Decrease In Tumor Volume Research Articles

Dual intron-targeted CRISPR-Cas9-mediated disruption of the AML RUNX1-RUNX1T1 fusion gene effectively inhibits proliferation and decreases tumor volume in vitro and in vivo.

Oncogenic fusion drivers are common in hematological cancers and are thus relevant targets of future CRISPR-Cas9-based treatment strategies. However, breakpoint-location variation in patients pose a challenge to traditional breakpoint-targeting CRISPR-Cas9-mediated disruption strategies. Here we present a new dual intron-targeting CRISPR-Cas9 treatment strategy, for targeting t(8;21) found in 5-10% of de novo acute myeloid leukemia (AML), which efficiently disrupts fusion genes without prior identification of breakpoint location. We show in vitro growth rate and proliferation reduction by 69 and 94% in AML t(8;21) Kasumi-1 cells, following dual intron-targeted disruption of RUNX1-RUNX1T1 compared to a non t(8;21) AML control. Furthermore, mice injected with RUNX1-RUNX1T1-disrupted Kasumi-1 cells had in vivo tumor growth reduction by 69 and 91% compared to controls. Demonstrating the feasibility of RUNX1-RUNX1T1 disruption, these findings were substantiated in isolated primary cells from a patient diagnosed with AML t(8;21). In conclusion, we demonstrate proof-of-principle of a dual intron-targeting CRISPR-Cas9 treatment strategy in AML t(8;21) without need for precise knowledge of the breakpoint location.

Dendropanax morbiferus H. Lév. Leaf Extract Inhibits the Proliferation of MDA-MB-231 Breast Cancer Cells and Induces Apoptosis via the MAPK Pathway In Vitro and In Vivo.

The toxic side effects of therapies against breast cancer can affect the quality of life of patients, necessitating the use of naturally-derived therapeutics. Here, we investigated the effects of Dendropanax morbiferus H. Lév. leaf (DPL) extract on breast cancer cells in vitro and in vivo to assess its anticancer potential. MDA-MB-231 breast cancer cells were treated with DPL, and the in vitro effect of DPL on the cells was evaluated through an MTT assay, DAPI staining, annexin V/propidium iodide double staining, and western blotting. The in vivo effects of DPL were measured through the MDA-MB-231 tumor xenograft mouse model. A TUNEL assay and immunohistochemistry were used to determine the extent of apoptosis and p-p38 expression in tumor tissues, respectively. DPL treatment significantly suppressed cell viability in a concentration-dependent manner. Furthermore, DPL treatment resulted in increased apoptotic body formation, apoptosis rate, cleaved poly (ADP-ribose) polymerase and B-cell lymphoma 2 (Bcl-2)-associated X protein levels, phosphorylation of mitogen-activated protein kinase (MAPK) pathway proteins, and decreased Bcl-2 levels. In addition, the antitumor effect in vivo was confirmed through the xenograft model, where decreased tumor volume and weight following DPL administration were observed. Further, apoptosis and increased p-p38 levels in tumor tissues were observed, and no pathological abnormalities were found in the liver or kidney. DPL inhibits proliferation through MAPK-mediated apoptosis in breast cancer cells and tumors, suggesting the potential of DPL as a natural therapeutic agent for breast cancer.

Biocompatible Aza-BODIPY-Biotin Conjugates for Photodynamic Therapy of Cancer.

With an objective to develop efficient photosensitizers to cancerous tissues, we synthesized two novel biocompatible sensitizers based on aza-BODIPYs incorporated with heavy atoms and biotin moieties. The bioconjugates DPR2a and DPR2b exhibited a favorable absorption range (600-750 nm) with excellent triplet-state quantum yields (up to 79%) and singlet oxygen generation yields (up to 75%). In vitro photobiological investigations employing MDA-MB-231 breast cancer cell lines exhibited rapid cellular uptake, negligible dark toxicity, and high photocytotoxicity. The mechanism of cell death of these systems was predominantly due to the mitochondrial damage, leading to apoptosis mediated via the generation of singlet oxygen-triggered reactive oxygen species. The in vivo studies with the representative conjugate DPR2a employing female NOD/SCID mice models showed inhibition in tumor growth and significantly decreased tumor volume post photodynamic therapy (PDT) treatment. Our results validate that both DPR2a and DPR2b with iodine incorporation exhibit favorable and superior photophysical and photobiological aspects and demonstrate thereby their potential applications in imaging and PDT of cancer.

