Combination Treatment Strategies Research Articles

A bispecific antibody targeting HER2 and CLDN18.2 eliminates gastric cancer cells expressing dual antigens by enhancing the immune effector function.

Gastric cancer (GC) is widely regarded as one of the toughest cancers to treat. Trastuzumab, which targets the human epidermal growth factor receptor 2 (HER2) for GC treatment, has demonstrated clinical success. However, these patients have a high likelihood of developing resistance. Additionally, Claudin18.2 (CLDN18.2) is a promising emerging target for GC treatment. Therefore, therapies that simultaneously target both HER2 and CLDN18.2 targets are of great significance. Here, we constructed a bispecific antibody targeting both HER2 and CLDN18.2 (HC-2G4S; BsAb), which displayed satisfactory purity, thermostability and enhancing antibody-dependent cell-mediated cytotoxicity (ADCC) activity. In a tumor spheroids model of GC, BsAb demonstrated greater therapeutic efficacy than monoclonal antibodies (mAb) or combination treatment strategies. We propose that the enhanced anti-tumor potency of BsAbs in vivo is due to the monovalent binding of single-chain antibodies to more targets due to weaker affinity, resulting in a more potent immune effect function. Therefore, HC-2G4S could be a productive agent for treating GC that is HER2-positive, CLDN18.2-positive, or both, with the potential to overcome trastuzumab resistance and provide significant clinical benefits and expanded indications.

Preclinical exploration of the DNA damage response pathway using the interactive neuroblastoma cell line explorer CLEAN.

Neuroblastoma (NB) is the most common cancer in infancy with an urgent need for more efficient targeted therapies. The development of novel (combinatorial) treatment strategies relies on extensive explorations of signaling perturbations in neuroblastoma cell lines, using RNA-Seq or other high throughput technologies (e.g. phosphoproteomics). This typically requires dedicated bioinformatics support, which is not always available. Additionally, while data from published studies are highly valuable and raw data (e.g. fastq files) are nowadays released in public repositories, data processing is time-consuming and again difficult without bioinformatics support. To facilitate NB research, more user-friendly and immediately accessible platforms are needed to explore newly generated as well as existing high throughput data. To make this possible, we developed an interactive data centralization and visualization web application, called CLEAN (the Cell Line Explorer web Application of Neuroblastoma data; https://ccgg.ugent.be/shiny/clean/). By focusing on the regulation of the DNA damage response, a therapeutic target of major interest in neuroblastoma, we demonstrate how CLEAN can be used to gain novel mechanistic insights and identify putative drug targets in neuroblastoma.

Analysis of the effectiveness of various methods of managing patients with endometriosis and justification for long-term personalized anti-relapse therapy with dydrogesterone as part of their combination treatment strategy

Analysis of the effectiveness of various methods of managing patients with endometriosis and justification for long-term personalized anti-relapse therapy with dydrogesterone as part of their combination treatment strategy

Tanreqing injection inhibits stemness and enhances sensitivity of non-small cell lung cancer models to gefitinib through ROS/STAT3 signaling pathway.

Resistance to epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) has emerged as a significant obstacle in managing patients with EGFR-mutant non-small-cell lung cancer (NSCLC), necessitating the exploration of novel therapeutic approaches. Tanreqing injection (TRQ) is a kind of Chinese patent medicine known for its heat-clearing and detoxifying properties. Studies have shown a correlation between tumor drug resistance and enrichment of cancer stem cells (CSCs). We aim to investigate the feasibility of TRQ enhancing sensitivity to gefitinib by targeting CSCs and reactive oxygen species (ROS). In our study, TRQ significantly inhibited cell proliferation in gefitinib-resistant non-small-cell lung cancer (NSCLC) models including 2D cell lines, 3D cell spheres, tumor-bearing animal and organoids. Compared with the gefitinib group alone, addition of TRQ elevated ROS levels, attenuated upregulation of the protein levels of sex-determining region Y-box 2 (SOX2) and aldehyde dehydrogenase 1 family member A1 (ALDH1A1) induced by gefitinib treatment, and inhibited the phosphorylation of signal transducer and activator of transcription 3 (STAT3). Scavenging ROS could restore tumor stemness, attenuate the inhibitory effect on the phosphorylation of STAT3, and promote cell proliferation. These results suggested that TRQ could enhance sensitivity of NSCLC models to gefitinib, providing a new combined treatment strategy.

