in these patients. A pathologically negative neck does not guarantee against future recurrence.

Volume and location of the defect as predictors of speech outcome after glossectomy: correlation with a classification

The evaluation of speech outcomes after resection and reconstruction of the oral tongue remains largely unsystematic. A cross-sectional study was performed to analyse the speech outcomes of patients who underwent curative treatment with appropriate reconstruction. Sixty-nine patients were assessed for speech intelligibility and phonetics using a validated speech intelligibility assessment tool in the local language. Volume defects were classified as class I (less than one third), II (one third to half), III (half to two-thirds), or IV (two-thirds to total glossectomy). Defect location was defined as lateral, tip, or sulcus. The χ² test and Kruskal-Wallis test were used to test volume and location as predictors. Twenty-six patients had class I defects, 29 had class II defects, seven had class III defects, and seven had class IV defects. Twenty-two patients (31.9%) received adjuvant radiotherapy. Mean vowel, consonant, word, and paragraph intelligibility were 99.27%, 86.86%, 85.52%, and 88.72%, respectively. The incremental volume of the glossectomy defect was significantly correlated with speech intelligibility scores and phonatory alterations. In classes II and III, tip resection significantly affected interdental sounds. All patients in class III had affected alveolar and alveo-palatal sounds. The results positively corroborated the volume and location of the glossectomy defect to a classification system.

Mechanistic Basis for In Vivo Therapeutic Efficacy of CK2 Inhibitor CX-4945 in Acute Myeloid Leukemia

Simple Summary

Acute Myeloid Leukemia is an aggressive disease with poor outcomes. New targeted therapies that can boost the effects of currently used chemotherapy medications without added toxicity are needed. Targeting an overactive kinase, called the protein Kinase CK2 in AML, helps leukemia cells undergo cell death and helps certain chemotherapy drugs work better. Here, we present evidence that CX-4945, a CK2 inhibitor drug, effectively kills leukemia cells in mouse models and shows the mechanism of action responsible for these effects. Leukemia cells are more sensitive to a decrease in CK2 kinase levels than normal cells. Our results show that inhibiting CK2 kinase makes AML cells more susceptible to anthracycline-induced cell death. Anthracyclines like daunorubicin and doxorubicin are widely used to treat leukemia in children and adults. A rational combination of protein kinase CK2 inhibitors with the standard of care chemotherapy may help treat AML more effectively.

Abstract

Protein Kinase CK2 (Casein Kinase 2 or CK2) is a constitutively active serine-threonine kinase overactive in human malignancies. Increased expression and activity of CK2 in Acute Myeloid Leukemia (AML) is associated with a poor outcome. CK2 promotes AML cell survival by impinging on multiple oncogenic signaling pathways. The selective small-molecule CK2 inhibitor CX-4945 has shown in vitro cytotoxicity in AML. Here, we report that CX-4945 has a strong in vivo therapeutic effect in preclinical models of AML. The analysis of genome-wide DNA-binding and gene expression in CX-4945 treated AML cells shows that one mechanism, by which CK2 inhibition exerts a therapeutic effect in AML, involves the revival of IKAROS tumor suppressor function. CK2 phosphorylates IKAROS and disrupts IKAROS’ transcriptional activity by impairing DNA-binding and association with chromatin modifiers. Here, we demonstrate that CK2 inhibition decreases IKAROS phosphorylation and restores IKAROS binding to DNA. Further functional experiments show that IKAROS negatively regulates the transcription of anti-apoptotic genes, including BCL-XL (B cell Lymphoma like–2 like 1, BCL2L1). CX-4945 restitutes the IKAROS-mediated repression of BCL-XL in vivo and sensitizes AML cells to apoptosis. Using CX-4945, alongside the cytotoxic chemotherapeutic drug daunorubicin, augments BCL-XL suppression and AML cell apoptosis. Overall, these results establish the in vivo therapeutic efficacy of CX-4945 in AML preclinical models and determine the role of CK2 and IKAROS in regulating apoptosis in AML. Furthermore, our study provides functional and mechanistic bases for the addition of CK2 inhibitors to AML therapy.

Association between school racial/ethnic composition during adolescence and adult health

OBJECTIVES

School racial/ethnic segregation in U.S. schoolsDifferences in school racial/ethnic composition may increase health disparities by concentrating educational opportunities that confer long-term health benefits in schools serving predominantly wwhite students. For racial minority students, high concentrations of white students may increase exposure to racismis also associated with psychologicstress, which may ultimately reduceing the long-term health benefits from educational opportunities. Meanwhile associations of racial/ethnic academic tacking within schools and health have been mixed. We sought to test whether: 1) differences in racial/ethnic composition between schools and, 2) racial/ethnic distribution of students in academic tracks within schools are associated with long-term health benefits or risks for white, Black and Latinx students.

