Tumor Growth Rate Research Articles

PAIP1 is a novel oncogene in human hepatocellular carcinoma

BackgroundPoly(A)-binding protein interacting protein 1 (PAIP1) is a translational initiation regulatory factor that has been reported as oncogene in multiple malignant diseases. However, its role in hepatocellular carcinoma (HCC) and the potential mechanisms have not been explored.MethodsPAIP1 expression level in HCC cell lines were detected by real-time quantitative PCR and western blotting. The proliferation and colony formation of HCC cell lines were detected by MTT and colony formation assay. The apoptosis and cell cycle were detected by flow cytometry. The volume and growth rate of the xenograft tumors were observed. The potential mechanism of PAIP1 was analyzed by miRNA Microarray Analysis and TargetScan analysis.ResultsPAIP1 is significantly upregulated in HCC cell lines. PAIP1 knockdown dramatically inhibits cell proliferation and colony formation, induces apoptosis and alters the cell cycle distribution by increasing the G2/M cell percentage. Moreover, PAIP1 knockdown significantly reduces tumorigenesis in a murine transplantation model. Bioinformatics and immunoblotting analysis reveal that PAIP1 knockdown dysregulates cyclin D pathway-related proteins.ConclusionPAIP1 plays an oncogenic role in hepatocellular carcinoma.

Natural small molecule self-assembled hydrogel inhibited tumor growth and lung metastasis of 4T1 breast cancer by regulating the CXCL1/2-S100A8/9 axis

It is crucial to inhibit tumor growth and distant metastasis for breast cancer (BC) therapy. However, the treatment primarily dependent on surgery, chemotherapy, and radiotherapy is far from satisfactory. It had been demonstrated that the CXCL1/2-S100A8/9 axis played an essential role in BC therapy. Therefore, we constructed a natural product hydrogel for BC therapy by blocking CXCL1 signaling. The GK-GA (phytochemicals of Genkwa Flos-glycyrrhizic acid) hydrogel was designed in a one-step “green” approach. The pharmacodynamics study showed GK-GA exhibited significant anti-tumor and anti-lung metastasis activities, resulting in the inhibition rate of tumor growth (IRG) over 90 % at 6.25 mg·kg−1, and did not display any obvious toxicity. In addition, the potent antitumor efficiency was also attributed to aggregation/assembly-induced retention (AIR) property. RNA sequencing analysis revealed the gene expression was significantly down-regulated in the GK-GA group, which were BCL2, CASP3, CXCL1, CXCL2, CXCR2, S100A8, S100A9, and confirmed further by western blot (WB). Our findings indicated natural product GK-GA hydrogel inhibited tumor growth and lung metastasis via the BCL2-CASP3 mitochondrial apoptosis pathway as well as the CXCL1/2-S100A8/9 pathway. This study provides inspiration for the fabrication of new excipients-free nano-dispersion in a one-step, no‐carrier‐added, organic solvent-free, “green” approach, particularly for small molecular antitumor agents.

Early on-treatment tumor growth rate (EOT-TGR) determines treatment outcomes of advanced non-small-cell lung cancer patients treated with programmed cell death protein 1 axis inhibitor

Tumor growth rate (TGR), denoted as percentage change in tumor size per month, is a well-established indicator of tumor growth kinetics. The predictive value of early on-treatment TGR (EOT-TGR) for immunotherapy remains unclear. We sought to establish and validate the association of EOT-TGR with treatment outcomes in patients with advanced non-small-cell lung cancer (aNSCLC) undergoing anti-PD-1/PD-L1 (programmed cell death protein 1/programmed death-ligand 1) therapy. This bicenter retrospective cohort study included a training cohort, a contemporaneously treated internal validation cohort, and an external validation cohort. Computed tomography images were retrieved to calculate EOT-TGR, denoted as tumor burden change per month during a period between baseline and the first imaging evaluation after immunotherapy. Kaplan-Meier methodology and Cox regression analysis were conducted for survival analyses. In the pooled cohort (n= 172), 125 patients (72.7%) were males; median age at diagnosis was 58 (range 28-79) years. Based on the training cohort, we determined the optimal cut-off value for EOT-TGR as 10.4%/month. Higher EOT-TGR was significantly associated with inferior overall survival [OS; hazard ratio (HR) 2.93, 95% confidence interval (CI) 1.47-5.83; P= 0.002], worse progression-free survival (PFS; HR 2.44, 95% CI 1.46-4.08; P= 0.001), and lower objective response rate (3.3% versus 20.9%; P= 0.040) and durable clinical benefit rate (6.7% versus 41.9%; P= 0.001). Results were reproducible in the two validation cohorts for OS and PFS. Among 43 patients who had a best response of progressive disease in the training cohort, those with high EOT-TGR had worse OS (HR 2.64; P= 0.041) and were more likely to progress due to target lesions at the first tumor evaluation (85.2% versus 0.0%; P <0.001). Higher EOT-TGR was associated with inferior OS and immunotherapeutic response in patients with aNSCLC undergoing anti-PD-1/PD-L1 therapy. This easy-to-calculate radiologic biomarker may help evaluate the abilities of immunotherapy to prolong survival and assist in tailoring patients' management. ClinicalTrials.govNCT04722406; https://clinicaltrials.gov/ct2/show/NCT04722406.