Efficacy of photodynamic therapy using hematoporphyrin derivative nanomedicine on hepatocellular carcinoma cells.

Objective: To demonstrate the efficacy of photodynamic therapy (PDT) using hematoporphyrin derivative (HPD) nanomedicine in combination with conventional chemotherapy based on gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA) magnetic resonance imaging (MRI) for hepatocellular carcinoma (HCC) therapy. Methods: HPD nanomedicine was prepared, and the cytotoxicity of HPD nanomedicine at different concentrations on HCC cells and the half-maximal inhibitory concentration (IC50) were analyzed. Sixty HCC patients who visited our hospital from 2021 to 2023 were retrospectively analyzed. Patient data were analyzed, with 30 cases in control group (CG) receiving conventional chemotherapy for HCC, and 30 cases in observation group (OG) receiving conventional chemotherapy combined with HPD nanomedicine PDT. Gd-DTPA MRI was utilized to monitor the morphological and biological characteristics of the lesions in patients. After treatment completion, the long-term efficacy of patients and the levels of bcl-2 and bax proteins in primary HCC cells were evaluated. Results: The IC50 values of HPD on HepG2 cell proliferation and the cell inhibition rates gradually increased with increasing doses of HPD (50 μM, 25 μM, 12.5 μM, 6.25 μM, 3.13 μM, 1.56 μM, 0.78 μM). HPD exhibited great anti-proliferative effects on HepG2 cells at relatively low concentrations. The differences in expression rates of bcl-2 protein and bax protein between groups were considerable (P<0.05). There were neglectable changes in AST and ALT levels between the two groups before treatment, but they were markedly reduced after treatment versus before treatment (P<0.05), with OG showing considerably lower levels than CG after treatment (P<0.05). Additionally, patients in OG exhibited better survival rates after the course of treatment versus those in CG. Conclusion: This study demonstrates that the combination of conventional chemotherapy based on Gd-DTPA MRI with HPD nanomedicine PDT greatly improves the efficacy of treatment for HCC patients. This combined treatment strategy not only enhances therapeutic outcomes but also alleviates adverse reactions associated with conventional treatment, providing a novel approach for future research in the treatment of HCC.

Advancing treatment efficacy: combined therapy of eribulin, anlotinib, and camrelizumab in advanced or metastatic retroperitoneal liposarcoma.

Retroperitoneal liposarcoma (RLPS) typically shows limited response to standard chemotherapy, presenting a challenge in treating advanced or metastatic RLPS. This study aimed to evaluate the potential advantages of a combined therapeutic strategy utilizing eribulin, anlotinib, and camrelizumab. Between December 2020 and March 2023, this retrospective study enrolled patients with advanced or metastatic RLPS who received treatment at Peking University Cancer Hospital Sarcoma Center. The treatment regimen involved eribulin plus anlotinib and camrelizumab administered every 3 weeks (Q3W). Efficacy was assessed following the Response Evaluation Criteria in Solid Tumors version 1.1, while safety was evaluated using the Common Terminology Criteria for Adverse Events version 5.0. The study included 47 patients with RLPS with a median age of 55.5 years. Patients received a median of 4.5 (range, 2-21) cycles of treatment. Notably, partial response was observed in 8 patients (18.2%), while 25 (56.8%) exhibited stable disease. The objective response rate (ORR) and disease control rate were 18.2% and 75%, respectively. Significant differences in ORR were observed among histological subtypes (well-differentiated vs de-differentiated vs myxoid: 0 vs 17.9% vs 50%; p = 0.039). Six patients underwent surgery before disease progression, and one patient with myxoid liposarcoma (MLPS) had a pathological complete response. With a median follow-up of 21.8 (range, 2.7-30.7) months, the median progression-free survival (mPFS) was 6.9 (95% confidence interval (CI), 4.7-9.1) months, and the 6-month PFS rate was 60.5%. Based on various histological subtypes, the mPFS was 8.4 (95% CI, 4.1-12.7) months with well-differentiated liposarcoma, 5.8 (95% CI, 3.3-8.3) months with de-differentiated liposarcoma and not reached with MLPS, respectively. Treatment-related adverse events (TRAEs) of any grade occurred in 36 (76.6%) patients, with grade 3 or higher TRAEs in 21 (44.7%) patients. The most common TRAEs were neutropenia (53.2%), proteinuria (21.3%), and anorexia (21.3%). The combined treatment strategy involving eribulin, anlotinib, and camrelizumab showed promising efficacy and manageable safety in patients with advanced or metastatic RLPS, particularly in those with MLPS.