Endoscopic endonasal transsphenoidal surgery for pituitary adenomas

Endoscopic endonasal transsphenoidal surgery (EETS) is a widely accepted technique for the surgical resection of pituitary tumours. In this report, we present our single-centre experience with EETS for pituitary adenomas, mainly focusing on its efficacy and postoperative complications. Among 100 patients who underwent EETS, 57 (57%) were female and 43 were (43%) male. The mean age of the patients was 51.55 ± 13.51 years. Nonfunctional adenoma was found in 61 (61%) patients, acromegaly was found in 29 (29%) patients, Cushing’s disease in six (6%), and prolactinoma was found in four (4%) patients. On average, a 75.8% decrease in the postoperative tumour volume was observed in nonfunctional adenomas. Surgical cure was achieved in 51.7% of patients with acromegaly, 50% of those with Cushing’s disease, and 25% of those with prolactinoma. The most common postoperative complication was found to be cerebrospinal fluid fistula.

Nanoliposomal VEGF-R2 peptide vaccine acts as an effective therapeutic vaccine in a murine B16F10 model of melanoma

BackgroundThe vascular endothelial growth factor receptor-2 (VEGFR-2) plays an important role in melanoma development and progression. Peptide vaccines have shown great potential in cancer immunotherapy by targeting VEGFR-2 as a tumor-associated antigen and boosting the immune response against both tumor cells and tumor endothelial cells. Despite this, the low efficiency of peptide vaccines has resulted in moderate therapeutic results in the majority of studies. Enhancing the delivery of peptide vaccines using nanoliposomes is an important strategy for improving the efficacy of peptide vaccines. In this regard, we designed VEGFR-2-derived peptides restricted to both mouse MHC I and human HLA-A*02:01 using immunoinformatic tools and selected three peptides representing the highest binding affinities. The peptides were encapsulated in nanoliposomal formulations using the film method plus bath sonication and characterized for their colloidal properties.ResultsThe mean diameter of peptide-encapsulated liposomes was around 135 nm, zeta potential of − 17 mV, and encapsulation efficiency of approximately 70%. Then, vaccine formulations were injected subcutaneously in mice bearing B16F10-established melanoma tumors and their efficiency in triggering immunological, and anti-tumor responses was evaluated. Our results represented that one of our designed VEGFR-2 peptide nanoliposomal formulations (Lip-V1) substantially activated CD4+ (p < 0.0001) and CD8+ (P < 0.001) T cell responses and significantly boosted the production of IFN-γ (P < 0.0001) and IL-4 (P < 0.0001). Furthermore, this formulation led to a significant decrease in tumor volume (P < 0.0001) and enhanced survival (P < 0.05) in mice.ConclusionOur findings suggest that the nanoliposomal formulation containing VEGFR-2 peptides could be a promising therapeutic vaccination approach capable of eliciting strong antigen-specific immunologic and anti-tumor responses.

Effect of Target Changes on Target Coverage and Dose to the Normal Brain in Fractionated Stereotactic Radiation Therapy for Metastatic Brain Tumors

We evaluated the dosimetric effect of tumor changes in patients with fractionated brain stereotactic radiation therapy (SRT) on the tumor and normal brain using repeat verification magnetic resonance imaging (MRI) in the middle of the treatment period. Fifteen large intracranial metastatic lesions with fractionated SRT were scanned employing standardized planning MRI (MRI-1). Repeat verification MRI (MRI-2) were performed during the middle of the irradiation period. Gross tumor volume (GTV) was defined as the volume of the contrast-enhancing lesion on T1-weighted MRI with gadolinium contrast agent. The doses to the tumor and normal brain were evaluated on the MRI-1 scan. Beam configuration and intensity on the initial volumetric modulated arc therapy plan were used to evaluate the dose to the tumor and the normal brain on MRI-2. We evaluated the effect of D98% (percent dose irradiating 98% of the volume) on the GTV using the plans on the MRI-1 and MRI-2 scans. For the normal brain, the V90%, V80%, and V50% (volume of the normal brain receiving >90%, 80%, and 50% of the prescribed dose, respectively) were investigated. Three (20% of the total) and 4 (26% of the total) tumors exhibited volume shrinkage or enlargement changes of >10%. Five (33% of the total) tumors exhibited volume shrinkage and enlargement changes of <10%. Three tumors (20% of the total) showed no volume changes. D98% of the GTV increased in patients with tumor shrinkage because of dose inhomogeneity and decreased in patients with tumor enlargement, with a coefficient of determination of 0.28. The V90%, V80%, and V50% increase with decreasing tumor volumes and were linearly related to the tumor volume difference with a coefficient of determination values of 0.97, 0.98, and 0.97, respectively. Repeat verification MRI for brain fractionated SRT during the treatment period should be considered to reduce the magnitude of target underdosing or normal brain overdosing.