Cell-intrinsic ceramides determine T cell function during melanoma progression.

Acid sphingomyelinase (Asm) and acid ceramidase (Ac) are parts of the sphingolipid metabolism. Asm hydrolyzes sphingomyelin to ceramide, which is further metabolized to sphingosine by Ac. Ceramide generates ceramide-enriched platforms that are involved in receptor clustering within cellular membranes. However, the impact of cell-intrinsic ceramide on T cell function is not well characterized. By using T cell-specific Asm- or Ac-deficient mice, with reduced or elevated ceramide levels in T cells, we identified ceramide to play a crucial role in T cell function in vitro and in vivo. T cell-specific ablation of Asm in Smpd1fl/fl/Cd4cre/+ (Asm/CD4cre) mice resulted in enhanced tumor progression associated with impaired T cell responses, whereas Asah1fl/fl/Cd4cre/+ (Ac/CD4cre) mice showed reduced tumor growth rates and elevated T cell activation compared to the respective controls upon tumor transplantation. Further in vitro analysis revealed that decreased ceramide content supports CD4+ regulatory T cell differentiation and interferes with cytotoxic activity of CD8+ T cells. In contrast, elevated ceramide concentration in CD8+ T cells from Ac/CD4cre mice was associated with enhanced cytotoxic activity. Strikingly, ceramide co-localized with the T cell receptor (TCR) and CD3 in the membrane of stimulated T cells and phosphorylation of TCR signaling molecules was elevated in Ac-deficient T cells. Hence, our results indicate that modulation of ceramide levels, by interfering with the Asm or Ac activity has an effect on T cell differentiation and function and might therefore represent a novel therapeutic strategy for the treatment of T cell-dependent diseases such as tumorigenesis.

PET/CT radiomics for prediction of hyperprogression in metastatic melanoma patients treated with immune checkpoint inhibitors.

This study evaluated pretreatment 2[18F]fluoro-2-deoxy-D-glucose (FDG)-PET/CT-based radiomic signatures for prediction of hyperprogression in metastatic melanoma patients treated with immune checkpoint inhibition (ICI). Fifty-six consecutive metastatic melanoma patients treated with ICI and available imaging were included in the study and 330 metastatic lesions were individually, fully segmented on pre-treatment CT and FDG-PET imaging. Lesion hyperprogression (HPL) was defined as lesion progression according to RECIST 1.1 and doubling of tumor growth rate. Patient hyperprogression (PD-HPD) was defined as progressive disease (PD) according to RECIST 1.1 and presence of at least one HPL. Patient survival was evaluated with Kaplan-Meier curves. Mortality risk of PD-HPD status was assessed by estimation of hazard ratio (HR). Furthermore, we assessed with Fisher test and Mann-Whitney U test if demographic or treatment parameters were different between PD-HPD and the remaining patients. Pre-treatment PET/CT-based radiomic signatures were used to build models predicting HPL at three months after start of treatment. The models were internally validated with nested cross-validation. The performance metric was the area under receiver operating characteristic curve (AUC). PD-HPD patients constituted 57.1% of all PD patients. PD-HPD was negatively related to patient overall survival with HR=8.52 (95%CI 3.47-20.94). Sixty-nine lesions (20.9%) were identified as progressing at 3 months. Twenty-nine of these lesions were classified as hyperprogressive, thereby showing a HPL rate of 8.8%. CT-based, PET-based, and PET/CT-based models predicting HPL at three months after the start of treatment achieved testing AUC of 0.703 +/- 0.054, 0.516 +/- 0.061, and 0.704 +/- 0.070, respectively. The best performing models relied mostly on CT-based histogram features. FDG-PET/CT-based radiomic signatures yield potential for pretreatment prediction of lesion hyperprogression, which may contribute to reducing the risk of delayed treatment adaptation in metastatic melanoma patients treated with ICI.

Supramolecular Loading of DNA Hydrogels with Dye-Drug Conjugates for Real-Time Photoacoustic Monitoring of Chemotherapy.