Combined strategies with PARP inhibitors for the treatment of BRCA wide type cancer.

Genomic instability stands out as a pivotal hallmark of cancer, and PARP inhibitors (PARPi) emerging as a groundbreaking class of targeted therapy drugs meticulously crafted to inhibit the repair of DNA single-strand breaks(SSB) in tumor cells. Currently, PARPi have been approved for the treatment of ovarian cancer, pancreatic cancer, breast cancer, and prostate cancer characterized by homologous recombination(HR) repair deficiencies due to mutations in BRCA1/2 or other DNA repair associated genes and acquiring the designation of breakthrough therapy. Nonetheless, PARPi exhibit limited efficacy in the majority of HR-proficient BRCA1/2 wild-type cancers. At present, the synergistic approach of combining PARPi with agents that induce HR defects, or with chemotherapy and radiotherapy to induce substantial DNA damage, significantly enhances the efficacy of PARPi in BRCA wild-type or HR-proficient patients, supporting extension the use of PARPi in HR proficient patients. Therefore, we have summarized the effects and mechanisms of the combined use of drugs with PARPi, including the combination of PARPi with HR defect-inducing drugs such as ATRi, CHKi, HR indirectly inducing drugs like VEGFRi, CDKi, immune checkpoint inhibitors and drugs instigating DNA damage such as chemotherapy or radiotherapy. In addition, this review discusses several ongoing clinical trials aimed at analyzing the clinical application potential of these combined treatment strategies.

Combinational Antitumor Strategies Based on the Active Ingredients of Toad Skin and Toad Venom.

A multidrug combination strategy is an important mean to improve the treatment of cancer and is the mainstream scheme of clinical cancer treatment. The active ingredients of traditional Chinese medicine, represented by toad skin and toad venom, have the advantages of high efficiency, low toxicity, wide action and multiple targets and have become ideal targets in combined treatment strategies for tumors in recent years. Toad skin and toad venom are traditional Chinese animal medicines derived from Bufo bufo gargarizans Cantor or Bufo melanostictus Schneider that have shown excellent therapeutic effects on the treatment of various cancers and cancer pain as adjuvant antitumor drugs in clinical practice. The involved mechanisms include inducing apoptosis, arresting the cell cycle, inhibiting cell proliferation, migration and invasion, inhibiting tumor angiogenesis, reversing the multidrug resistance of tumor cells, and regulating multiple signaling pathways and targets. Moreover, a multidrug combination strategy based on a nanodelivery system can realize the precise loading of the active ingredients of toad skin or toad venom and other antitumor drugs and carry drugs to overcome physiological and pathological barriers, complete efficient enrichment in tumor tissues, and achieve targeted delivery to tumor cells and the controlled release of drugs, thus enhancing antitumor efficacy and reducing toxicity and side effects. This article reviewed the clinical efficacy and safety of the combination of toad skin and toad venom with chemotherapeutic drugs, targeted drugs, analgesics and other drugs; evaluated the effects and mechanisms of the combination of toad skin and toad venom with chemotherapy, targeted therapy, radiotherapy or hyperthermia, traditional Chinese medicine, signaling pathway inhibitors and other therapies in cell and animal models; and summarized the codelivery strategies for the active ingredients of toad skin and toad venom with chemotherapeutic drugs, small-molecule targeted drugs, monoclonal antibodies, active ingredients of traditional Chinese medicine, and photodynamic and photothermal therapeutic drugs to provide a basis for the rational drug use of toad skin and toad venom in the clinic and the development of novel drug delivery systems.