Abstract PR006: PMR-116, a novel inhibitor of ribosome biogenesis with antitumor activity in preclinical models of prostate cancer

Abstract Advanced prostate cancer is characterised by mutations and amplifications of genes involved in regulating protein synthesis. PTEN-loss stimulates activity of the mTOR pathway, while amplification of MYC leads to increased ribosome biogenesis and elevated mRNA translation rate. Our previous work has demonstrated the efficacy of co-targeting ribosome biogenesis, via inhibition of RNA Pol I activity, and 4E-BP1 phosphorylation to suppress prostate cancer growth in vivo in GEMM of PCa and in patient-derived xenografts(1-3). In a collaboration with Pimera Inc., we investigated the efficacy of their new lead RNA Pol I inhibitor PMR-116 in models of prostate cancer. PMR-116 is well tolerated in vivo in mice and can be given at 300mg/kg weekly. Using the Hi-MYC mouse model of PCa we show that dosing 6-month-old mice once weekly for 4 weeks can decrease the incidence of invasive lesions by up to 85% compared to vehicle control while reverting glands to patterns of low grade intraepithelial neoplasia. PMR-116 rapidly inhibits proliferation in the Hi-MYC model with a 50% decrease in Ki67 observed 12 hours after oral administration. Conversely, PMR-116 showed minimal anti-tumour efficacy in the PTEN-null model of PCa suggesting that elevated MYC signalling may be required for optimal response. To further validate our promising GEMM results in more clinically relevant human-derived models, we used patient-derived xenografts lines we established from multidrug-resistant, metastatic PCa(4). PMR-116 treatment decreased tumour volume in all PDX tested including complete response in a line in which tumour volume decreased by ~90% compared to baseline. We believe this new RNA Pol I inhibitor shows promising results in a wide range of preclinical models of androgen receptor dependent and independent PCa and may exert higher efficacy in tumours expressing high levels of MYC. PMR-116 is currently in Phase I dose escalation trial in patient with solid tumours (ACTRN12620001146987).

Sanwu Baisan decoction inhibits colorectal cancer progression in mice by remodeling gut microbiota and tumorigenesis.

To uncover the anti-tumor effects and potential mechanism of Sanwu Baisan Decoction (, SWB) in treatment of colorectal cancer (CRC) in mice. Therapeutic effect was evaluated based on body weight gain, tumor volume, tumor growth inhibition rate, and histological changes and apoptosis in the tumor tissues. Anti-tumor immunity was studied by measuring plasma levels of anti-tumor cytokines, interleukin 6 (IL-6), interleukin 17 (IL-17), and interferon γ (IFN-γ). Gut morphological changes were evaluated by histological staining and tight junction proteins expressions. Gut microbiota composition was analyzed by 16S rRNA gene sequencing. Classical toll-like receptor 4 (TLR-4)/ cyclooxygenase 2 (COX-2)/ prostaglandin E2 (PGE-2) pathway was examined in colon tissue and tumor samples. SWB presented high anti-tumor efficacy of CRC in mice, which manifested as decreased tumor volume and increased tumor growth inhibition rate. This anti-tumor effect of SWB was associated with elevated plasma levels of anti-tumor immune cytokines (IL-6, IL-17, and IFN-γ). Further studies showed that SWB also increases the expression of occluding and promotes the abundance of gut probiotics, , , and . Moreover, results suggested that the anti-tumor effects of SWB might associate with inducing cancer cell apoptosis and inhibiting the TLR-4/COX-2/PGE-2 pathway in both colon tissue and tumor samples. SWB shows strong anti-tumor efficiency in mice with colorectal carcinoma, possibly through promoting the secretion of anti-tumor immune cytokines, inducing cancer apoptosis, maintaining the gut microbiota, and inhibiting tumorigenesis by inhibiting the TLR-4/COX-2/PGE-2 pathway.

Preclinical efficacy of NXP900, a YES1/SRC kinase inhibitor in esophageal squamous cancer models.