A longstanding problem with conventional cancer therapy is the nonspecific distribution of chemotherapeutics. Monitoring drug release in vivo via noninvasive bioimaging can thus have value, but it is difficult to distinguish loaded from released drug in live tissue. Here, this work describes an injectable supramolecular hydrogel that allows slow and trackable release of doxorubicin (Dox) via photoacoustic (PA) tomography. Doxis covalently linked with photoacoustic methylene blue (MB) to monitor Doxbefore, during, and after release from the hydrogel carrier. The conjugate (MB-Dox) possesses an IC50 of 161.4× 10-9 m against human ovarian carcinoma (SKOV3) cells and loads into a DNA-clad hydrogel with 91.3% loading efficiency due to MB-Dox's inherent intramolecular affinity to DNA. The hydrogel is biodegradable by nuclease digestion, which causes gradual release of MB-Dox. This release rate is tunable based on the wt% of the hydrogel. This hydrogel maintains distinct PA contrast on the order of days when injected in vivo and demonstrates activatable PA spectral shifts during hydrogel degradation. The released and loaded payload can be imaged relative to live tissue via PA and ultrasound signal being overlaid in real-time. The hydrogel slowed the rate of the murine intraperitoneal tumor growth 72.2% more than free Dox.

Reconsideration of operative indications in pancreatic neuroendocrine neoplasms

BackgroundThe incidence of pancreatic neuroendocrine neoplasm (PNEN) has been increasing. Resection is typically indicated for PNEN, regardless of its size; however, the indications for its resection are controversial. This study aimed to evaluate the treatment results of surgical resection of PNEN at our institute.MethodsIn this single-center, retrospective, case-control study, 87 patients who underwent PNEN resection and 17 patients with PNEN who did not undergo surgical resection between 1993 and 2020 were included in this study. Clinical characteristics and outcomes were reviewed and statistically compared. Survival was also estimated for the patients in each cohort.ResultsSeventeen patients who underwent resection (20%) had lymph node metastasis. Tumors measuring ≥ 2.0 cm and multiple lesions were identified as independent predictors for lymph node metastasis (odds ratio [OR] 17.3, 95% confidence interval [CI] 3.0–100.0, p = 0.001 and OR 8.7, 95% CI 1.5–52.0, p = 0.018, respectively). There was a significant difference in the survival curves depending on the presence or absence of lymph node metastasis (5-year overall survival 74.7% vs. 94.3%, p < 0.001; 5-year recurrence-free survival: 66.3% vs. 93.6%, p < 0.001). All 17 PNEN cases under observation with a median 8 mm (range 5–23) tumor size for a median of 34 (range 2.4–114) months showed slight morphological change with a median tumor growth rate of 0.15 mm (range 0–3.33) per year.ConclusionPatients with tumors measuring ≥ 2.0 cm have a high probability of lymph node metastasis or recurrence, thereby requiring resection. PNEN measuring < 1.0 cm may be acceptable for observation.

Engineering a HemoMap Nanovaccine for Inducing Immune Responses against Melanoma

Neoantigen vaccines have opened a new paradigm for cancer immunotherapy. Here, we constructed a neoantigen nanovaccine-HemoMap, with the ability to target lymph nodes and activate immune cells. We propose a HemoMap nanovaccine consisting of the mouse melanoma highly expressed antigenic peptide Tyrp1 and a magnesium nanoadjuvant-HemoM. By immunofluorescence labeling of the nanovaccine, the lymph node targeting of the vaccine was observed and verified by a mouse near-infrared imaging system. About two-fold higher effective retention of HemoMap induces the internalization of Tyrp1 in DCs than that of free Tyrp1 in draining lymph nodes (DLNs) for 48 h. A mouse melanoma subcutaneous model was established to evaluate neoantigen-specific antitumor immune responses. In comparison to the control group, the tumor growth rate was dramatically slowed down by HemoMap treatment, and the median survival time was extended by 7 days. We discovered that effective co-delivery of Tyrp1 antigen and magnesium (Mg2+) to lymph nodes (LNs) boosted cellular internalization and activated immune cells, such as CD11c+ DCs and CD8+ T lymphocytes. Spleen lymphocytes from the HemoMap group displayed much more antitumor activity than those from the other groups. Our findings highlight that HemoMap is promising to trigger T cell responses and to provide novel nanoadjuvants strategies for cancer immunotherapy.

