Living donor liver transplantation for colorectal cancer liver metastases: Midterm outcomes at a single center in North America.

In recent years, liver transplantation has emerged as a treatment for patients with stage IV colorectal liver metastases (CRLM). Given the limited number of available deceased donor grafts, the use of living donor liver transplantation (LDLT) can be an important option. We performed a retrospective analysis of 10 patients that underwent LDLT for CRLM at our institution. A total of 90% of patients were male, with median age of 58 years and median model for end-stage liver disease score of 11 (range: 6-32). The rectum was the most common primary location (40%). Synchronous liver tumors were found in 50%. Pretransplant patients underwent resection (60%), hepatic-artery infusion pumping (50%), and/or radiofrequency ablation (50%). Everybody underwent adjuvant chemotherapy. Median cold ischemia time was 103 minutes (range: 93-207 minutes), and median total OR time was 11.5 hours (range: 8.5-13.9 hours). In total, 30% of patients had postoperative complications requiring reoperation. Mean recurrence-free survival was 2.2 years (95% confidence interval, 1.2-3.2 years), and mean overall survival was 3.0 years (95% confidence interval, 2.5-3.6 years). In total, 30% of patients suffered a recurrence, and 90% of patients are currently alive. This study represents the largest single-center analysis in North America of patients undergoing LDLT for CRLM. LDLT is a safe and effective alternative for patients with CRLM who do not have progressive disease or extrahepatic metastasis.

Interaction between cold ischemia time and Kidney Donor Profile Index on postrenal transplant outcomes.

We analyzed whether there is an interaction between the Kidney Donor Profile Index (KDPI) and cold ischemia time (CIT) in recipients of deceased donor kidney transplant (KTs). Adults who underwent KTs in the United States between 2014 and 2020 were included and divided into 3 KDPI groups (≤20%, 21%-85%, >85%) and 4 CIT strata (<12, 12-17.9, 18-23.9, ≥24 hours). Multivariate analyses were used to test the interaction between KDPI and CIT for the following outcomes: primary graft nonfunction (PGNF), delayed graft function (DGF), estimated glomerular filtration rate (eGFR) at 6 and 12 months, patient survival, graft survival, and death-censored graft survival (DCGS). A total of 69,490 recipients were analyzed: 18,241 (26.3%) received a graft with KDPI ≤20%, 46,953 (67.6%) with KDPI 21%-85%, and 4,296 (6.2%) with KDPI >85%. Increasing KDPI and CIT were associated with worse post-KT outcomes. Contrary to our hypothesis, howerver, the interaction between KDPI and CIT was statistically significant only for PGNF and DGF and eGFR at 6 months. Paradoxically, the negative coefficient of the interaction suggested that increasing duration of CIT was more detrimental for low and intermediate-KDPI organs relative to high-KDPI grafts. Conversely, for mortality, graft survival, and DCGS, we found that the interaction between CIT and KDPI was not statistically significant. We conclude that, high KDPI and prolonged CIT are independent risk factors for inferior outcomes after KT. Their interaction, however, is statistically significant only for the short-term outcomes and more pronounced on low and intermediate-KDPI grafts than high-KDPI kidneys.

Donor-recipient race-ethnicity concordance and patient survival after liver transplantation.

INTRODUCTION: We assessed the association between patient survival after liver transplantation (LT) and donor-recipient race-ethnicity (R/E) concordance. METHODS: The Scientific Registry of Transplant Recipients (SRTR) was retrospectively analyzed using data collected between 2002 and 2019. Only adults without history of prior organ transplant and recipients of LT alone were included. The primary outcome was patient survival. Donors and recipients were categorized into five R/E groups: White/Caucasian, African American/Black, Hispanic/Latino, Asian, and Others. Statistical analyses were performed using Kaplan-Meier survival curves and Cox Proportional Hazards models, adjusting for donor and recipient covariates. RESULTS: 85,427 patients were included. Among all the R/E groups, Asian patients had the highest 5-year survival (81.3%; 95% CI = 79.9-82.7), while African American/Black patients had the lowest (71.4%; 95% CI = 70.3-72.6) (P < 0.001). Lower survival rates were observed in recipients who received discordant R/E grafts irrespective of their R/E group. The fully adjusted hazard ratio for death was statistically significant in African American/Black (aHR 1.07-1.18-1.31; P < 0.01) and in White∕Caucasian patients (aHR 1.00-1.04-1.07; P = 0.03) in the presence of donor-recipient R/E discordance. CONCLUSION: Disparities in post-LT outcomes might be influenced by biological factors in addition to well-known social determinants of health.