e15133 Background: NXP900 (eCF506) is a novel potent and selective SRC family kinase (SFK) inhibitor, (IC50 of 0.47 nM against YES1). NXP900 locks its target into its native “closed” conformation (type 1.5 inhibitor), thereby inhibiting both kinase activity and complex formation with protein partners (Temps et al. Cancer Res. 2021, 81, 5438-5450). In contrast, multi-kinase inhibitors, including dasatinib and bosutinib, block SRC in the active “open” conformation (type 1 inhibitors) promoting the association of SFK and signaling partners via allosteric facilitation of conformational protein activation (Higuchi et al. Cell Rep 2021, 34, 108876). YES1 gene amplification is prevalent in several squamous cancers including esophageal squamous cell carcinoma (ESCC), lung SCC, head and neck SCC, and bladder cancer, indicating that YES1 would be an attractive target in these cancer types. Moreover, crosstalk between YES1 and the Hippo pathway suggests that NXP900 may have a therapeutic potential in squamous cancers with Hippo pathway alterations. Methods: Animal strain: CD1 Nude mice (Charles River). Human ESCC cancer cell lines: KYSE70, OE21, KYSE410, KYSE30 and OE19 cells (Sigma), TE5, and TE14 (Riken). Xenograft tumors were generated by subcutaneous implantation on the right lower flank of the thigh at a cell density of 2x106 to 1x107 cells/mouse at 0.1 mL Matrigel/cell dilution volume per injection. Experiment groups: Vehicle, NXP900 (40 mg/kg); treatment: QD for 28 days, oral gavage. Colony formation assay: 500 cells of 4 cell lines (KYSE70, OE21, KYSE410 and KYSE30) and 1500 cells of 3 cell lines (OE19, TE5 and TE14) were seeded in 24 well plates in triplicates; and treated with NXP900 for 14 days followed by staining with crystal violet. Results: NXP900 strongly inhibited cell proliferation of KYSE70, KYSE410, KYSE30, OE21, OE19, TE5 and TE14 in a colony formation assay. NXP900 significantly inhibited the activating phosphorylation of SRC in KYSE70 cells at 10 nM, while no effect was observed on the inhibitory tyrosine residues on YES1/FYN at 250 nM. Oral administration of NXP900 in a KYSE70 xenograft mouse model with YES1 gene amplification, resulted in an average decrease of tumor volume of 71% while in the vehicle control group tumor volume increased by 472% (p ≤ 0.001), demonstrating significant tumor regression. On Day 27, a mean increase from baseline in body weight of 2.0% and 3.5% was seen in the NXP900 and control groups respectively, indicating good tolerability. Conclusions: NXP900 is a novel potent and selective YES1/SRC kinase inhibitor with subnanomolar IC50 against YES1. NXP900 has marked antitumor efficacy in esophageal carcinoma models in vitro and in vivo providing substantial proof of concept for targeting solid tumors with YES1 and Hippo pathway alterations. IND enabling studies for NXP900 have been completed.

Efficacy of STC-1010, a new allogenic cancer vaccine in colorectal cancer models.

e14661 Background: Colorectal cancer (CRC) is the second cause of cancer-related death worldwide. Recent tremendous progresses have installed immunotherapy as a treatment option and opened multiple ways to address therapeutic challenges for MSI or MSS CRC patients. Accordingly, Brenus-Pharma developed a therapeutic cancer vaccine, the STC-1010, basing on the technology by stimulating tumor cells (STC) with physical (irradiation and heat shock) and chemical (via standard-of-care (SoC) chemotherapy) stress, coupled with the haptenization for overexpressing tumor-related antigens. Methods: The mouse version of STC-1010 (mSTC-1010) vaccine prepared using two CRC mouse cell lines (CT26 and CMT93) and one pancreatic cancer mouse cell line (LTPA), previously showed encouraging results in pre-clinical studies on MSS CT26 ‘cold-tumor’ and anti-PD1 resistant MSI MC38 ‘hot-tumor’ murine models. mSTC-1010 associated with immunostimulant (cyclophosphamide and GM-CSF at low doses), combined or not with chemotherapy (FOLFOX or FOLFIRI) led to a significant decrease of tumor volume, a M1-oriented macrophage response (immunohistochemical, iNOS/CD163 &gt; 1), and an increase of T lymphocyte infiltration. Results: We confirmed these proof-of-concept efficacy with the human STC-1010 using three CRC human cell lines (HCT116, HT29 and Lovo). STC-1010 favored ex vivo an immune stimulation on human dendritic cells (DCs) which further primed CD8+ T cells to induce massive apoptosis of CRC cells (versus control). In HT29 in-ovo chicken embryo Chorio-Allantoid Membrane (CAM) assay, STC-1010 significatively increased IL-12, IL-2 and IFN-gamma expression (versus control) (p &lt; 0.02). Results from this immune reactive model showed significant increase of tumor necrosis (p = 0,0267), metastasis regression (-49%), and increase infiltration of CD4+, CD8+ compared to control group. Conclusions: The good tolerability of the STC-1010 vaccine in different models allows to plan a first-in-human phase I/II clinical trial with MSS and MSI-H metastatic CRC (mCRC) patients. A dose-escalation phase Ia (STC-1010 plus immunostimulant, associated to mFOLFOX6 w/o bevacizumab) will be performed with MSS mCRC patients to evaluate the safety and the recommended phase 2 trial dose (RP2D). A subsequent expansion phase IIa part will assess STC-1010 efficiency, associated with SoC in first-line setting for MSS patients, and in second-line setting after immunotherapy for MSI-H, dMMR or Lynch syndrome mCRC patients.

