[Efficacy and prognostic analysis of 98 cases of relapsed/refractory diffuse large B-cell lymphoma treated with second-line regimens]

Objective: To evaluate the efficacy and prognostic factors of second-line regimens for patients with relapsed/refractory diffuse large B-cell lymphoma (DLBCL). Methods: A retrospective analysis was performed in 98 patients with relapsed/refractory DLBCL who were treated with salvage regimens in Rui Jin Hospital from July 2004 to June 2016. Overall response rate (ORR) was evaluated after all treatment finished. Overall survival (OS) was analyzed by Kaplan-Meier method and multivariate by Cox proportional hazards models. Results: There were 60 males and 38 females with a median age of 55.5 (15-77) years. 48 (49.0%) patients responded to chemotherapy, and 32 (32.7%) patients achieved complete remission (CR). Factors affecting ORR were progression disease or refractory/relapse status less than 12 months after diagnosis (χ(2)=5.878, P=0.015) , IPI intermediate-high/high risk (χ(2)=5.930, P=0.015) and NCCN-IPI intermediate-high/high risk (χ(2)=4.961, P=0.026). No significance difference was observed in ORR between germinal-center B-cell type (GCB) and non-GCB (χ(2)=0.660, P=0.417). One-year and 2-year OS rates were 51.0% and 31.5%, with median OS at 13.17 months, respectively. Multivariate analysis indicated NCCN-IPI intermediate-high/high risk[HR=2.176 (95%CI 1.338-3.538) , P=0.002] and response to chemotherapy [HR=0.273 (95%CI 0.165-0.452) , P<0.001] were independent prognostic factors for survival. Conclusion: NCCN-IPI is a valid predictor of outcome for patients with relapse/refractory DLBCL. Response to chemotherapy is an independent prognostic factor for better survival.

Abstract S4-03: Targeted and selective degradation of estrogen receptor (ER) alpha by PROTACs

ERα-positive breast cancers comprise approximately 80% of all newly diagnosed cases. Current treatment approaches targeting ER signaling include antagonizing and/or downregulating ER or reducing estrogen levels. Faslodex (fulvestrant) is the only clinically-approved agent that is both a potent ER antagonist and downregulator but has limitations given its pharmacokinetics and route of administration. Over the past several years, targeted ER therapies have focused on developing selective estrogen receptor downregulators (SERDs, i.e, GDC-0810, GDC-0927, AZD9496, RAD1901). The mechanisms involved in ER downregulation by SERD binding are not completely understood, but evidence suggests that conformational changes in the receptor upon ligand binding combined with specific co-regulator interactions destabilize the receptor making it a target for passive proteasomal degradation. We hypothesized that the complex ER pharmacology required for SERD-based passive degradation might be different across various ER-positive cell lines and that targeted degradation of the receptor by actively recruiting the ubiquitin-proteasome machinery would provide a better approach for reducing ER levels. To test this hypothesis, we developed potent molecules directed against ER using our pioneering technology—proteolysis targeting chimeras (PROTACs). PROTACs are heterobifunctional molecules that actively recruit specific E3 ligases resulting in ubiquitylation and degradation of target proteins. When testing for ER degradation using several SERDs and ER PROTACs, we discovered that both fulvestrant and ER PROTACs provided robust degradation in all ER-positive lines (&lt;1 nM 50% degradation; &gt;90% reduction) whereas other SERDs did not degrade or only modestly degraded the receptor. Importantly, MCF-7 cells were uniquely sensitive to SERD-based degradation of ER compared to other cell lines. Subcutaneous administration of fulvestrant (1mpk) or ER PROTACs (10 mpk) reduced uterine ER alpha levels in immature rats (&gt;65% reduction). PROTAC-mediated degradation of ER was also achieved in breast cancer xenografts. To further validate the PROTAC mechanism, incubation of ER-positive cells with ER PROTACs resulted in increased levels of poly-ubiquitylated ERα when compared to SERDs. Lastly, to demonstrate the specificity of PROTAC-mediated ERα degradation, we utilized a cellular expression proteomics-based approach to examine over 7,000 proteins. In this experiment, only ERα and several known proteins whose genes are regulated by ERα, were significantly reduced by PROTACs. It remains to be seen how the current class of investigational downregulators will perform in the clinic. More importantly, a better understanding of the therapeutic potential and benefit of degrading the receptor instead of inhibiting the receptor needs to be explored. To that end, we continue to develop and characterize novel ER PROTACs with the anticipation that targeted ERα degradation will provide a greater clinical benefit than receptor antagonism.