Systematic review and meta-analysis of open versus laparoscopy-assisted versus pure laparoscopic versus robotic living donor hepatectomy.

The value of minimally invasive approaches for living donor hepatectomy remains unclear. Our aim was to compare the donor outcomes after open versus laparoscopy-assisted versus pure laparoscopic versus robotic living donor hepatectomy (OLDH vs. LALDH vs. PLLDH vs. RLDH). A systematic literature review of the MEDLINE, Cochrane Library, Embase, and Scopus databases was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) statement (up to December 8, 2021). Random-effects meta-analyses were performed separately for minor and major living donor hepatectomy. The risk of bias in nonrandomized studies was assessed using the Newcastle-Ottawa Scale. A total of 31 studies were included. There was no difference in donor outcomes after OLDH versus LALDH for major hepatectomy. However, PLLDH was associated with decreased estimated blood loss, length of stay (LOS), and overall complications versus OLDH for minor and major hepatectomy, but also with increased operative time for major hepatectomy. PLLDH was associated with decreased LOS versus LALDH for major hepatectomy. RLDH was associated with decreased LOS but with increased operative time versus OLDH for major hepatectomy. The scarcity of studies comparing RLDH versus LALDH/PLLDH did not allow us to meta-analyze donor outcomes for that comparison. There seems to be a marginal benefit in estimated blood loss and/or LOS in favor of PLLDH and RLDH. The complexity of these procedures limits them to transplant centers with high volume and experience. Future studies should investigate self-reported donor experience and the associated economic costs of these approaches.

Exercise Training Decreases Hepatic Injury and Metastases Through Changes in Immune Response to Liver Ischemia/Reperfusion in Mice.

BACKGROUND AND AIMS: Liver ischemia/reperfusion injury (IRI) induces local and systemic inflammation in which neutrophil extracellular traps (NETs) are major drivers. IRI markedly augments metastatic growth, which is consistent with the notion that the liver IRI can serve as a premetastatic niche. Exercise training (ExT) confers a sustainable protection, reducing IRI in some animal models, and has been associated with improved survival in patients with cancer; however, the impact of ExT on liver IRI or development of hepatic metastases is unknown. APPROACH AND RESULTS: Mice were randomized into exercise (ExT) and sedentary groups before liver IRI and tumor injection. Computerized dynamic network analysis of 20 inflammatory mediators was used to dissect the sequence of mediator interactions after ischemia/reperfusion (I/R) that induce injury. ExT mice showed a significant decrease in hepatic IRI and tissue necrosis. This coincided with disassembly of complex networks among inflammatory mediators seen in sedentary mice. Neutrophil infiltration and NET formation were decreased in the ExT group, which suppressed the expression of liver endothelial cell adhesion molecules. Concurrently, ExT mice revealed a distinct population of infiltrating macrophages expressing M2 phenotypic genes. In a metastatic model, fewer metastases were present 3 weeks after I/R in the ExT mice, a finding that correlated with a marked increase in tumor-suppressing T cells within the tumor microenvironment. CONCLUSIONS: ExT preconditioning mitigates the inflammatory response to liver IRI, protecting the liver from injury and metastases. In light of these findings, potential may exist for the reduction of liver premetastatic niches induced by liver IRI through the use of ExT as a nonpharmacologic therapy before curative surgical approaches.

Function and longevity of renal grafts from high-KDPI donors.