RNF220 promotes gastric cancer growth and stemness via modulating the USP22/wnt/β-catenin pathway

Gastric cancer (GC) is a prevalent malignancy that seriously threatens the health and life of patients. Although Ring finger 220 (RNF220) has been demonstrated to participate in the development of various cancers, its role and mechanism in GC remain undiscovered. The expression of RNF220 was determined by The Cancer Genome Atlas (TCGA) database and Western blot. Additionally, the overall survival (OS) and post-progression survival (PPS) were analyzed based on the levels of RNF220 in the TCGA database. The role and mechanism of RNF220 in growth and stemness were investigated using cell counting kit-8, colony formation, sphere-formation, co-immunoprecipitation, and Western blot experiments. Furthermore, the role of RNF220 was investigated in a xenografted mouse model. The expression of RNF220 was found to be upregulated in GC, which predicted unfavorable OS and PPS in patients with GC. Knockdown of RNF220 reduced cell viability, colony numbers, numbers of spheres formation, and the relative protein levels of Nanog, Sox2, and Oct4 in both AGS and MKN-45 cells. Moreover, overexpression of RNF220 increased cell viability and the numbers of spheres formation in MKN-45 cells. Mechanistically, RNF220 bound to USP22, and interference of RNF220 downregulated the Wnt/β-catenin axis via USP22, which was confirmed by the overexpression of USP22 in both cell lines. Furthermore, silencing of RNF220 significantly decreased tumor volume and weight, the level of Ki-67, and the relative protein levels of USP22, β-catenin, c-myc, Nanog, Sox2, and Oct4. Taken together, downregulation of RNF220 suppressed GC cell growth and stemness by downregulating the USP22/Wnt/β-catenin axis.

Serum lactate dehydrogenase concentration after transcatheter renal artery embolization correlates with reduction in renal angiomyolipoma volume.

The extent of renal angiomyolipoma (AML) volume reduction after renal transcatheter arterial embolization (TAE) varies between patients, with no predictive measure available. To determine whether the serum lactate dehydrogenase (LDH) concentration shortly after TAE correlates with the extent of tumor shrinkage. In a cohort of 36 patients undergoing prophylactic renal TAE for unruptured renal AML, we retrospectively acquired data from patient medical records, including serum LDH before and within 7 days after TAE and the tumor volume before and 12-36 months after TAE. The relationship between the serum level of LDH and reduction in tumor volume was evaluated using Spearman correlation analysis. The median LDH concentration was significantly higher after TAE than before (909.0 U/L vs. 186.5 U/L). This early post-TAE serum LDH level and LDH index (post-TAE LDH / pre-TAE LDH) correlated significantly and positively with the absolute decrease in tumor volume (both P < 0.0001). We observed no significant correlation between the relative tumor volume reduction and serum LDH level or LDH index. Serum LDH elevation occurs shortly after TAE and correlates with the extent of absolute decrease in AML volume at 12-36 months after TAE. Further large-scale studies are warranted to confirm the predictive role of post-TAE serum LDH level and LDH index in tumor shrinkage in patients with unruptured renal AML.

Kaempferitrin, a major compound from ethanol extract of Chenopodium ambrosioides, exerts antitumour and hepatoprotective effects in the mice model of human liver cancer xenografts.

This study aimed to investigate antitumour effect and possible toxicity of kaempferitrin, the major compound from ethanol extract of Chenopodium ambrosioides, in the mice model of human liver cancer xenografts. Forty mice bearing SMMC-7721 cells xenografts were divided into control group (not treated) and three groups orally administered with ethanol extract of C. ambrosioides, kaempferol (positive control) and kaempferitrin for 30 days. Antitumour effect was evaluated by measurement of tumour growth, histological examinations of tumours, flow cytometry detection of splenic CD19+ B lymphocytes and CD161+ Natural Killer cells, biochemical measurements of serum levels of tumour necrosis factor-α, interleukin-6, interferon-γ, malonaldehyde, 2,2-diphenyl-1-picrylhydrazyl and 2,2'-azinobis-(3-ethylbenz thiazoline-6-sulphonate) radicals. Toxicity was evaluated by histological examinations of livers and measurements of serum levels of aspartate transaminase, alanine transaminase, total bilirubin, direct bilirubin, malonaldehyde and hepatic malonaldehyde level. Kaempferitrin significantly (P < 0.05) decreased tumour volume, mass and cell number. Antitumour effect was due to induction of tumour cells necrosis and apoptosis, stimulation of splenic B lymphocytes, decreases of radicals and malonaldehyde. Kaempferitrin did not change liver structure, and decreased serum levels of transaminases, bilirubin, malonaldehyde and hepatic malonaldehyde level. Kaempferitrin exerts antitumour and hepatoprotective effects.