QOL-25. IMPACTS OF IMPLEMENTING A PROSPECTIVE TREATMENT AND SURVEILLANCE PROTOCOL FOR THE MANAGEMENT OF NF2-ASSOCIATED VESTIBULAR SCHWANNOMAS ON TUMOR GROWTH, HEARING OUTCOMES, AND QUALITY OF LIFE

Abstract Neurofibromatosis type 2 (NF2) is an autosomal dominant neurocutaneous syndrome associated with the development of nervous system tumors, including vestibular schwannomas (VS), meningiomas, and ependymomas. Although considered a rare illness, it is a source of significant morbidity, mainly due to early hearing loss leading to decreased autonomy and productivity among young adults. Bevacizumab, a monoclonal antibody against VEGF, has been shown to improve audition and tumor size in observational studies on NF2-associated VS. The most common limitations in the literature include the lack of reliable control groups, the paucity of data on quality of life, and the lack of detailed audiology testing guidelines. Moreover, the cost of bevacizumab is a limiting factor in access to care. In our Canadian tertiary care center, bevacizumab has been offered to NF2 patients with VS complications without specific indications on optimal treatment initiation time or duration. We present a hybrid cohort study protocol with retrospective and prospective arms aimed at measuring the impacts of introducing a standardized treatment and surveillance protocol on tumor growth, hearing outcomes, and quality of life. Patients from the multidisciplinary neurofibromatosis clinic at the University of Montreal Health Center, Canada, will be evaluated for inclusion in the prospective arm through regular audiological evaluations and imaging. Eligible individuals will receive bevacizumab at an initial dose of 5 mg/kg every 2 weeks for a year while participating in serial audiological, radiological, and quality of life assessments. The results will be compared to those of our historical cohort. Our primary outcomes will be tumor growth rate (% per year) for vestibular schwannomas, meningiomas and ependymomas, audiological test results, and quality of life and subjective hearing estimated through standardized questionnaires (SF-36, SSQ). We hypothesize that patients enrolled in the prospective arm will show improved clinical response compared to our historical cohort.

NIMG-81. EFFECT OF RE-TREATMENT WITH TEMOZOLOMIDE IN GRADE 2/3 IDH MUTANT GLIOMAS AT FIRST PROGRESSION

Abstract BACKGROUND Patients with WHO grade 2 and 3 IDHmt gliomas commonly receive temozolomide, with or without radiation therapy, as initial therapy. At progression, temozolomide is sometimes reinstated despite a paucity of data on effectiveness. METHODS We reviewed imaging outcomes of patients with grade 2/3 IDHmt gliomas re-treated with temozolomide at first progression between 2007 and 2019. RESULTS 15 subjects included six grade 2 and five grade 3 oligodendrogliomas, one grade 2 and three grade 3 astrocytomas. Median time between completion of first temozolomide course and initiation of re-treatment was 47 months (range, 8-126 months). Best treatment response after first progression by RANO criteria was stable disease in 10 and progressive disease in 5 patients. Median progression free survival with temozolomide re-treatment was 27.4 months (95% CI: [13.8, 41.2 months] and median overall survival 47.8 months (95% CI: [31.5, 125.6 months]). In 14 patients who had pre- and post- first tumor progression rate measurements, the mean rate of tumor growth by bidimensional product was 0.29 cm2/month (95% CI: [0.17, 0.42 cm2/month], p&amp;lt; 0.001) prior to first tumor progression versus 0.47 cm2/month (95 CI: [0.08, 0.85 cm2/month], p=0.021) during re-treatment with monotherapy temozolomide (prior vs after, p=0.371). The volumetric mean rate of tumor growth was 1.12 cc/month (95% CI: [0.31, 1.93 cc/month], p=0.010) prior to first tumor progression versus 1.29 cc/month (95% CI: [0.15, 2.43 cc/month], p=0.030) during temozolomide re-treatment (prior vs. after, p=0.802). CONCLUSION Among 15 patients with progressive IDHmt glioma re-treated with temozolomide, there was no radiographic response by RANO criteria nor a decrease in tumor growth rate during the re-treatment period compared to immediate pre-re-treatment period. These findings suggest previously treated, progressive IDHmt gliomas are generally resistant to temozolomide, underscoring the need for novel therapies.

EXTH-39. BIOMARKER DRIVEN TARGETING OF RECURRENT IDH MUTANT GLIOMA WITH ABEMACICLIB

Abstract Despite initial responsiveness to standard treatments like radiation and chemotherapy, IDH mutant gliomas inevitably recur, become more clinically aggressive, and lead to untimely death. The aggressive change in clinical outcome is driven by insensitivity to conventional methods of treatment, necessitating an improved therapeutic strategy at this stage of the disease. Greater than 20% of recurrent IDH mutant gliomas exhibit homozygous loss of CDKN2A, leading to the loss of the endogenous CDK4/6 inhibitor p16 and aberrant signaling through the CDK-RB pathway. We hypothesized that CDKN2A loss leads to enhanced sensitivity to CDK4/6 inhibitors which have been approved for use in a variety of other cancer types. We examined the sensitivity of a panel of patient-derived IDH mutant gliomas with either endogenous CDKN2A loss or CRISPR-mediated gene deletion to treatment with CDK4/6 inhibitors. We observed a correlation between CDKN2A loss and enhanced cytotoxicity following abemaciclib treatment in these glioma models. We have characterized the cell cycle profile following abemaciclib treatment by flow cytometry and western blotting in both sensitive and resistant lines. Further, abemaciclib treatment resulted in significant slowing of tumor growth rate in a subcutaneous patient-derived IDH mutant glioma model. Survival studies in an intracranial model are ongoing. These preclinical results provide foundational data to support a biomarker-driven clinical trial of CDK4/6 inhibitors in patients with recurrent IDH mutant glioma.