BACKGROUND: High kidney-donor profile index (KDPI) kidneys have a shorter survival than grafts with lower KDPI values. It is still unclear, however, whether their shorter longevity depends on an inferior baseline function, faster functional decline, or the combination of both. METHODS: We analyzed the estimated glomerular filtration rate (eGFR) of 605 consecutive recipients of deceased donor kidney transplants (KT) at 1, 3, 6, 12, 18, 24, 36, 48, and 60 months. Comparisons were performed among four groups based on KDPI quartile: Group I-KDPI ≤ 25% (n = 151), Group II-KDPI 26-50% (n = 182), Group III-KDPI 51-75% (n = 176), and Group IV-KDPI 〉 75% (n = 96). Linear mixed model analysis was subsequently used to assess whether KDPI was independently associated with the decline in eGFR during the first 5-years after KT. We also analyzed the incidence of delayed graft function (DGF), rejection within the first year after KT, patient survival, graft survival, and death censored graft survival based on KDPI group. FINDINGS: High-KDPI grafts had lower eGFR immediately after KT, had a higher incidence of DGF and rejection. However, there were no signifcant differences in the adjusted rate (slope) of decline in eGFR among the four KDPI groups (P = .06). Although patient survival was signigicantly lower for recipients of high-KDPI grafts, death-censored graft survival was similar among the four KDPI groups (P = .33). CONCLUSIONS: The shorter functional survival of high-KDPI grafts seems to be due to their lower baseline eGFR rather than a more rapid functional decline after KT.

Treatment modalities and long-term outcomes of hepatic hemangioendothelioma in the United States.

BACKGROUND: We analyzed the outcomes of patients with hepatic epithelioid hemangioendothelioma (HEHE) in the United States after stratification by their most definitive treatment. METHODS: The National Cancer Data Base was used to identify patients with HEHE between 2004 and 2018. Patients were divided in four treatment groups: no surgical therapy, ablation, liver resection or liver transplantation. Demographics and clinical characteristics were compared, and Kaplan Meier functions and Cox-regression were used for unadjusted and adjusted survival analyses. RESULTS: Among a total of 334 patients, 218 (65.2%) were managed non-surgically, 74 (22.1%) underwent hepatic resections, 35 (10.4%) underwent liver transplantation and 7 (2.1%) underwent ablations. The overall median survival was 111 months (95%CI 73-149) after liver transplantation, 69 months (95%CI 45-92) after hepatic resection, 38 months (95%CI 0-78) after ablation and 80 months (95%CI 70-90) for patients managed by watchful waiting (P < 0.001). After adjustment, patients who underwent liver transplantation were found to have a better survival when compared to other therapies (Hazard Ratio: 0.61, 95% Confidence Interval: 0.38-0.97, p = 0.035). CONCLUSIONS: This study reports the outcomes of the largest cohort of patients with HEHE. The longest survival was observed after liver transplantation, followed by non-surgical management and hepatic resection. Because of selection bias, future studies to better characterize what criteria should be used for the selection of treatment modalities for HEHE are urgently needed.

The closing survival gap after liver transplantation for hepatocellular carcinoma in the United States.

BACKGROUND: Socio-economic inequalities among different racial/ethnic groups have increased in many high-income countries. It is unclear, however, whether increasing socio-economic inequalities are associated with increasing differences in survival in liver transplant (LT) recipients. METHODS: Adults undergoing first time LT for hepatocellular carcinoma (HCC) between 2002 and 2017 recorded in the Scientific Registry of Transplant Recipients (SRTR) were included and grouped into three cohorts. Patient survival and graft survival stratified by race/ethnicity were compared among the cohorts using unadjusted and adjusted analyses. RESULTS: White/Caucasians comprised the largest group (n=9,006, 64.9%), followed by Hispanic/Latinos (n=2,018, 14.5%), Black/African Americans (n=1,379, 9.9%), Asians (n=1,265, 9.1%) and other ethnic/racial groups (n=188, 1.3%). Compared to Cohort I (2002-2007), the 5-year survival of Cohort III (2012-2017) increased by 18% for Black/African Americans, by 13% for Whites/Caucasians, by 10% for Hispanic/Latinos, by 9% for patients of other racial/ethnic groups and by 8% for Asians (All P values<0.05). Despite Black/African Americans experienced the highest survival improvement, their overall outcomes remained significantly lower than other ethnic∕racial groups (adjusted HR for death=1.20; 95%CI 1.05-1.36; P=0.005; adjusted HR for graft loss=1.21; 95%CI 1.08-1.37; P=0.002). CONCLUSION: The survival gap between Black/African Americans and other ethnic/racial groups undergoing LT for HCC has significantly decreased over time. However, Black/African Americans continue to have the lowest survival among all racial/ethnic groups.