Methods behind oncolytic virus-based DC vaccines in cancer: Toward a multiphase combined treatment strategy for Glioblastoma (GBM) patients.

Glioblastoma (GBM) remains an orphan cancer disease with poor outcome. Novel treatment strategies are needed. Immunotherapy has several modes of action. The addition of active specific immunotherapy with dendritic cell vaccines resulted in improved overall survival of patients. Integration of DC vaccination within the first-line combined treatment became a challenge, and immunogenic cell death immunotherapy during chemotherapy was introduced. We used a retrospective analysis using real world data to evaluate the complex combined treatment, which included individualized multimodal immunotherapy during and after standard of care, and which required adaptations during treatment, and found a further improvement of overall survival. We also discuss the use of real world data as evidence. Novel strategies to move the field of individualized multimodal immunotherapy forward for GBM patients are reviewed.

Effectiveness and safety of vascular intervention plus lenvatinib versus vascular intervention alone for hepatocellular carcinoma patients with portal vein tumor thrombus: a retrospective comparative study.

This study aimed to assess the effectiveness and safety of vascular intervention combined with lenvatinib versus vascular intervention alone in the treatment of advanced hepatocellular carcinoma (HCC) with portal vein tumor thrombus (PVTT), and to identify prognostic factors associated with the treatment outcomes. We conducted a retrospective analysis of data from 92 patients with advanced HCC and PVTT who were treated between February 2016 and February 2023. Among them, 56 patients underwent vascular intervention alone (transarterial chemoembolization, TACE), while 36 patients received vascular intervention (TACE or hepatic arterial infusion chemotherapy [HAIC]) combined with lenvatinib. The primary outcomes included progression-free survival (PFS), overall survival (OS), and objective response rate (ORR). Survival rates were estimated by the Kaplan-Meier method, and confounders were adjusted using inverse probability of treatment weighting (IPTW). Prognostic factors were determined through the Cox regression model. The median follow-up duration was 20.07 months (interquartile range: 6.41-25.36). The combination therapy group had a significantly longer median PFS (11.00 vs. 5.00 months, P<0.05) and OS (12.91 vs. 6.83 months, P<0.05) in comparison to the monotherapy group, and these findings remained consistent after IPTW matching. Moreover, the combination therapy group showed a higher ORR (55.56% vs. 26.79%, P<0.05) based on mRECIST criteria. Cox multivariate analysis identified extrahepatic metastasis and maximum tumor diameter as risk factors for PFS, while age, tumor number, and maximum tumor diameter influenced OS. Combined treatment emerged as a protective factor for OS. In the combination therapy group, hypertension was the most frequent adverse event, with grade 3 or 4 adverse events occurring rarely. The combination of vascular intervention with lenvatinib has demonstrated improved PFS and OS in advanced HCC patients with PVTT, and its safety profile appears to be acceptable. Adoption of this combined treatment strategy at an earlier stage may enhance patient outcomes.

Характеристика и управление нежелательными реакциями у пациентов с распространенным раком эндометрия, которые получают комбинацию ленватиниб плюс пембролизумаб

Background. Lenvatinib plus pembrolizumab significantly improved efficacy compared with chemotherapy in patients with advanced endometrial cancer (aEC) regardless of microsatellite instability status or histologic subtype, who had disease progression following prior platinum-based therapy, in Study-309/KEYNOTE-775. The safety profile of the combination was generally consistent with that of each monotherapy drug and of the combination in patients with endometrial cancer and other solid tumors. Given the medical complexity of patients with aEC, this paper aims to characterize key adverse reactions (ARs) of the combination treatment and review management strategies, providing a guide for AR management to maximize anticancer benefits and minimize treatment discontinuation. Materials and methods. In Study-309/KEYNOTE-775, patients received lenvatinib (20 mg orally once daily) plus pembrolizumab (200 mg intravenously every 3 weeks) or chemotherapy (doxorubicin or paclitaxel). The incidence and median time to the first onset of ARs, dose modifications, and concomitant medications are described. Key ARs characterized include hypothyroidism, hypertension, fatigue, diarrhea, musculoskeletal disorders, nausea, decreased appetite, vomiting, stomatitis, weight decreased, proteinuria, and palmar-plantar erythrodysesthesia syndrome. Results. As expected, the most common any-grade key ARs included: hypothyroidism, hypertension, fatigue, diarrhea, and musculoskeletal disorders. Grades 3-4 key ARs with incidence ≥10% included: hypertension, fatigue, and weight decreased. Key ARs first occurred within approximately 3 months of treatment initiation. AR management strategies consistent with the prescribing information and the study protocol are discussed. Conclusion. Successful AR management strategies for lenvatinib plus pembrolizumab include education of the patient and entire treatment team, preventative measures and close monitoring, and judicious use of dose modifications and concomitant medications.