EXTH-16. THE ORAL IRON-MIMETIC GALLIUM MALTOLATE SUPPRESSES TREATMENT-RESISTANT GLIOBLASTOMA – IN VIVO VALIDATION

Abstract BACKGROUND We previously reported on our in vitro and in vivo studies using the metallocompound gallium maltolate (GaM) to target glioblastoma (GBM). We demonstrated a profound cytotoxic effect in vitrov and in vivo. Additionally, our preliminary in vivo data suggested a substantial inhibitory effect on tumor growth, as well as a significant extension of disease-specific survival (OS). Here, we further validate the inhibitory effects of GaM in vivo. METHODS In vitro irradiated adult GBM U87-MG cells were stereotactically implanted into the right striatum of male and female athymic rats. Advanced MR imaging at 9.4T was carried out weekly starting two weeks after implantation. Daily oral GaM (50 mg/kg) or vehicle were provided on tumor confirmation. Longitudinal advanced MRI parameters were processed for enhancing tumor ROIs in OsiriX 8.5.1 (lite) with Imaging Biometrics Software (Imaging Biometrics LLC,). Statistical analyses included Kaplan-Meier survival plots, linear mixed model (LMM) comparisons, and t-statistic for slopes comparison (as indicator of tumor growth rate). RESULTS Median OS for the male pilot cohort (5 control, 5 GaM) was 28 and 51 days, respectively; 31 and 59 days for the male replication cohort (1 control, 3 GaM); 37 and 48 days for the female replication cohort (6 control, 7 GaM). GaM-treated xenograft tumors grew significantly slower than control tumors with sex and time dependent growth rates. No significant differences were seen between male and female cohorts in both control and treatment groups at all timepoints. Hence, subsequent analyses were performed on pooled data. Median OS was 30.5 days and 48 days for control and GaM groups, respectively (p &amp;lt; .001). A strong correlation between treatment and survival (Χ2 = 6.238187; p = .0125) and tumor growth suppression (LMM; p &amp;lt; .0001) was evident. CONCLUSION We have successfully validated the inhibitory effects of GaM on GBM growth in vivo.

Simvastatin Attenuated Tumor Growth in Different Pancreatic Tumor Animal Models.

Newly diagnosed pancreatic cancer increases year by year, while the prognosis of pancreatic cancer has not been very good. Statin drugs were found to have protective effects against a variety of cancers, but their association with pancreatic cancer remains to be clarified. This study used different pancreatic cancer cell lines and in different animal models to confirm the relationship between simvastatin and pancreatic cancer. Flow cytometry and luciferase-based bioluminescent images were used to investigate the cell cycle and tumor growth changes under simvastatin treatment. Simvastatin decreased the MIA PaCa-2 cells, PANC-1 cells, and BxPC-3 cell viability significantly and may arrest the cell cycle in the G0 phase. During in vivo study, subcutaneously implanted simvastatin pre-treated pancreatic cancer cells and intraperitoneally treated simvastatin continuously demonstrated a slower tumor growth rate and decreased the tumor/body weight ratio significantly. In intravenous implant models, implanted simvastatin-pre-treated BxPC-3 cells and cells treated along with simvastatin significantly decreased the tumor growth curve. Implanting the simvastatin-pre-treated pancreatic cells in the subcutaneous model showed better growth inhibition than the intravenous model. These results suggest simvastatin treatment may relate to different signaling pathways in local growth and metastasis. Pancreatic cancer cells presented different growth patterns in different animal-induced models, which could be important for clinical reference when it comes to the relationship of long-term statin use and pancreatic cancer.

CTNI-65. INTUITT-NF2, AN ADAPTIVE PLATFORM-BASKET TRIAL FOR NEUROFIBROMATOSIS 2 PATIENTS WITH PROGRESSIVE TUMORS: INTERIM RESULTS OF THE BRIGATINIB TREATMENT ARM