Time to Surgery and Colon Cancer Survival in the United States.

PURPOSE: Time to surgery (TTS) is of concern to patients diagnosed with cancer and their physicians. Controversy surrounds the impact of TTS on colon cancer survival. There are limited national data evaluating the association; thus, our aim was to estimate the overall survival (OS) impact from increasing TTS for patients with colon cancer. METHODS: Using the National Cancer Data Base (NCDB), we assessed OS as a function of time between diagnosis and surgery by evaluating intervals encompassing <7, 7 to 30, 31 to 60, 61 to 90, 91 to 120, and 121 to 180 days in length. All patients were diagnosed with nonmetastatic colon cancer and underwent surgery as initial treatment. Our main outcome was OS as a function of time between diagnosis and surgery, after adjusting for patient, demographic, and tumor-related factors using Cox regression models and propensity score-based weighting. RESULTS: A total of 514,103 patients diagnosed between 1998 and 2012 were included. Individuals having <7, 7 to 30, 31 to 60, 61 to 90, 91 to 120, and 121 to 180 days between diagnosis and surgery comprised 35.4%, 45%, 15.1%, 2.9%, 1%, and 0.6% of the patients, respectively. There was a steady increase in median TTS across the years. On multivariable analysis, TTS >30 days or within the first week independently increased mortality risk. There was a significant increase in mortality with TTS 31 to 60 [hazard ratio (HR) 1.13], 61 to 90 (HR 1.49), <7 (HR 1.56), 91 to 120 (HR 2.28), and 121 to 180 (HR 2.46) compared to surgery performed 7 to 30 days after diagnosis (P < 0.001). CONCLUSIONS: TTS is independently associated with OS and this represents a public health issue that should be addressed at a national level. Although time is required for evaluation before surgery, efforts to reduce TTS should be pursued.

Medicaid expansion and the management of pancreatic cancer.

BACKGROUND: Medicaid expansion under the Affordable Care Act has improved access to screening and treatment for certain cancers. It is unclear how this policy has affected the diagnosis and management of pancreatic cancer. METHODS: Using a quasi-experimental difference-in-differences (DID) approach, we analyzed Medicaid and uninsured patients in the National Cancer Data Base during two time periods: pre-expansion (2011-2012) and postexpansion (2015-2016). We investigated changes in cancer staging, treatment decisions, and surgical outcomes. RESULTS: In this national cohort, pancreatic cancer patients in expansion states had increased Medicaid coverage relative to those in nonexpansion states (DID = 17.49, p < 0.01). Medicaid expansion also led to an increase in early-stage diagnoses (Stage I/II, DID = 4.71, p = 0.03), higher comorbidity scores among surgical patients (Charlson/Deyo score 0: DID = -13.69, p = 0.02), a trend toward more neoadjuvant radiation (DID = 6.15, p = 0.06), and more positive margins (DID = 11.69, p = 0.02). There were no differences in rates of surgery, postoperative outcomes, or overall survival. CONCLUSION: Medicaid expansion was associated with improved insurance coverage and earlier stage diagnoses for Medicaid and uninsured pancreatic cancer patients, but similar surgical outcomes and overall survival. These findings highlight both the benefits of Medicaid expansion and the potential limitations of policy change to improve outcomes for such an aggressive malignancy.

Portal vein thrombosis and renal dysfunction: a national comparative study of liver transplant recipients for NAFLD versus alcoholic cirrhosis.

