Jianmin Pan

Plasma miR-21: a potential diagnostic marker of colorectal cancer.

Objectives:The main objective of this study was to investigate the potential use of circulating microRNAs (miRNAs) as biomarkers of sporadic colorectal cancer (CRC). Background:CRC, a leading cause of death, is curable if detected early. There is an unmet need for an accurate, noninvasive biomarker of CRC. MiRNAs are non–protein-coding RNAs regulating gene expression that play a role in CRC development. Methods:Levels of 380 miRNAs were determined using microfluidic array technology (Applied Biosystems) in a “training” set of 30 CRC patients from whom cancer and adjacent normal tissue were collected. The 4 most dysregulated miRNAs (P < 0.05, false discovery rate (FDR): 10%) were then validated in a second blinded “test” set of 16 CRC patients from whom cancer and normal adjacent tissue had been collected. Validated tissue miRNAs were then evaluated in a plasma “test” set consisting of 30 CRC patients and 30 individuals without CRC. The most dysregulated tissue miRNAs were then validated in an independent new plasma test set consisting of 20 CRC patients with 20 age-, -, and race-matched subjects without CRC. Results:Nineteen of 380 miRNAs were dysregulated in CRC tissue in the tissue “training” set (P < 0.05, FDR: 10%). The 2 most upregulated (miR-31; miR-135b) and most downregulated (miR-1; miR-133a) miRNAs identified CRC in our “test” set with 100% sensitivity and 80% specificity. MiR-31 was more upregulated in stages III and IV compared with stages I and II (P < 0.05). In the “plasma” group, miR-21 differentiated CRC patients from controls with 90% specificity and sensitivity. Conclusions:Plasma miRNAs provide reliable and noninvasive markers for CRC. Plasma miR-21 warrants study in larger cohorts. It seems uniquely promising as a plasma biomarker for CRC.

A plasma microRNA panel for detection of colorectal adenomas: a step toward more precise screening for colorectal cancer.

Objective:The main objective of this study was to investigate the potential use of circulating microRNAs (miRNAs) as biomarkers of colorectal (CR) adenomas. Background:Detection of precancerous lesions such as CR adenoma is a key to reduce CR cancer (CRC) mortality. There is a great need for accurate, noninvasive biomarkers for detection of CR adenoma and CRC. MiRNAs are non-protein-coding RNAs that regulate gene expression. Our prior work investigated the dysregulation of 5 plasma miRNAs in CRC patients. As intended, we undertook a more comprehensive plasma-miRNA screening study in patients with CR adenoma and CRC. Methods:We screened for 380 plasma-miRNAs using microfluidic array technology (Applied BioSystems) in a screening cohort of 12 healthy controls, 9 patients with CR adenomas, and 20 patients with CRC. A panel of the most dysregulated miRNAs (P < 0.05, False Discovery Rate: 5%) was then validated in a blinded cohort of 26 healthy controls, 16 patients with large adenomas, and 45 patients with CRC. Results:A panel of 8 plasma miRNAs (miR-532-3p, miR-331, miR-195, miR-17, miR-142-3p, miR-15b, miR-532, and miR-652) distinguished polyps from controls with high accuracy [area under curve (AUC) = 0.868 (95% confidence interval [CI]: 0.76–0.98)]. In addition, a panel of 3 plasma miRNAs (miR-431, miR-15b, and miR-139-3p) distinguished Stage IV CRC from controls with an [AUC = 0.896 (95% CI: 0.78–1.0)]. Receiver-operating-characteristic curves of miRNA panels for all CRC versus controls and polyps versus all CRC showed AUC values of 0.829 (95% CI: 0.73–0.93) and 0.856 (95% CI: 0.75–0.97), respectively. Conclusions:Plasma miRNAs are reliable, noninvasive, and inexpensive markers for CR adenomas. This miRNA panel warrants study in larger cohorts. Plasma-based assays could provide better screening compliance compared to fecal occult blood or endoscopic screening.