Citation Format: Flanagan JJ, Rossi AK, Anderoli M, Willard RR, Gordon D, Harling J, Churcher I, Smith I, Zinn N, Bantscheff M, Crews CM, Crew A, Coleman KG, Winkler JD, Qian Y. Targeted and selective degradation of estrogen receptor (ER) alpha by PROTACs [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 S4-03.

[Clinical value of a rapid respiratory syncytial virus antigen detection in point-of-care testing]

Objective: To evaluate the clinical value of a rapid respiratory syncytial virus (RSV) antigen detection in point-of-care testing (POCT). Method: A total of 209 specimens, including 78 throat swabs (TS) and 131 nasopharyngeal aspirates (NPAs), were collected from inpatients who visited the Children's Hospital Affiliated to the Capital Institute of Pediatrics and were diagnosed as acute respiratory infection from 5 January to 7 February, 2015. These specimens were tested for RSV by a rapid antigen detection kit which was compared with reverse transcription polymerase chain reaction (RT-PCR) and direct immunofluorescence assay (DFA) for RSV detection. Result: Compared with DFA for NPAs, the sensitivity and specificity of rapid antigen detection were 83.9% and 97.3%, respectively, with Kappa value of 0.86; Compared with RT-PCR, the sensitivity (NPAs, 74.2%; TS, 77.8%) and specificity (NPAs, 100.0%; TS, 92.0%) of rapid antigen detection were high, too, with Kappa value of 0.74 in NPAs and 0.62 in TS. However, the RSV positive rate of rapid antigen detection in TS (21.7%) from pediatric patients with acute lower respiratory tract infection was lower than that in NPAs (78.3%), as well as that of RT-PCR (7.3% in TS verse 78% in NPAs). The RSV rapid antigen detection kit can be finished in about 10 minutes. Conclusion: With characteristics of high specificity, high sensitivity, being rapid, efficient and easy to operate in comparison with DFA and RT-PCR, RSV rapid antigen detection in this study is suitable for POCT. For pediatric patients with acute respiratory tract infection, NPA was better than TS for RSV detection.

Severe ovarian hyperstimulation syndrome in a naturally conceived singleton pregnancy after ovulation induction: a case report

OBJECTIVE

To present a case of severe ovarian hyperstimulation syndrome (OHSS) in a naturally conceived singleton pregnancy after ovulation induction.

CASE

A 31-year-old woman with polycystic ovarian syndrome (PCOS) underwent ovulation induction therapy. Six days later, she was admitted to the present hospital with the symptoms of OHSS. Ultrasonography confirmed the single live intrauterine pregnancy, as well as enlarged multicystic ovaries and marked ascites that required abdominal paracentesis. The woman was treated with intravenous infusion, exogenous colloid supplementation, essentiale liver treatment, rocephin anti-infective therapy for skin lymphangitis of left lower limb, and drainage of the ascites. She recovered by day 45 of admission.

CONCLUSION

Severe OHSS may develop in women with PCOS who undergo ovulation induction therapy. Serious complications may develop rapidly and therefore OHSS must be treated urgently and with multidisciplinary management.

Implication of Differential Peroxiredoxin 4 Expression with Age in Ovaries of Mouse and Human for Ovarian Aging

Ovarian aging has been associated with increased levels of reactive oxygen species and the deficiencies of antioxidant defense. The antioxidant peroxiredoxin 4 (Prdx4), as a member of Prdx protein family, controls cellular oxidative stress by reducing H2O2 levels. In previous studies, we provided evidence that Prdx4 was abundantly expressed in mouse and human ovaries and expression of Prdx4 in matured follicles was higher than that in immatured follicles. Accordingly, we speculated that Prdx4 expression could be associated with follicle development and it may be as a part of the antioxidative mechanism in follicular development. In this study, we demonstrated that Prdx4 was mainly expressed in the granulosa cells of mouse ovaries and the expression levels significantly increased along development of follicles. However, the expression levels of Prdx4 decreased when mice reached the aged stage (18 months old). Likewise a similar pattern that was observed in the mice study was also found in human ovaries where Prdx4 was expressed lower in premenopausal women than young women. Subsequent in vitro experiments indicated that Prdx4 mRNA and protein levels both increased with H2O2 in a concentrationdependent manner, but decreased rapidly with high concentration of H2O2, and the changes were closely related to cell proliferation. Taken together, these findings argue our understanding on the role of oxidative stress and antioxidant in follicular development and ovarian aging.