The Biological and Clinical Role of the Telomerase Reverse Transcriptase Gene in Glioblastoma: A Potential Therapeutic Target?

Glioblastoma IDH-wildtype represents the most lethal and frequent primary tumor of the central nervous system. Thanks to important scientific efforts, we can now investigate its deep genomic assessment, elucidating mutated genes and altered biological mechanisms in addition to its clinical aggressiveness. The telomerase reverse transcriptase gene (TERT) is the most frequently altered gene in solid tumors, including brain tumors and GBM IDH-wildtype. In particular, it can be observed in approximately 80-90% of GBM IDH-wildtype cases. Its clonal distribution on almost all cancer cells makes this gene an optimal target. However, the research of effective TERT inhibitors is complicated by several biological and clinical obstacles which can be only partially surmounted. Very recently, novel immunological approaches leading to TERT inhibition have been investigated, offering the potential to develop an effective target for this altered protein. Here, we perform a narrative review investigating the biological role of TERT alterations on glioblastoma and the principal obstacles associated with TERT inhibitions in this population. Moreover, we discuss possible combination treatment strategies to overcome these limitations.

PEN-coated superparamagnetic iron-mediated delivery of siSnail2 to inhibit metastasis and promote ferroptosis in the treatment of cancer

Cancer represents a significant global public health challenge, and conventional cancer therapies such as surgery and chemoradiotherapy are not enough due to the increased complexity of cancer. Nanotechnology has the potential to revolutionize tumor treatments by integrating gene therapy, tumor targeting, and drug delivery. In this study, we demonstrated that Snail2 plays a crucial role in the migration and invasion of lung and liver carcinoma. We proposed a novel approach to synergize the aminated crosslinking dextran coat of superparamagnetic iron oxide nano worms (CLIO-NH2, CN) with small interfering Snail2 RNA (siSnail2). The efficiency of siSnail2 delivery was significantly improved by coating CN with N-Isopropylacrylamide-modified polyethylenimine (CNP). In vitro, experiments revealed that CNP@siSnail2 effectively inhibited cancer cell EMT, migration, and invasion. Moreover, CNP@ siSnail2 promoted cancer cell death through various mechanisms, including apoptosis and ferroptosis. The combination of CNP@ siSnail2 and cisplatin significantly improved the anti-tumor effect of the treatment. Animal models demonstrated that the combined treatment of CNP@ siSnail2 and cisplatin resulted in excellent tumor inhibition effects. Our findings provide a potential combined treatment strategy for cancer therapy.

Electroacupuncture combined with wet compress formula ameliorates upper limb dysfunction associated with stroke: A retrospective analysis of 126 cases

ObjectivesUpper limb motor dysfunction (ULMD) is one of the most common complications of ischemic stroke (IS). Electroacupuncture (EA) is a noninvasive procedure that has the potential to manage symptoms associated with IS. To improve the treatment effects of EA, our hospital performed combined treating strategy against ULMD by subjecting IS patients to both EA and external application of wet compress formula (WCF). In the current analysis, the potential improving effects of the combined treatment against ULMD were evaluated. Materials and methods126 patients with ULMD induced by IS handled with normal rehabilitation treatment, EA treatment alone, and EA combined with WCF respectively were enrolled in the current analysis. The clinicopathological information and changes in motor function assessment scales, including Visual analogue (VAS), Fugl-Meyer assessment-upper extremity (FMA-UA), and Modified Barthel index (MBI) scales were collected and the difference between different treating strategies was assessed. ResultsAll the treating strategies improved the values of VAS, FMA-UA, and MBI scales, with combined treating strategy showing the strongest improving effects, and traditional rehabilitation strategy showing the weakest effects. Moreover, the assessment of hand and wrist motor function by FMA-UE also showed that the combined treatment strategy has significantly stronger improving effects against ULMD compared with other strategies. ConclusionsThe current analysis showed that the use of external application of WCF could substantially increase the treating effects of EA on ULMD induced by IS without severe side effects, which could guide the future clinical management of motor dysfunction.