Increasing use of elective mastectomy and contralateral prophylactic surgery among breast conservation candidates: a 14-year report from a comprehensive cancer center.

Background: First-line surgical options for early-stage breast cancer include breast-conserving surgery (BCS) or mastectomy. We analyzed factors that influence the receipt of mastectomy and resultant trends over time. Methods: We analyzed the rates of mastectomy and BCS for 1634 women who underwent upfront surgical treatment for AJCC stage 0, I, or II breast cancer between 1995 and 2008 using data from the University of Louisville James Graham Brown Cancer Center Tumor Registry. We examined the trend of treatment over time and assessed the probability of receiving mastectomy using multivariate logistic regression. Results: Overall, 65.9% of women received BCS, and 34.1% received mastectomy over a 14-year period (annual BCS rate range, 38.6% to 77.7%). The mastectomy rate substantially decreased from 43.5% in 1995 to 22.5% in 2004 (P=0.0007) but then increased to 51.7% in 2008 (P<0.0001). During the years between 2004 and 2008 (vs. 1995 to 2003), there was a significant increase in the rates of mastectomy performed in conjunction with immediate reconstruction (IR: 35.7% vs. 8.4%; P<0.0001) and/or contralateral prophylactic mastectomy (CPM: 22.9% vs. 3.3%; P<0.0001). On the basis of the multivariate analysis, the rate of receiving mastectomy was drastically higher for patients treated since 2004 (vs. before 2004), uninsured and government-insured (vs. privately insured) patients, patients with pT2 disease (vs. pTis or pT1), patients with pN1 disease (vs. pNX or pN0). Conclusions: In this longitudinal registry study, major independent determinants of mastectomy for early-stage breast cancer include year of diagnosis, insurance status, and stage. Mastectomy rates declined until 2004, but have since increased in conjunction with immediate reconstruction and contralateral prophylactic mastectomy. Additional study is needed to identify the underlying reasons for and unintended consequences of the reemergence of radical surgery for early-stage breast cancer in the era of multidisciplinary care.

Phase II trial of the regulatory T cell-depleting agent, denileukin diftitox, in patients with unresectable stage IV melanoma

BackgroundWe previously found that administration of an interleukin 2/diphtheria toxin conjugate (DAB/IL2; Denileukin Diftitox; ONTAK) to stage IV melanoma patients depleted CD4+CD25HIFoxp3+ regulatory T cells and expanded melanoma-specific CD8+ T cells. The goal of this study was to assess the clinical efficacy of DAB/IL2 in an expanded cohort of stage IV melanoma patients.MethodsIn a single-center, phase II trial, DAB/IL2 (12 μg/kg; 4 daily doses; 21 day cycles) was administered to 60 unresectable stage IV melanoma patients and response rates were assessed using a combination of 2-[18 F]-fluoro-2-deoxy-glucose (FDG)-positron emission tomography (PET) and computed tomography (CT) imaging.ResultsAfter DAB/IL2 administration, 16.7% of the 60 patients had partial responses, 5% stable disease and 15% mixed responses. Importantly, 45.5% of the chemo/immuno-naïve sub-population (11/60 patients) experienced partial responses. One year survival was markedly higher in partial responders (80 ± 11.9%) relative to patients with progressive disease (23.7 ± 6.5%; p value < 0.001) and 40 ± 6.2% of the total DAB/IL2-treated population were alive at 1 year.ConclusionsThese data support the development of multi-center, randomized trials of DAB/IL2 as a monotherapy and in combination with other immunotherapeutic agents for the treatment of stage IV melanoma.Trial registrationNCT00299689

Melanoma cell-derived exosomes promote epithelial-mesenchymal transition in primary melanocytes through paracrine/autocrine signaling in the tumor microenvironment.