Abstract 1612: Overexpression or inducible expression of Snail, Zeb1 or TGFβ recapitulates epithelial-mesenchymal transition (EMT) in colorectal cancer cell lines in vitro

Epithelial-mesenchymal transition (EMT) is one of the hallmarks of cancer and a critical process providing tumor cells with the ability to metastasize to distant sites. Several previous studies have revealed that EMT plays a crucial role in the progression and aggressiveness of colorectal cancer (CRC). Snail, Zeb1 and TGFβ are considered as master EMT genes and their overexpression has been linked to metastatic disease. Our study was conducted to establish an EMT platform in-house to determine the role of Snail, Zeb1 and TGF-β1 in mediating EMT in CRC cell lines in vitro and using them for studying drug sensitivity and target validation. Screening of six CRC cell lines for expression of epithelial (E) and mesenchymal (M) markers by western blot analysis suggested that DLD-1 and HT-29 cells are epithelial in nature and were used to generate stable overexpression and tet-inducible models. Overexpression of Snail or Zeb1 or TGF-β1 induced EMT in both DLD-1 and HT-29 colorectal cancer cells as indicated by downregulation of E-cadherin and upregulation of vimentin by western blot analysis and immunofluorescence staining. These cells which have undergone EMT also showed significant growth advantage in 3D growth on matrigel or soft agar. Stable ‘E’ and ‘M’ cells were also used to test the sensitivity of various inhibitors including erlotinib, salinomycin and chemotherapeutic agents such as paclitaxel, gemcitabine, cisplatin, oxaloplatin and 5-FU. Consistent with previous findings, erlotinib showed sensitivity only in ‘E’ cells and not ‘M’ cells. Chemotherapy agents have also shown higher sensitivity in ‘E’ cells than ‘M’ cells. In contrast, Salinomycin showed equipotent sensitivity in ‘E’ and ‘M’ cells. We have also generated tet-inducible models of Snail, Zeb1 and TGF-β1 and they behaved very similar to overexpression models. These inducible models were useful to determine whether any inhibitor treatment or knock down of specific gene (target) can block EMT. In our studies, testing of a Focal Adhesion Kinase (FAK) inhibitor or Dasatinib (SFK inhibitor) as examples showed blockade of EMT in these models. Overall, establishing several EMT models in-house enabled us to validate new targets involved in EMT, test new inhibitors whether it can block EMT or study drug sensitivity in ‘E’ vs. ‘M’ cells.

Citation Format: Shripad V. Bhagwat, Nicole E. Hamm, Yu-Chih Hsu, Yuewei Qian, Robert Wild, Jonathan A. Lee, Sheng-Bin Peng. Overexpression or inducible expression of Snail, Zeb1 or TGFβ recapitulates epithelial-mesenchymal transition (EMT) in colorectal cancer cell lines in vitro. [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 1612.

Ras-association domain family 10 acts as a novel tumor suppressor through modulating MMP2 in hepatocarcinoma

Ras-Association Domain Family 10 (RASSF10) is the last identified member of the RASSF family. The functional characteristics of this new gene in human cancers remain largely unclear. Here, we examined RASSF10 for the biological functions and related molecular mechanisms in hepatocellular carcinoma (HCC). We found that RASSF10 is expressed in normal human liver tissue, but is silenced or down-regulated in 62.5% (5/8) of HCC cell lines. The mean expression level of RASSF10 was significantly lower in primary HCCs compared with their adjacent normal tissues (P<0.005, n=52). The promoter methylation contributes to the inactivation of RASSF10 as demonstrated by bisulfite genomic sequencing and demethylation treatment analyses. Transgenic expression of RASSF10 in silenced HCC cell lines suppressed cell viability, colony formation and inhibited tumor growth in nude mice (QGY7703, P<0.01; HepG2, P<0.05). Furthermore, RASSF10 was shown to induce the cell accumulation in G1 phase with the increase of p27, as well as the decrease of cyclinD1 and CDK2/CDK4. Over-expression of RASSF10 also inhibited HCC cells migration (P<0.01) or invasion (P<0.05). Adhesion genes array revealed that Matrix Metalloproteinase 2 (MMP2) was a downstream effector of RASSF10. RASSF10 acting as a tumor suppressor to inhibit HCC invasion partially mediated by Focal Adhesion Kinase or p38 MAPK to decrease the accumulation of MMP2. Our study suggests that RASSF10 acts as a tumor suppressor for HCC.