Protective effect of aqueous extract of Pleurotus eous against Dalton's lymphoma ascites tumor in mice

The antitumor efficacy of Pleurotus eous aqueous extract (PEAE) was investigated both in vitro and in vivo. The MTT test was used to determine in vitro cytotoxicity against the Dalton's Lymphoma Ascites (DLA) cell line. PEAE's in vivo antitumor effect was compared to that of the conventional drug cyclophosphamide in a DLA-induced solid tumor model. After 24 h following DLA inoculation, experimental animals were given PEAE (500 and 1000 mg/kg bw) and cyclophosphamide (CTX, 25 mg/kg bw) orally for 30 days. PEAE was also subjected to preliminary phytochemical screening as part of the research. PEAE has a high total phenolic (9.63 GAE mg/g) and total flavonoid (3.81 CAE mg/g) content, according to phytochemical analyses. The phytochemical components of PEAE were identified by HPTLC analysis, which revealed three phenolic and one flavonoid compound peaks. PEAE exhibited antioxidant capacity, as per ABTS and FRAP assays. At 1000 μg/mL, anti-proliferative activity against the DLA cell line was moderately inhibited. PEAE reduced tumor burden in a dose-dependent way. At 500 and 1000 mg/mL PEAE treatment, there was a significant decrease in tumor volume (62.47 and 72.13%), tumor weight (53.32 and 73.72%), and improved longevity (30.89 and 58.14%). PEAE restored normal haematological and serum biochemical profiles in a dose-dependent manner, with a concurrent decrease in lipid peroxides and an increase in enzymic and non-enzymic antioxidants. Major chemical components of PEAE may be responsible for the anticancer effect, which was attributed to its enhancing endogenous mechanism, according to this study. The usefulness of PEAE as a possible naturally sourced therapeutic target for tumor prevention is emphasised.

FBXW7 promotes autophagy and inhibits proliferation of oral squamous cell carcinoma.

F-box and WD repeat domain containing 7 (FBXW7) is a critical tumor suppressor. The expression of FBXW7 is decreased in oral squamous cell carcinoma (OSCC) tissues and shows diagnosis value. We aimed to investigate the influence of FBXW7 overexpression on OSCC cell proliferation and autophagy. In Balb/c nude mice, CAL27 xenograft tumor model was established. Western blot was employed to evaluate protein level. Messenger RNA level was analyzed by quantitative reverse transcription-polymerase chain reaction. Colony formation assay and MTT assay were employed to evaluate cell proliferation. FBXW7 expression was decreased in OSCC cell lines. FBXW7 inhibited cell proliferation of SCC9 and CAL27. FBXW7 increased Autophagy related 7 (Atg7), Beclin1 (BECN1), B-cell lymphoma 2 (BCL2) -associated X (BAX), BCL2 antagonist killer (BAK), and microtubule-associated protein 1 light chain 3 (LC3) levels and decreased MCL1 and BCL2 levels in CAL27 cells. FBXW7 decreased tumor volume and weight in CAL27 xenograft tumor model. FBXW7 increased BECN1, Atg7, and LC3 levels in CAL27 xenograft tumor model. In conclusion, decreased expression of FBXW7 is confirmed in diverse OSCC cell lines. The enhanced FBXW7 expression inhibits cancer cell proliferation and promotes autophagy in both OSCC cells and xenograft tumor model.

Actionable spontaneous antibody responses antagonize malignant progression in ovarian carcinoma

ObjectiveTo demonstrate that shared antibody responses in endometriosis and endometriosis-associated ovarian cancer spontaneously antagonize malignant progression and can be leveraged to develop future immunotherapies. MethodsB cells from cyopreserved clear cell ovarian carcinoma (CCC, n = 2), endometrioid ovarian carcinoma (EC, n = 2), and endometriomas (n = 2) were isolated, activated, and EBV-immortalized. Antibodies were purified from B cell supernatants and used for screening arrays containing most of the human proteome. Targets were prioritized based on accessibility (transmembrane or secreted proteins), expression in endometriosis and cancer, and concurrent IgA and IgG responses. We focused on antibodies targeting tumor-promoting syndecan binding protein (SDCBP) to demonstrate anti-tumor activity. Immunoblots and qPCR were performed to assess SDCBP expression in ovarian cancer and endometriosis cell lines and tumor samples. Recombinant IgG4 was generated using the variable heavy and light chains of dominant B cell receptors (BCRs) reacting against the extracellular domain of SDCBP, and used in in vivo studies in human CCC- and high-grade serous ovarian carcinoma (HGSOC)-bearing immunodeficient mice. ResultsNine accessible proteins detected by both IgA and IgG were identified in all samples - including SDCBP, which is expressed in ovarian carcinomas of multiple histologies. Administration of α-SDCBP IgG4 in OVCAR3 (HGSOC), TOV21G and RMG-I (CCC) tumor-bearing mice significantly decreased tumor volume compared to control irrelevant IgG4. ConclusionsSpontaneous antibody responses exert suboptimal but measurable immune pressure against malignant progression in ovarian carcinomas. Using tumor-derived antibodies for developing novel immunotherapeutics warrants further investigation.

Outcomes and Prognostic Factors in the Treatment of Intracanalicular Vestibular Schwannomas Using Gamma Knife Stereotactic Radiation.