The prevalence of portal vein thrombosis (PVT), renal dysfunction (RD), and simultaneous PVT/RD in liver transplantation (LT) is poorly understood. We analyzed the prevalence of PVT, RD, simultaneous PVT/RD, and the outcomes of adult recipients of LT for nonalcoholic fatty liver disease (NAFLD) and alcoholic liver disease (ALD) between 2006 and 2016 in the United States. We found that the prevalence of PVT (7.2% â†’ 11.3%), RD (33.8% â†’ 39.2%), and simultaneous PVT/RD (2.4% â†’ 4.5%) has increased significantly over the study period (all P-values <0.05). NAFLD patients had a higher proportion of PVT (14.8% vs. 9.2%), RD (45.0% vs. 42.1%), and simultaneous PVT/RD (6.5% vs. 3.9%; all P-values <0.05). 90-day mortality was 3.8%, 6.3%, 6.8%, and 9.8% for PVT(-)/RD(-), PVT(-)/RD(+), PVT(+)/RD(-), and PVT(+)/RD(+) recipients, respectively (P < 0.01). 5-year survival was 82.1%, 75.5%, 74.8%, and 71.1% for PVT(-)/RD(-), PVT(-)/RD(+), PVT(+)/RD(-), and PVT(+)/RD(+) recipients, respectively (P < 0.05). In conclusion, the prevalence of PVT, RD, and simultaneous PVT/RD has increased among LT recipients, especially for those with NAFLD. The short- and long-term outcomes of recipients with PVT, RD, and simultaneous PVT/RD were inferior to patients without those risk factors irrespective of their indication for LT. No differences in patient outcomes were found between ALD and NAFLD recipients after stratification by risk factors.

Neutrophil extracellular traps as a novel biomarker to predict recurrence-free and overall survival in patients with primary hepatic malignancies.

BACKGROUND: The incidence of primary hepatic malignancies including Hepatocellular carcinoma (HCC) and cholangiocarcinoma (CC) is on the rise. (i) Surgery remains the mainstay of potential curative treatment, however the vast majority of patients will recur and not be amenable to curative therapy. (ii) Inflammation has been associated with poor prognosis, however there is no preoperative marker that can predict recurrence-free- or overall survival. Our aim is to correlate inflammation measured as neutrophil extracellular traps (NETs) with survival. METHODS: A retrospective analysis was performed using sera/tissue from patients with hepatic malignancies. NET levels were measured in the serum (MPO-DNA) or tumor (Cit-H3). Log rank analysis for RFS/OS was performed. RESULTS: Cancer patients had higher pre-surgery MPO-DNA levels compared to healthy individuals (healthy vs cancer: 2.6 ± 1.0 ng/ml vs 34.7 ± 2.13 ng/ml; p < 0.0001). High pre-surgery serum NET levels were associated with shorter RFS/OS compared to those with low levels (RFS-HCC: HR: 2.91, 95% CI: 1.61-5.26, p < 0.0001, RFS-CC: HR: 3.22, 95% CI: 1.33-7.77 p < 0.0093). High Cit-H3 tumor levels similarly predicted shorter RFS/OS. CONCLUSION: The current study shows a correlation between pre-operative NET levels and survival. Studying NET formation as a biomarker pre-surgery can help identify patients that could benefit from closer follow-up due to higher risk for recurrence.

The liver transplant risk score prognosticates the outcomes of liver transplant recipients at listing.

BACKGROUND: We assessed if the risk of post-liver transplant mortality within 24 h could be stratified at the time of listing using the liver transplant risk score (LTRS). Secondary aims were to assess if the LTRS could stratify the risk of 30-day, 1-year mortality, and survival beyond the first year. METHODS: MELD, BMI, age, diabetes, and the need for dialysis were the five variables used to calculate the LTRS during patients' evaluation for liver transplantation. Mortality rates at 24 h, 30 days, and 1-year were compared among groups of patients with different LTRS. Patients with ABO-incompatibility, redo, multivisceral, partial graft and malignancies except for hepatocellular carcinoma were excluded. Data of 48,616 adult liver transplant recipients were extracted from the Scientific Registry of Transplant Recipients between 2002 and 2017. RESULTS: 24-h mortality was 0.9%, 1.0%, 1.1%, 1.7%, 2.3%, 2.0% and 3.5% for patients with LTRS of 0,1,2,3,4, 5 and ≥ 6, respectively (P < 0.001). 30-day mortality was 3.5%, 4.2%, 4.9%, 6.2%, 7.6%, 7.2% and 10.1% respectively (P < 0.001). 1-year mortality was 8.6%, 10.8%, 12.9%, 13.9%, 18.5%, 20.3% and 28.6% respectively (P < 0.001). 10-year survival was 61%, 56%, 57%, 54%, 47%, and 31% for patients with 0, 1, 2, 3, 4, 5 and ≥ 6 points respectively (P < 0.001). CONCLUSION: Perioperative mortality and long-term survival of patients undergoing LT can be accurately estimated at the time of listing by the LTRS.