Abstract Neurofibromatosis type 2 (NF2) predisposes affected individuals to vestibular schwannomas (VS), non-vestibular schwannomas (NVS), meningiomas, and ependymomas. We developed an adaptive platform-basket trial to screen multiple drugs against any type of progressive NF2-related tumor. We report the interim analysis of the first treatment arm with brigatinib, an ALK inhibitor that inhibits multiple tyrosine kinases. We conducted a multicenter, phase II, open-label study for subjects ≥12 years old with NF2 and progressive target tumors (baskets: VS, NVS, meningioma, or ependymoma). Up to 5 non-target tumors were followed in each participant. In stage 1, 20 participants (minimum of 2 participants per basket) were treated with brigatinib 180 mg daily. Tumor response was evaluated by MRI every 3 months in year 1 and every 6 months thereafter. Radiographic response (RR) was defined as ≥20% decrease in target tumor volume from baseline. The primary outcome was RR rate. Per protocol, the brigatinib arm would be discontinued if no target tumor achieved a RR at interim analysis. Twenty subjects (median age=25 years, 7 pediatric, 12 females) were treated. Target tumors included 10 VS, 3 NVS, 5 meningiomas, and 2 ependymomas; non-target tumors included 18 VS, 36 NVS, and 14 meningiomas. RR rate for target and non-target tumors was 5% and 22%, respectively. By tumor basket, RR was 28% for meningioma, 26% for non-VS, 4% for VS, and 0% for ependymomas. Annualized tumor growth rates decreased for VS, NVS, and meningioma during treatment. Brigatinib was well tolerated with one dose reduction and one discontinuation due to grade 2 diarrhea. Brigatinib treatment was associated with RR in meningiomas, VS, and NVS. In stage 2, the study will enroll 20 participants in the two most promising baskets (meningioma and NVS). This novel design provides unique ability to assess treatments for hereditary syndromes with multiple primary tumors.

Tumor Growth Rate Informs Treatment Efficacy in Metastatic Pancreatic Adenocarcinoma: Application of a Growth and Regression Model to Pivotal Trial and Real-World Data.

Methods for screening agents earlier in development and strategies for conducting smaller randomized controlled trials (RCTs) are needed. We retrospectively applied a tumor growth model to estimate the rates of growth of pancreatic cancer using radiographic tumor measurements or serum CA 19-9 values from 3033 patients with stages III-IV PDAC who were enrolled in 8 clinical trials or were included in 2 large real-world data sets. g correlated inversely with OS and was consistently lower in the experimental arms than in the control arms of RCTs. At the individual patient level, g was significantly faster for lesions metastatic to the liver relative to those localized to the pancreas. Regardless of regimen, g increased toward the end of therapy, often by over 3-fold. Growth rates of PDAC can be determined using radiographic tumor measurement and CA 19-9 values. g is inversely associated with OS and can differentiate therapies within the same trial and across trials. g can also be used to characterize changes in the behavior of an individual's PDAC, such as differences in the growth rate of lesions based on metastatic site, and the emergence of chemoresistance. We provide examples of how g can be used to benchmark phase II and III clinical data to a virtual reference arm to inform go/no go decisions and consider novel trial designs to optimize and accelerate drug development.

Immunomodulatory Properties of Mouse Mesenchymal Stromal/Stem Cells Upon Ectopic Expression of Immunoregulator Nanos2.

Mesenchymal stromal/stem cells (MSCs) are known for their involvement in modulating the immune system of mammals. This potency could be enhanced by different strategies, including regulation of key proteins, in order to meet desirable therapeutic properties. Nanos2, encoding an RNA-binding protein involved in regulation of key spermatogonial signaling pathways, has been demonstrated to downregulate a range of immune related genes in mouse embryonic fibroblasts (MEFs). Accordingly, it was hypothesized that Nanos2 functions as a potent immunosuppressing factor. This study was aimed to measure the expression profile of the immune-related genes in mouse mesenchymal stromal/stem cells (mMSCs) and assess their functional properties after Nanos2 ectopic expression. As inflammatory mediators, interferon (IFN-γ) and poly(I:C) were used to provoke an immune response. The interactions between the control and engineered mMSCs overexpressing Nanos2, with mouse peripheral blood mononuclear cells (mPBMCs) were then compared. The sensitivity of these cells to an inflammatory environment was assessed by using a conditioned medium containing high levels of inflammatory cytokines. Finally, the functional properties of the cells were investigated both in vivo and in vitro in presence of tumor and immune cells. Deep transcriptome analysis indicated that numerous genes were downregulated as a result of higher Nanos2 expression. Most of the genes subjected to gene expression alteration, were responsible for controlling responses to external stimuli, cell-cell adhesion, and wound healing. In comparison to the control cells, Nanos2-overexpressing cells showed lower expression of several immune-related genes after pretreatment with IFN-γ and poly(I:C). They also exhibited inhibitory effects against mPBMCs proliferation. Tumor growth rate, in B16-F0 administered mice was obviously increased upon their treatment with the Nanos2-mMSCs, while no tumor or very small ones were developed in the control group. In addition, the cytotoxic environment had no significant effects on Nanos2-mMSCs. According to the literature, MSCs are believed to be tuned very precisely by their internal and external conditions to act as either pro-inflammatory or anti-inflammatory agents. We show here that Nanos2 plays a significant role in promoting anti-inflammatory properties when expressed at higher levels by MSCs. This approach could be adopted for controlling the excessive inflammatory conditions in clinical programs, however more experiments are required to confirm it. In Brief Viral transduction was used to over express Nanos2 in mouse mesenchymal stromal/stem cells (mMSCs). Induced expression of Nanos2 downregulated the expression of immune-related genes and proteins. These modified mMSCs switched to an immunosuppressive state, even in the presence of pro-inflammatory cytokines; and could also contribute to tumor progression in a mouse model.