METHODS

We analyzed the National Longitudinal Study of Adolescent to Adult Health (12,438 participants, collected 1994-2008), to test whether the school-level segregation (percent of non-Latinx white students at participants' school during adolescence) was associated with adult health outcomes at ages 18-26 & 24-32, controlling for contextual factorscomparing Black, Latinx, and white students, and controlling for contextualf factors. A secondary analysis explored whether racial/ethnic cohorting across levels of English courses was associated with each health outcome.

RESULTS

Attending a school with a higher percent of white students was associated with higher adult depression scores, substance abuse, and worse self-rated health for black Black students; lower depression scores, better self-rated health, and alcohol abuse for white students; and no health differences for Latinx students. Greater within school racial/ethnic cohorting across English courses was associated with increased odds of alcohol abuse for white students; decreased odds of alcohol abuse for Black and Latinx students; and decreased odds of drug abuse for Black students.

CONCLUSION

Among Bblack youth, attending a school with a higher percentage of white students is associated with worse behavioral health in adulthood. Understanding the potential impacts of school racial/ethnic composition on health is critical to designing policies that maximize access to opportunity and health.Education policies should comprehensively address school quality and racism to maximize adult health.

Pirfenidone Alleviates Features of Well-Established Chronic Pancreatitis in Mouse Models

Introduction/Objective

Chronic pancreatitis (CP) is a fibro-inflammatory disease of pancreas with no targeted therapy and is considered irreversible. Antifibrotic agent pirfenidone is FDA approved for idiopathic pulmonary fibrosis.

However, exact molecular mechanism of its action is not clear. The aim of this study was to evaluate pirfenidone as a therapeutic agent for CP.

Methods

Caerulein-CP was induced in C57BL/6 mice by caerulein injections (50ug/kgx7, i.p., hourly x twice weekly x10 weeks). At 11 weeks, animals were randomized and assigned to either saline or pirfenidone group (400 mg/kg/d by oral gavage for 5 weeks). Mice were euthanized at 17 weeks. L-arginine induced CP was induced by i.p. injections of L-arginine (4.5g/kg x2 hourly, once a week x 4) and treatment was started after 5 weeks of start. Mice were sacrificed at early time-points after starting treatment. Single-cell suspension of pancreata were used for flow- cytometry. Pancreatic atrophy, histology, fibrosis and cytokine mRNA profile were evaluated. In vitro studies were done on stellate cells.

Results

The treated caerulein-CP mice had improvement in pancreas/mouse weight ratio, (7.03±0.41 vs. 4.75±0.28; p&lt;0.0001). Histology scores and fibrosis markers were reduced. Pancreatic atrophy and histology scores showed significant improvement by day 14 of treatment in L-arginine CP. Flow cytometry showed that by day 7 of treatment there was significant reduction in macrophage infiltration (1.09 ± 0.18 % vs 3.26 ± 0.4 %; p&lt;0.001) and pro-fibrotic M2 macrophage markers [IL-4 (1.5 ± 0.1 % vs 2.8 ± 0.2%; p=0.007)], while M1 marker (MHC II) did not change. mRNA levels of pro-inflammatory and pro-fibrotic cytokines decreased, and of anti-inflammatory cytokines increased. In vitro study on stellate cells showed reduction in mRNA levels of pro-fibrotic and pro-inflammatory cytokines as well as fibrosis markers in treatment group.

Conclusion

Pirfenidone ameliorates well-established CP in mouse models by altering immune cells.

Unusual presentation of intussusception: Gallstone ileus

Gallstone ileus is a rare pathology, occurring in an estimated 0.5% of cases, which preferentially affect females and the elderly population. This rare pathology is the result of a fistulous connection between the bowel and gallbladder. This connection allows gallstones to pass into the bowel leading to mechanical obstruction. On rare occasions the enteric gallstone can act as a lead point causing intussusception. We present a rare case of intussusception secondary to gallstone ileus in a young, relatively asymptomatic patient. CT played a critical role in diagnosis and appropriate management of our patient.