MicroRNA-301a (miR-301a) is induced in hepatocellular carcinoma (HCC) and down- regulates the expression of interferon regulatory factor-1.

Hepatocellular carcinoma (HCC) tumors evade death in part by downregulating expression of the tumor suppressor gene Interferon regulatory factor-1 (IRF-1). However, the molecular mechanisms accounting for IRF-1 suppression in HCC have not been well described. In this study, we identified a novel microRNA-301a (miR-301a) binding site in the 3'-untranslated region (3'- UTR) of the human IRF-1 gene and hypothesized a functional role for miR-301a in regulating HCC growth. We show that miR-301a is markedly upregulated in primary HCC tumors and HCC cell lines, while IRF-1 is down-regulated in a post-transcriptional manner. MiR-301a regulates basal and inducible IRF-1 expression in HCC cells with an inverse relationship between miR-301a and IRF-1 expression in HCC cells. Chronic hypoxia induces miR-301a in HCC in vitro and decreases IRF-1 expression. Finally, miR-301a inhibition increases apoptosis and decreases HCC cell proliferation. These findings suggest that targeting of IRF-1 by miR-301a contributes to the molecular basis for IRF-1 downregulation in HCC and provides new insight into the regulation of HCC by miRNAs.

Race and Health Disparities in Patient Refusal of Surgery for Early-Stage Pancreatic Cancer: An NCDB Cohort Study.

AIM: To identify factors associated with refusal of surgery in patients with early-stage pancreatic cancer and estimate the impact of this decision on survival. METHODS: Using the National Cancer Data Base, 26,358 patients were identified with potentially resectable tumors (pretreatment clinical stage I: T1 or T2 N0M0). Multivariate models were employed to identify factors predicting failure to undergo surgery and assess the impact on survival. RESULTS: Of early-stage patients who were recommended surgery, 7.8% (N = 992) refused surgery for resectable early-stage pancreatic cancer. On multivariable analysis, patients were more likely to refuse surgery if they were older [odds ratio (OR) = 1.18; 95% confidence interval (CI) 1.16-1.19], female (OR = 1.52; 95% CI 1.33-1.73), African American (vs White, OR = 1.79; 95% CI 1.37-2.34), on Medicare/Medicaid (vs private, OR = 2.75; 95% CI 1.54-4.92) or had higher Charlson-Deyo score (2 vs 0, OR = 1.33; 95% CI 1.03-1.72). Patients were also significantly more likely to refuse surgery if they were seen at a center that is not an academic/research program (OR 1.9; 95% CI 1.6-2.27). Patients who were recommended surgery but refused had significantly worse survival than those with stage I who received surgery [median survival 6.8 vs 24 months, Cox hazard ratio (HR) 3.41; 95% CI 3.12-3.60]. CONCLUSIONS: The percentage of patients refusing surgery for operable early-stage pancreatic cancer has been decreasing in the last decade but remains a significant issue that affects survival. Disparities in refusal of surgery are independently associated with several variables including gender, race, and insurance. To mitigate national disparities in surgical care, future studies should focus on exploring potential reasons for refusal and developing communication interventions.

Radioembolization for Hepatocellular Carcinoma: A Nationwide 10-Year Experience.

PURPOSE: To examine the US nationwide experience with transarterial radioembolization (TARE) for hepatocellular carcinoma (HCC) in the years 2003-2012 and the prognostic factors associated with overall survival. MATERIALS AND METHODS: A retrospective cohort study from the National Cancer Database included 110,139 adult patients with HCC between 2003 and 2012, of whom 1,222 received TARE. Primary outcome of interest was mortality after treatment. Univariate and multivariate analyses for factors predicting mortality were performed for 961 patients treated between 2003 and 2011. Overall survival was estimated by Kaplan-Meier method. RESULTS: There was a steady increase in utilization of TARE in the past decade. Most patients were white men with median age of 64 years. Of those patients, 67% received treatment at an academic institution, 42% were American Joint Committee on Cancer stage I or II, and 10% had metastatic disease at the time of treatment. Median overall survival was 13.3 months. Overall survival varied by patient and tumor characteristics. Female patients with tumors < 5 cm or stage I or II disease benefited the most from treatment. Outcomes were the same across all age groups. Patients who were African American or had metastatic disease tended to have worse outcomes. CONCLUSIONS: Use of TARE in patients with HCC has been increasing. Several factors are significantly associated with a less favorable outcome after TARE, including male sex, large tumors, and extrahepatic disease. These data can be used for designing future radioembolization trials.