Cabozantinib sensitizes microsatellite stable colorectal cancer to immune checkpoint blockade by immune modulation in human immune system mouse models.

Immune checkpoint inhibitors have been found to be effective in metastatic MSI-high colorectal cancers (CRC), however, have no efficacy in microsatellite stable (MSS) cancers, which comprise the majority of mCRC cases. Cabozantinib is a small molecule multi-tyrosine kinase inhibitor that is FDA approved in advanced renal cell, medullary thyroid, and hepatocellular carcinoma. Using Human Immune System (HIS) mice, we tested the ability of cabozantinib to prime MSS-CRC tumors to enhance the potency of immune checkpoint inhibitor nivolumab. In four independent experiments, we implanted distinct MSS-CRC patient-derived xenografts (PDXs) into the flanks of humanized BALB/c-Rag2nullIl2rγnullSirpαNOD (BRGS) mice that had been engrafted with human hematopoietic stem cells at birth. For each PDX, HIS-mice cohorts were treated with vehicle, nivolumab, cabozantinib, or the combination. In three out of the four models, the combination had a lower tumor growth rate compared to vehicle or nivolumab-treated groups. Furthermore, interrogation of the HIS in immune organs and tumors by flow cytometry revealed increased Granzyme B+, TNFα+ and IFNγ+ CD4+ T cells among the human tumor infiltrating leukocytes (TIL) that correlated with reduced tumor growth in the combination-treated HIS-mice. Notably, slower growth correlated with increased expression of the CD4+ T cell ligand, HLA-DR, on the tumor cells themselves. Finally, the cabozantinib/nivolumab combination was tested in comparison to cobimetinib/atezolizumab. Although both combinations showed tumor growth inhibition, cabozantinib/nivolumab had enhanced cytotoxic IFNγ and TNFα+ T cells. This pre-clinical in vivo data warrants testing the combination in clinical trials for patients with MSS-CRC.

Ultrasound-Mediated Antitumor Therapy via Targeted Acoustic Release Carrier of Carbon Monoxide (TARC-CO).

As one of the most valuable endogenous gas signaling molecules, carbon monoxide (CO) has been demonstrated in numerous studies to show excellent promise in the treatment of diseases, such as cancer. However, for many years, the inherent high affinity of CO for hemoglobin severely impeded the clinical transformation of CO-based treatments. Therefore, the controlled delivery of CO to target tissues has become a common challenge. Herein, an efficient ultrasonic-triggered and targeted CO release strategy was constructed based on a novel targeted acoustic release carrier of carbon monoxide (TARC-CO) that we synthesized in this study. The designed TARC-COs could afford a safe, stable, and ultrasound-guided delivery of CO in vivo by loading a specified dose of CO inside microbubbles, resulting in breast tumor suppression. Taking advantage of the high loading capacity of microbubbles, the unit volume of TARC-CO suspension could encapsulate up to 337.1 ± 8.0 (×103 ppm) of CO. In addition, the satisfactory ultrasound contrast-enhanced ability of TARC-COs achieved real-time interactive guidance and visual policing of CO delivery. For the in vitro antitumor study, TARC-COs with ultrasonic irradiation were demonstrated to effectively induce mitochondrial dysfunction by reducing mitochondrial membrane potential, leading to the apoptosis of 4T1 cells. In addition, we realized that TARC-CO-based treatment could significantly slow the growth rate of tumors by inducing apoptosis, inhibiting the proliferation of cancer cells, and limiting tumor angiogenesis. In summary, this proof-of-concept study demonstrates the feasibility and tremendous potential of TARC-COs for controlled release of CO, which can be expected to provide new inspirations and a promising perspective for therapy based on active gases.