No gold standard has been developed for the therapy of intracanalicular vestibular schwannomas (IVS). Options for treatment include a conservative approach, microsurgery, or radiosurgery. Although the efficacy of these treatment has been well-documented, little is known about the determinants of outcome in IVSs following radiosurgery. Therefore, we examined the results in relation to age, gender, tumor volume, distance to fundus, microcyst existence, and radiosensitivity in this group. In addition, we investigated possible predictors of facial nerve function and hearing preservation. Ninety-four patients with unilateral IVS were included in the evaluation (52 women and 42 males). The patients were separated into younger and older age groups based on their median age (55 years). The median IVS volume was 138 mm3, microcysts were identified in 16 tumors, and 63 tumors were adjacent to the fundus. The data were analyzed using Statistica software package ver. 13.3. At final follow-up, a statistically significant decrease in tumor volume and no statistically significant decline in hearing were noted, but no differences between age groups were found. The sex had no effect on overall tumor growth control, facial nerve preservation, or hearing preservation. Localization of IVS close to the fundus and the presence of tumor microcysts had no effect on the control of tumor growth, preservation of hearing, and sparing of facial nerve following radiosurgery. Cochlear dose had no influence on hearing preservation. Higher tumor volume was associated with its pseudoprogression during early follow-up and a greater risk of hearing loss. Age, sex, tumor volume, proximity to the fundus, and the existence of a microcyst were not predictive of radiosensitivity nor preservation of facial nerve function and hearing, based on the findings. There was no effect of cochlear dose on hearing. Initial greater tumor volume was associated with an increased probability of tumor pseudoprogression.

Co-administration with A1M does not influence apoptotic response of 177Lu-octreotate in GOT1 neuroendocrine tumors

Recombinant α1-microglobulin (A1M) is a proposed radioprotector during 177Lu-octreotate therapy of neuroendocrine tumors (NETs). To ensure a maintained therapeutic effect, we previously demonstrated that A1M does not affect the 177Lu-octreotate induced decrease in GOT1 tumor volume. However, the underlying biological events of these findings are still unknown. The aim of this work was to examine the regulation of apoptosis-related genes in GOT1 tumors short-time after i.v. administration of 177Lu-octreotate with and without A1M or A1M alone. Human GOT1 tumor-bearing mice received 30 MBq 177Lu-octreotate or 5 mg/kg A1M or co-treatment with both. Animals were sacrificed after 1 or 7 days. Gene expression analysis of apoptosis-related genes in GOT1 tissue was performed with RT-PCR. In general, similar expression patterns of pro- and anti-apoptotic genes were found after 177Lu-octreotate exposure with or without co-administration of A1M. The highest regulated genes in both irradiated groups compared to untreated controls were FAS and TNFSFRS10B. Administration of A1M alone only resulted in significantly regulated genes after 7 days. Co-administration of A1M did not negatively affect the transcriptional apoptotic response of 177Lu-octreotate in GOT1 tumors.

Abstract LB165: A novel PDX-based 2-stage screening platform can identify active drug combinations against KRAS-mutated colorectal cancer

Abstract Introduction: Targeting RASmut colorectal cancers (CRC) remains challenging and targeting has focused on the RAS-MAPK cascade. MEK inhibitors for KRASmut tumors were not successful in vivo or in clinic as they slowed tumor growth, but did not cause regression at clinically achievable doses, however, potential for synergy has been shown. In vivo modeling commonly guides decisions to advance to the clinic but these studies are heterogeneously conducted, with rare use of statistically justified sample sizes or prespecified alternate hypotheses. The purpose of this study was to develop a robust PDX screening platform for pre-clinical evaluation of combination strategies, and pilot it with MEK inhibitor combinations. Methods: The screening model was based on Simon's two-stage design, with alternate hypothesis of 30% response rate (null hypothesis of 5% response rate). Stage 1 involved testing drug combinations against 5 KRASmut PDX models. Drug combinations that demonstrated efficacy in Stage 1 (≥10% decrease in tumor volume at Day 22 post-treatment) were tested in Stage 2 against an additional 13 PDX models. The null hypothesis was rejected if ≥3/18 PDX models showed response. This design yields a type I error rate of 0.05 and power of 0.8. Twenty RAS-MAPK cascade inhibitor-based combinations were tested. RP2D drug doses were used. Results: In Stage 1, MEKi plus CDK4/6i combination demonstrated efficacy in 3/5 models. This effect was sustained in Stage 2 (9/13 models with ≥10% decrease in tumor volume) for a total of 12/18. MEKi/BETi was next best (total 4/18 models). MEKi/PARPi and MEKi/ERKi - 3/18. Two combinations (MEKi/TKi and MEKi/AKTi) passed Stage 1, but failed in Stage 2 (2/18 total). Other combinations did not meet efficacy threshold in Stage 1 and were deemed inactive. In an expansion study of various RASmut PDX models (6 codon 12/13 KRASmut, 5 codon 61/146 RASmut and 4 RASwt), trametinib/palbociclib differentially attenuated tumor growth relative to untreated controls and caused tumor regression in all tested PDX models. Protein expression analysis (RPPA) demonstrated increases in cell cycle regulators (Cyclin-B1, FOXM1, PLK1) in non-responders, and higher pMEK and FOXO3 protein levels in responders. Combination treatment resulted in decreased expression of MAPK/ERK and CDK4/6 pathway-related proteins. mRNA expression analysis (GSEA) revealed that MEKi-resistant PDX models were enriched in cell cycle, ERK, mTORC1, ER stress and DDR signaling pathways. Primary drug combination toxicity (weight loss) was most pronounced with trametinib/palbociclib compared to tram or palbo alone. Using in vivo dose/response matrix screening, we maintained &amp;gt;90% efficacy while significantly reducing toxicity (decreasing weight loss from &amp;gt;15% to &amp;lt;10%) by decreasing palbociclib dose and maintaining tram dose intensity. Conclusions: The two-stage screening design demonstrated efficacy, time and cost-efficiency in drug combination screening. Efficacy of MEKi/CDK4/6i, MEKi/PARPi and MEKi/BETi combinations in RASmut CRCs was confirmed. These combinations are now being explored in prospective clinical trials. Citation Format: Alexey Sorokin, Preeti Kanikarla Marie, Fengqin Gao, Zhensheng Liu, David Menter, Scott Kopetz. A novel PDX-based 2-stage screening platform can identify active drug combinations against KRAS-mutated colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 2 (Clinical Trials and Late-Breaking Research); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(8_Suppl):Abstract nr LB165.