A Tumor Cell-Selective Inhibitor of Mitogen-Activated Protein Kinase Phosphatases Sensitizes Breast Cancer Cells to Lymphokine-Activated Killer Cell Activity.

Dual specificity mitogen-activated protein kinase (MAPK) phosphatases [dual specificity phosphatase/MAP kinase phosphatase (DUSP-MKP)] have been hypothesized to maintain cancer cell survival by buffering excessive MAPK signaling caused by upstream activating oncogenic products. A large and diverse body of literature suggests that genetic depletion of DUSP-MKPs can reduce tumorigenicity, suggesting that hyperactivating MAPK signaling by DUSP-MKP inhibitors could be a novel strategy to selectively affect the transformed phenotype. Through in vivo structure-activity relationship studies in transgenic zebrafish we recently identified a hyperactivator of fibroblast growth factor signaling [(E)-2-benzylidene-5-bromo-3-(cyclohexylamino)-2,3-dihydro-1H-inden-1-one (BCI-215)] that is devoid of developmental toxicity and restores defective MAPK activity caused by overexpression of DUSP1 and DUSP6 in mammalian cells. Here, we hypothesized that BCI-215 could selectively affect survival of transformed cells. In MDA-MB-231 human breast cancer cells, BCI-215 inhibited cell motility, caused apoptosis but not primary necrosis, and sensitized cells to lymphokine-activated killer cell activity. Mechanistically, BCI-215 induced rapid and sustained phosphorylation of extracellular signal-regulated kinase (ERK), p38, and c-Jun N-terminal kinase (JNK) in the absence of reactive oxygen species, and its toxicity was partially rescued by inhibition of p38 but not JNK or ERK. BCI-215 also hyperactivated MKK4/SEK1, suggesting activation of stress responses. Kinase phosphorylation profiling documented BCI-215 selectively activated MAPKs and their downstream substrates, but not receptor tyrosine kinases, SRC family kinases, AKT, mTOR, or DNA damage pathways. Our findings support the hypothesis that BCI-215 causes selective cancer cell cytotoxicity in part through non-redox-mediated activation of MAPK signaling, and the findings also identify an intersection with immune cell killing that is worthy of further exploration.

CD4+ T cell-derived IL-21 and deprivation of CD40 signaling favor the in vivo development of granzyme B-expressing regulatory B cells in HIV patients.

IL-21 can induce both plasma cells and regulatory B cells. In this article, we demonstrate that untreated HIV patients display CD4(+) T cells with enhanced IL-21 expression and high in vivo frequencies of regulatory B cells overexpressing the serine protease granzyme B. Granzyme B-expressing regulatory B cells (GraB cells) cells from HIV patients exhibit increased expression of CD5, CD43, CD86, and CD147 but do not produce IL-10. The main functional characteristic of their regulatory activity is direct granzyme B-dependent degradation of the TCR-ζ-chain, resulting in significantly decreased proliferative T cell responses. Although Th cells from HIV patients secrete IL-21 in a Nef-dependent manner, they barely express CD40L. When culturing such IL-21(+)CD40L(-) Th cells with B cells, the former directly induce B cell differentiation into GraB cells. In contrast, the addition of soluble CD40L multimers to T cell/B cell cultures redirects B cell differentiation toward plasma cells, indicating that CD40L determines the direction of IL-21-dependent B cell differentiation. As proof of principle, we confirmed this mechanism in a patient lacking intact CD40 signaling due to a NEMO mutation. The majority of peripheral B cells from this patient were GraB cells and strongly suppressed T cell proliferation. In conclusion, GraB cells represent potent regulatory B cells in humans that are phenotypically and functionally distinct from B10 cells and occur in early HIV infection. GraB cells may contribute significantly to immune dysfunction in HIV patients, and may also explain ineffective Ab responses after vaccination. The use of soluble CD40L multimers may help to improve vaccination responses in HIV patients.