AS1411aptamer conjugated liposomes for targeted delivery of arsenic trioxide in mouse xenograft model of melanoma cancer

Development and characterizing of AS1411aptamer conjugated liposomes for targeted delivery of arsenic trioxide is the primary goal of this study to increase the drug safety and efficacy in the treatment of solid tumors. The targeted liposomes were constructed by the thin film method, and arsenic trioxide was loaded as cobalt (II) hydrogen arsenite (CHA). The liposomal structure was examined by Fourier Transform Infra-red Spectroscopy and field emission scanning electron microscopy. In addition, particle sizes and zeta potential of the CHA-loaded liposomes (CHAL) and aptamer-functionalized CHA-loaded liposomes (AP-CHAL) were determined. An atomic absorption spectrometer was used to quantify the encapsulation efficiency and in vitro drug release. In vitro cytotoxicity of CHAL and AP-CHAL were evaluated using MTT assay in Murine melanoma (B16) and Mouse Embryonic Fibroblast cell lines. The encapsulation efficiency of CHAL and AP-CHAL was reported as 60.2 ± 6.5 % and 58.7 ± 4.2 %, respectively. The enhanced cellular uptake of aptamer-conjugated liposomes was displayed by Fluorescence imaging. In vivo antitumor activity of CHAL and AP-CHAL in the B16 tumor-xenograft mouse model was dramatically observed. All mice in the CHAL group survived to the end of treatment and showed body weight gain. However, the distinct antitumor effect was observed in the AP-CHAL-treated group, and the tumor protrusion completely disappeared in 50 % of the mice. The inhibition rate of tumor growth of CHAL and AP-CHAL was 92.73 % and 97.67 %, respectively. Furthermore, histopathology studies demonstrated that CHAL and AP-CHAL did not induce significant toxicity in mice tissues. AP-CHAL can be used as an effective drug delivery system with high potential in treating solid tumors.

ODP338 Neuromedin B Receptor Antagonist Suppresses ACTH Secretion and Cell Proliferation in Human and Mouse Corticotroph Adenoma

Abstract Objective We previously reported that Neuromedin B (NMB) is expressed in murine pituitary corticotrophs under adrenal insufficiency (1). Because NMB is also expressed in several cancer cells and stimulates ACTH secretion, we hypothesized that NMB is related to corticotroph adenoma cell proliferation and hormone secretion. To examine this hypothesis, we investigated the effects of a NMB receptor (NMBR) antagonist on AtT-20 cells, a tumor xenograft model and patient-derived corticotroph adenoma cells. Methods 1. NMB and NMBR expression in human pituitary adenoma: We performed real-time qPCR and immunostaining on human pathological specimens of corticotroph and non-functioning pituitary adenomas to investigate NMB and NMBR expression. 2. Experiments in AtT-20 cells: We extracted RNAs, proteins and mediums from AtT-20 cells after incubation with NMBR antagonist PD168368, and performed real-time qPCR, western blotting and ELISA analyses. We also performed WST-1 assay to investigate cell proliferation. 3. Experiments in a tumor xenograft model: AtT-20 cells in Matrigel were injected subcutaneously into BALB/c-nu mice. A week after inoculation, we administered 1.2 mg/kg PD168368 intraperitoneally once daily for 14 days. Upon completion of treatment, tumors were measured and cardiac blood was collected. 4. Experiments in patient-derived corticotroph adenoma cells: We isolated surgically resected human corticotroph adenoma cells from patients who underwent trans-sphenoidal surgery and investigated mRNA expression and medium ACTH secretion after incubation with PD168368. Statistical analysis: Comparisons between two groups were made by unpaired Student t test. Multiple groups were compared using one-way ANOVA followed by Dunnett's test for comparison with control group. Statistical significance was defined as p &amp;lt; 0. 05. Results 1. NMB and NMBR expression levels were significantly higher in human corticotroph adenomas (13 and 33 times higher, respectively) than in non-functioning adenomas in the qPCR analyses. Immunostaining confirmed higher expression of NMB and NMBR in corticotroph adenoma. 2. Treatment with 100 nM PD168368 significantly suppressed Pomc mRNA and protein expression in AtT-20 cells by 22% and 25% respectively compared control group. Medium ACTH secretion, mRNA and protein expression of cyclin E1 and cell proliferation were also suppressed by PD168368. 3. Mice treated with PD168368 had significantly lower tumor growth rate, plasma ACTH and corticosterone than control group (70 vs 161%, 97 vs 180 pg/ml, 813 vs 1045 ng/ml, respectively). 4. Treatment with PD168368 significantly suppressed POMC mRNA expression (12-31%) in 4 out of 6 patient-derived corticotroph adenoma cells. Medium ACTH secretion was also suppressed (14-53%) in 3 out of 4 cases which could be evaluated. Cyclin E mRNA expression were also suppressed in 3 out of 4 cases in which POMC mRNA expression were suppressed. Conclusions NMBR antagonist may represent a potential treatment for Cushing disease, which effect may be mediated by decreased cyclin E expression. Reference: (1) Kameda H et al., Endocrinology 2014;155(7): 2492–9. Presentation: No date and time listed