The tumor microenvironment is abundant with exosomes that are secreted by the cancer cells themselves. Exosomes are nanosized, organelle-like membranous structures that are increasingly being recognized as major contributors in the progression of malignant neoplasms. A critical element in melanoma progression is its propensity to metastasize, but little is known about how melanoma cell-derived exosomes modulate the microenvironment to optimize conditions for tumor progression and metastasis. Here, we provide evidence that melanoma cell-derived exosomes promote phenotype switching in primary melanocytes through paracrine/autocrine signaling. We found that the mitogen-activated protein kinase (MAPK) signaling pathway was activated during the exosome-mediated epithelial-to-mesenchymal transition (EMT)-resembling process, which promotes metastasis. Let-7i, an miRNA modulator of EMT, was also involved in this process. We further defined two other miRNA modulators of EMT (miR-191 and let-7a) in serum exosomes for differentiating stage I melanoma patients from non-melanoma subjects. These results provide the first strong molecular evidence that melanoma cell-derived exosomes promote the EMT-resembling process in the tumor microenvironment. Thus, novel strategies targeting EMT and modulating the tumor microenvironment may emerge as important approaches for the treatment of metastatic melanoma.

Pulmonary Dysfunction in Survivors of Childhood Hematologic Malignancies after Allogeneic Hematopoietic Stem Cell Transplantation

The number of long‐term survivors of allogeneic hematopoietic stem cell transplantation (allo‐HSCT) is increasing; however, few studies have addressed their long‐term pulmonary function.

Actinomycin D synergistically enhances the efficacy of the BH3 mimetic ABT-737 by downregulating Mcl-1 expression

Many types of cancer cells possess the ability to evade apoptosis, leading to their rapid and uncontrolled proliferation. As major regulators of apoptosis, Bcl-2 proteins serve as emerging targets for novel chemotherapeutic strategies. In this study, we examined the involvement of Bcl-2 proteins in apoptosis induced by the chemotherapeutic agent actinomycin D. A dramatic decrease in anti-apoptotic myeloid leukemia cell differentiation protein (Mcl-1) mRNA and protein expression was detected upon actinomycin D treatment. Further, Mcl-l over-expression caused resistance to cell death upon treatment with actinomycin D, implicating a role for the down-regulation of Mcl-1 in actinomycin D-induced apoptosis. We also explored the therapeutic potential of actinomycin D in combination with ABT-737, an experimental agent that inhibits anti-apoptotic Bcl-2 proteins. Actinomycin D sensitized cells to ABT-737 treatment in a Bak- or Bax-dependent manner. Importantly, low concentrations of actinomycin D and ABT-737 were more effective in inducing cell death in transformed cells than their untransformed counterparts. A synergistic effect of actinomycin D and ABT-737 on cell death was observed in several human tumor cell lines. Like actinomycin D treatment, knocking down Mcl-1 expression greatly sensitized tumor cells to ABT-737, and Mcl-1 over-expression abrogated the cytotoxic effect induced by ABT-737 and actinomycin D. These results suggest that the down-regulation of Mcl-1 by actinomycin D is likely responsible for the observed synergistic effect between the two drugs. Overall, our studies provide compelling evidence that the combination of actinomycin D and ABT-737 may lead to an effective cancer treatment strategy.

Locoregional recurrence in patients with triple-negative breast cancer: preliminary results of a single institution study.

Purpose: To examine the impact of radiotherapy on breast cancer patients with triple-negative (ER-, PR-, HER2/neu-) disease. Materials and Methods: A prospectively collected database of 152 triple negative breast cancer patients was initiated in 2004. A total of 77 patients who had all phases of their therapy (surgery, chemotherapy, and radiotherapy) at our institution with a minimum of 2-months follow-up are included. Patients with all types of surgery (lumpectomy or mastectomy), chemotherapy (neoadjuvant or adjuvant), and radiotherapy (tangents only or comprehensive nodal irradiation) are included. Patients received radiotherapy in the setting of breast-conservation and in the postmastectomy setting for ≥5 cm primary tumors and/or ≥4 positive lymph nodes. Patients were divided into 2 groups for statistical analysis, based on whether they received radiotherapy or not. Results: In the cohort, 53 (69%) received radiotherapy, 24 (31%) received no radiotherapy. The median follow-up was 23.2 months (range, 2.0–63.1). In the alive patients, the median follow-up time was 25.6 (range, 2.0–63.1) months. Patients who received radiotherapy were significantly more likely to be of a higher AJCC stage (P < 0.001) than patients who did not receive radiotherapy. Of the patients who received radiotherapy, 33 (61.1%) did so for breast conservation. For the entire group, 1- and 3-year overall survivals are 90.9% and 86.3%, respectively. The 3-year actuarial locoregional relapse-free survival probability for patients who received radiation was higher than those who did not receive radiation (79.6% vs. 57.9%, P = 0.049). Conclusions: Despite significantly lower AJCC stage, patients with triple-negative breast cancer who do not undergo radiotherapy have a significantly higher risk of locoregional recurrence.