Abstract 2927: Targeted combination treatment for B-cell acute lymphoblastic leukemia

The CCND3 gene encodes Cyclin D3–a protein that is essential for G1/S cell cycle progression and proliferation of malignant cells. Targeting Cyclin D3 is used to treat B-cell acute lymphoblastic leukemia (B-ALL); however, the mechanisms that regulate expression of the CCND3 gene in B-ALL are largely unknown. Here, we present evidence that oncogenic Casein Kinase II (CK2) regulates expression of CCND3 and G1/S cell cycle progression via direct phosphorylation of Ikaros, a transcription regulator and tumor suppressor protein. Global genome-wide DNA-binding analysis using ChIP-seq, show that Ikaros binds the promoter of CCND3 in primary human B-ALL. The role of Ikaros in regulating CCND3 expression in B-ALL was tested using gain-of-function and loss-of-function experiments. Ikaros knock-down with shRNA results in increased transcription of CCND3 in B-ALL. Overexpression of Ikaros in human B-ALL was associated with reduced expression of CCND3. Since Ikaros activity in leukemia is regulated by pro-oncogenic Casein Kinase II (CK2), we tested whether CK2 regulates expression of CCND3 in B-ALL. Increased expression of CK2 in B-ALL results in increased expression of the CCND3 gene. This was associated with a loss of Ikaros binding to the promoter of the CCND3 gene. Inhibition of CK2 with shRNA, and/or a specific CK2 inhibitor, CX-4945, resulted in increased Ikaros binding to the CCND3 promoter and reduced expression of Cyclin D3 in B-ALL. Treatment with CX-4945 showed strong therapeutic activity in preclinical models of B-ALL. A combination treatment with CX-4945 and dexamethasone that targets G1/S cell cycle progression shows a strong synergistic effect on B-ALL cells. In conclusion, presented data show that CK2 and Ikaros regulate G1/S cell cycle progression via transcriptional regulation of the CCND3 gene in B-ALL and that CK2 inhibition represses CCND3 expression by enhancing Ikaros tumor suppressor function. Results demonstrate the synergistic efficacy of a combination treatment with CK2 inhibitor and dexamethasone and provide a rationale for the use of this combination treatment as a novel therapeutic approach for B-cell acute lymphoblastic leukemia.

Citation Format: Shriya Kane, Yali Ding, Chandrika Gowda, Jonathon Lee Payne, Soumya Iyer, Pavan K. Dhanyamraju, Chunhua Song, Dhimant Desai, Arati Sharma, Kimberly J. Payne, Sinisa Dovat. Targeted combination treatment for B-cell acute lymphoblastic leukemia [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2927.

PRL3 enhances T-cell acute lymphoblastic leukemia growth through suppressing T-cell signaling pathways and apoptosis

T cell acute lymphoblastic leukemia (T-ALL) is an aggressive malignancy of thymocytes and is largely driven by the NOTCH/MYC pathway. Yet, additional oncogenic drivers are required for transformation. Here, we identify protein tyrosine phosphatase type 4 A3 (PRL3) as a collaborating oncogenic driver in T-ALL. PRL3 is expressed in a large fraction of primary human T-ALLs and is commonly co-amplified with MYC. PRL3 also synergized with MYC to initiate early-onset ALL in transgenic zebrafish and was required for human T-ALL growth and maintenance. Mass spectrometry phosphoproteomic analysis and mechanistic studies uncovered that PRL3 suppresses downstream T cell phosphorylation signaling pathways, including those modulated by VAV1, and subsequently suppresses apoptosis in leukemia cells. Taken together, our studies have identified new roles for PRL3 as a collaborating oncogenic driver in human T-ALL and suggest that therapeutic targeting of the PRL3 phosphatase will likely be a useful treatment strategy for T-ALL.

The role of exosomes in metastasis and progression of melanoma

The mechanisms of melanoma metastasis have been the subject of extensive research for decades. Improved diagnostic and therapeutic strategies are of increasing importance for the treatment of melanoma due to its high burden of mortality in the advanced stages of the disease. Intercellular communication is a critical event for the progression of cancer. Collective evidence suggests that exosomes, small extracellular membrane vesicles released by the cells, are important facilitators of intercellular communication between the cells and the surrounding environment. Although the emerging field of exosomes is rapidly gaining traction in the scientific community, there is limited knowledge regarding the role of exosomes in melanoma. This review discusses the multifaceted role of melanoma-derived exosomes in promoting the process of metastasis by modulating the invasive and angiogenic capacity of malignant cells. The future implications of exosome research and the therapeutic potential of exosomes are also discussed.