Pharmacological Modulation of GluK1 and GluK2 by NETO1, NETO2, and PSD95

The association between the kainate receptors (KARs) GluK1 and GluK2 and the modifying proteins neuropilin- and tolloid-like 1 (NETO1), neuropilin- and tolloid-like 2 (NETO2), and postsynaptic density protein 95 (PSD95) is likely to produce distinct GluK1 and GluK2 pharmacology in postsynaptic neurons. However, little is known about their corresponding modulatory effects on GluK1 and GluK2 activity in high-throughput assays for cell-based drug discovery. Using heterologous cells that potentially mimic the response in native cells in a fluorescence imaging plate reader (FLIPR) assay, we have investigated assays that incorporate (1) coexpression of GluK1 or GluK2 with their modulatory proteins (NETO1, NETO2, PSD95) and/or (2) enablement of assays with physiological concentration of native GluK1 and GluK2 agonist (glutamate) in the absence of an artificial potentiator (e.g., concanavalin A [Con A]). We found that in the absence of Con A, both NETO1 and NETO2 accessory proteins are able to potentiate kainate- and glutamate-evoked GluK1-mediated Ca(2+) influx. We also noted the striking ability of PSD95 to enhance glutamate-stimulated potentiation effects of NETO2 on GluK1 without the need for Con A and with a robust signal that could be utilized for high-throughput FLIPR assays. These experiments demonstrate the utility of heterologous cells coexpressing PSD95/NETO2 with GluK1 or GluK2 in native cell-mimicking heterologous cell systems for high-throughput assays and represent new avenues into the discovery of KAR modulating therapies.

[Gas chromatography for measurement of chlorpyrifos in serum]

OBJECTIVE

To investigate the method for the measurement of chlorpyrifos in serum by gas chromatography, and to provide a basis for emergency treatment of poisoning in clinical practice.

METHODS

Venous blood (3.0 ml) was collected from patients. After coagulation, the blood samples were centrifuged at 4 000 r/min for 5 minutes, and 0.5 ml of serum was placed in a glass test tube with a cork; 4.0 ml of ethyl acetate was then added and mixed rapidly, and this solution was subjected to extraction for 5 minutes and centrifuged at 4 000 r/min for 10 minutes. The ethyl acetate layer was placed in a conical tube and extracted twice with the same method. The extract was mixed and blow-dried with nitrogen, and the residue was dissolved with 50.0 μl ethanol. Gas chromatography was used for measurement, with a sample size of 1 μl and a retention time of 9.609 minutes.

RESULTS

The linear range of this method was 0.2~20.0 μg/ml, and the regression equation was y=2 372.6x+357.2(r=0.999 6). The detection limit of chlorpyrifos in serum was 0.05 μg/ml, and the recovery rate was 84.6%~102.4%. The relative standard deviation was 3.6%~4.8%, and the intra-day and inter-day relative standard deviations were 3.62%~5.10% and 3.77%~4.98%, respectively.

CONCLUSION

This detection method is accurate, simple, and convenient, and can be used for the clinical diagnosis of chlorpyrifos poisoning.

Abstract P6-11-01: Cost-effectiveness of pertuzumab in HER2+ metastatic breast cancer

Purpose

The Clinical Evaluation of Pertuzumab and Trastuzumab (CLEOPATRA) study showed a 15.7-month survival benefit with the addition of pertuzumab (P) to docetaxel and trastuzumab (TH) as first-line treatment for patients with HER2 overexpressing metastatic breast cancer. We performed a cost-effectiveness analysis to assess the value of the addition of pertuzumab to docetaxel and trastuzumab.