Abstract LB018: Therapeutic efficacy of inhibition of specific sirtuins against melanoma in BrafV600E/PtenNULL and PDX models

Abstract Melanoma is a highly immunogenic malignancy and one of the deadliest skin cancers due to its ability to metastasize and its resistance to existing therapies. Current treatment regimens include immunotherapies as well as targeted therapies (e.g. BRAF and MEK inhibitors). However, these immuno- or targeted therapies have been associated with acquired resistance and, therefore, failure of therapy. Therefore, development of novel mechanistically-targeted therapies is of paramount importance for an efficient management of this neoplasm. Sirtuins, a seven-member family of class III histone deacetylases, have been implicated in the development/progression of multiple cancers, including melanoma. Previous studies from our laboratory and elsewhere have shown the pro-proliferative functions of sirtuins SIRT1 and SIRT3 in melanoma. We have also shown that the small molecule inhibitor 4’-bromoresveratrol (4’-BR; co-inhibitor of SIRT1 and SIRT3) has antiproliferative effects in melanoma cell lines as well as in a BrafV600E/PtenNULL mouse model of melanoma. This study was designed to further expand on our previous findings and to determine the therapeutic significance of SIRT1 and SIRT3 in melanoma. To determine the effect of specific inhibition of SIRT3 on melanoma progression, we treated BrafV600E/PtenNULL mice with 100 μg small interfering RNA (siRNA) against SIRT3 (siSIRT3) or its non-targeting control (siNTC) twice weekly (intraperitoneal injections for 5 weeks). We found a trend of decreased tumor volumes in the siSIRT3-treated mice, though not significant. A similar trend was seen in the final tumor weight of these mice. In the next series of experiments, we used two human melanoma patient-derived xenografts (PDXes) to compare the effect of 4’-BR or siSIRT3 on melanoma tumor growth. Similar to our published study in the BrafV600E/PtenNULL mice, we found that 4’-BR treatment (50 mg/kg, via intraperitoneal injection, twice weekly for 5 weeks) resulted in a significant decrease in tumor growth when compared to vehicle control mice. Additionally, the final tumor weight was significantly decreased in the 4’-BR group. However, the siSIRT3 treatments resulted in a decrease but non-significant decrease in melanoma tumor growth or final weights, supporting our observations in BrafV600E/PtenNULL mice. Considering the lung is a common site for metastasis in melanoma, metastatic nodules in the lungs were quantified in one of our PDX models. We observed a decreased number in both the siSIRT3 and 4’-BR groups vs their respective controls. Overall, our data suggests that targeting SIRT3 alone may not be sufficient for melanoma treatment, and that the concomitant inhibition of SIRT1 and SIRT3 (and potential other sirtuins with pro-proliferative functions in melanocytic cells) may be better for melanoma management. Indeed, additional research is needed to validate our findings in relevant models. Citation Format: Karla Anaya Aldrete, Gabriella R. Zaemisch, Mary A. Ndiaye, Gagan Chhabra, Nihal Ahmad. Therapeutic efficacy of inhibition of specific sirtuins against melanoma in BrafV600E/PtenNULL and PDX models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 2 (Clinical Trials and Late-Breaking Research); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(8_Suppl):Abstract nr LB018.