Delay of adjuvant chemotherapy after elective mastectomy and immediate reconstruction in breast-conservation candidates: a matched-pair analysis.

Objectives:To analyze factors that influence the timing of adjuvant chemotherapy in patients who are candidates for breast-conservation therapy (BCT) but elect mastectomy with immediate reconstruction (M-IR). Methods:We identified 35 consecutively treated patients with stage I or II breast cancer between 2004 and 2009 who underwent M-IR and adjuvant chemotherapy from the University of Louisville Cancer Registry. We matched these patients for age and AJCC stage to 35 controls who underwent BCT and adjuvant chemotherapy. We examined the timing and delay of initiation of chemotherapy using univariate logistic regression and McNemar test for matched pairs. Results:For the 70 patients evaluated, the median age was 46 years (range, 30 to 65 y), and the distribution for stage I, IIA, and IIB was 22.9%, 65.7%, and 11.4%, respectively. The 2 groups were well balanced in terms of race, rural/urban status, smoking, diabetes, insurance coverage, and histology. For BCT and M-IR, the median time to chemotherapy initiation was 38 days (range, 25 to 103 d) and 55 days (range, 30 to 165 d), respectively. Patients undergoing M-IR were more likely to experience any delay (>45 d; 54.3% vs. 22.9%; P<0.001) and/or significant delay (>90 d; 20.0% vs. 2.9%; P<0.001). On univariate logistic regression analysis, surgery type had a major impact on delay of chemotherapy (odds ratio=8.35; 95% confidence interval, 2.86-24.4; P<0.001). Conclusions:The use of M-IR in breast-conservation candidates independently predicts for delay in initiation of adjuvant chemotherapy. Further study is needed to qualify the causes and clinical significance of these delays.

Extraintestinal Manifestations of Inflammatory Bowel Disease and the Influence of Smoking

Aims: To define the number/frequency of organ systems affected by extraintestinal manifestations (EIMs), to identify factors affecting the clinical course of inflammatory bowel disease (IBD) and EIM development, and to determine the impact of smoking, disease duration and location on the diagnosis of EIMs in Crohns disease (CD) and ulcerative colitis (UC). Methods: IBD patients were derived from a single university colorectal surgery practice. Smoking data were obtained through a modified Behavioral Risk Factor Surveillance System survey. The frequencies of arthritis/arthralgia, primary sclerosing cholangitis (PSC), ocular and cutaneous EIMs were determined. Results: Of the 757 patients evaluated (CD 488, UC 269), 50% had ≥1 EIM. Arthritis/arthralgia, cutaneous and ocular EIMs were significantly higher in frequency in CD compared to UC patients. Prolonged disease duration was associated with increased prevalence of arthritis/arthralgia in IBD (p ≤ 0.001) as well as PSC (p = 0.049), ocular (p = 0.030) and cutaneous (p = 0.009) EIMs in CD. Disease location affected the occurrence of EIMs in CD. Smoking appeared to increase the prevalence of ocular EIMs in UC (p = 0.026). Conclusion: Arthritis/arthralgia, cutaneous and ocular EIMs occurred in a significantly higher proportion of CD patients. CD patients with longer disease duration had a significantly higher prevalence of PSC, ocular and cutaneous EIMs. Smoking was found to increase ocular EIMs in UC.