Patient and Methods

We developed a decision-analytic Markov model to evaluate the cost-effectiveness of TH with or without P in U.S. patients with metastatic breast cancer. The model followed patients weekly over their remaining lifetimes. Health states included: stable disease, progressing disease, hospice, and death. Transition probabilities were based on the CLEOPATRA study. Costs reflected the 2014 Medicare rates. Health state utilities were the same as those used in other recent cost-effectiveness studies of trastuzumab and pertuzumab. Outcomes included health benefits expressed as discounted quality-adjusted life-years (QALYs), costs in U.S. dollars, and cost-effectiveness expressed as an incremental cost-effectiveness ratio. One-way and multi-way deterministic and probabilistic sensitivity analyses explored the effects of specific assumptions.

Results

Modeled median survival was 39.4 months (TH) and 56.9 months (THP). The addition of pertuzumab resulted in an additional 1.81 life years gained (0.62 QALYs) at a cost of $472,668 per QALY gained. Deterministic sensitivity analysis showed that THP is unlikely to be cost-effective even under the most favorable assumptions, and probabilistic sensitivity analysis predicted 0% chance of cost-effectiveness at a willingness-to-pay of $100,000 per QALY gained.

Conclusion

The addition of pertuzumab to docetaxel and trastuzumab in patients with metastatic HER2+ breast cancer is unlikely to be cost-effective in the United States.

Citation Format: Qian Y, Durkee BY, Pollom EL, King M, Dudley SA, Shaffer JB, Chang DT, Gibbs IC, Goldhaber-Fiebert JD, Horst KC. Cost-effectiveness of pertuzumab in HER2+ metastatic breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P6-11-01.

Physician preferences for bone metastasis drug therapy in Canada

BACKGROUND

Currently in Canada, several bone-targeted agents (btas) with varying characteristics are available for the prevention of skeletal-related events (sres) in patients with bone metastasis secondary to solid tumours. In the present study, we evaluated the preferences of physicians in Canada for the various attributes of the available btas.

METHODS

Physicians treating patients with bone metastasis from solid tumours were invited to complete an online discrete-choice experiment. Respondents were asked to choose between pairs of hypothetical medications for virtual patients. Each hypothetical medication was described based on predefined key attributes: time until first sre, time until worsening of pain, medication-related annual risk of osteonecrosis of the jaw (onj), medication-related annual risk of renal impairment, and mode of administration. A random-parameters logit model was used to analyze the choices between hypothetical medications and thus infer physician preferences for medication attributes.

RESULTS

Responses from the 200 physicians who completed the discrete-choice experiment suggested that months until first sre, risk of renal impairment, and months until worsening of pain were considered the most important attributes affecting choice of bta. The annual risk of onj was considered the least important attribute.

CONCLUSIONS

When making treatment decisions about the choice of bta for patients with bone metastasis from solid tumours, delaying sres and worsening of pain, and reducing the risk of renal impairment are primary considerations for physicians in Canada.

Infusion of dendritic cells carrying donor lymphocytes treated with 8-methoxypsoralen and ultraviolet A light induces CD19+ IL-10+ regulatory B cells and promotes skin allograft survival

PUVA-SP DCs are immature dendritic cells (imDCs) that have taken up donor splenic lymphocytes treated with 8-methoxypsoralen and ultraviolet A light (PUVA-SPs). Phagocytosis of donor PUVA-SPs does not stimulate phenotype maturation of recipient imDCs, and infusion of PUVA-SP DCs can induce CD4(+)CD25(high)Foxp3(+) regulatory T cells (Treg). However, the regulatory effect of PUVA-SP DCs on B cells is poorly understood. In this study, we compared PUVA-SP DCs with imDCs in terms of lipopolysaccharide (LPS) responsiveness and flow cytometric analysis of interleukin (IL) 10 expression in splenic CD19(+)B cells. Our results demonstrate that PUVA-SP DCs can suppress subsequent LPS-induced DC maturation and that infusion of PUVA-SP DCs, in the absence of an immunosuppressant, significantly promotes skin allograft survival. This effect was associated with up-regulation of circulating regulatory B cells exhibiting preferential IL-10 secretion. Our results suggest that effective treatments involving infusion of PUVA-SP DCs is likely related to the modulation not only of T-cell and Treg functions but also of B-cell and regulatory B-cell (Breg) functions.