The current status and future of PD-L1 in liver cancer.

The application of immunotherapy in tumor, especially immune checkpoint inhibitors (ICIs), has played an important role in the treatment of advanced unresectable liver cancer. However, the efficacy of ICIs varies greatly among different patients, which has aroused people's attention to the regulatory mechanism of programmed death ligand-1 (PD-L1) in the immune escape of liver cancer. PD-L1 is regulated by multiple levels and signaling pathways in hepatocellular carcinoma (HCC), including gene variation, epigenetic inheritance, transcriptional regulation, post-transcriptional regulation, and post-translational modification. More studies have also found that the high expression of PD-L1 may be the main factor affecting the immunotherapy of liver cancer. However, what is the difference of PD-L1 expressed by different types of cells in the microenvironment of HCC, and which type of cells expressed PD-L1 determines the effect of tumor immunotherapy remains unclear. Therefore, clarifying the regulatory mechanism of PD-L1 in liver cancer can provide more basis for liver cancer immunotherapy and combined immune treatment strategy. In addition to its well-known role in immune regulation, PD-L1 also plays a role in regulating cancer cell proliferation and promoting drug resistance of tumor cells, which will be reviewed in this paper. In addition, we also summarized the natural products and drugs that regulated the expression of PD-L1 in HCC.

The Genomic Landscape of Urothelial Carcinoma with High and Low ERBB2 Expression.

Recent data suggests that HER2-targeted treatment is efficacious in urothelial carcinoma (UC). We investigated the genomic, transcriptomic, and immune landscapes and clinical outcomes in UC segmented by ERBB2 expression. NextGen DNA/RNA sequencing was performed for 4743 UC tumors. A total of 3% (124/4125) of tumors had HER2 IHC and whole transcriptome sequencing (WTS) data. ERRB2-high and -low tumors were defined by ≥75th and <25th percentiles of ERBB2 expression, respectively. PD-L1 (SP142) positive staining was defined as ≥2+ and ≥5%. HER2 (4B5) positive staining was defined as ≥3+ and >10% or 2+ and >10% with positive HER2 in situ hybridization (ISH). Of the patients who were ERBB2-high, 79% (61/77) were HER2 positive via IHC. Tumors from lower tract UC had higher ERBB2 expression compared to upper tract UC (50 v 40 median TPM (mTPM), p < 0.001). ERBB2 expression was similar between primary and metastatic tumors (47 v 47 mTPM, p = 0.95). ERBB2-high tumors had a higher prevalence of pathogenic mutations in pTERT, ERBB2, and ELF3 versus ERBB2-low tumors, p < 0.001. ERBB2-high tumors had higher expressions of ADC target genes NECTIN4 (12 v 8 mTPM) and TACSTD2 (366 v 74 mTPM) versus ERBB2-low (p < 0.001), as well as better overall survival from time of tissue sampling than ERBB2-low (HR 1.71, p < 0.001). Our study demonstrated a high concordance between HER2 expression by IHC and ERBB2 gene expression by WTS in UC. Differences in ADC target expression between ERBB2-high vs. ERBB2-low UC may provide a rationale for combination treatment strategies with HER2-ADC. The association between high ERBB2 expression and survival advantage warrants further investigation.

FGF19/FGFR4 signaling contributes to hepatocellular carcinoma survival and immune escape by regulating IGF2BP1-mediated expression of PD-L1

Immune-checkpoint blockade (ICB) therapies have been widely used in clinical treatment of cancer patients, but only 20–30% of patients benefit from immunotherapy. Therefore, it is important to decipher the molecular mechanism of resistance to ICB and develop new combined treatment strategies. PD-L1 up-regulation in tumor cells contributes to the occurrence of immune escape. Increasing evidence shows that its transcription level is affected by multiple factors, which limits the objective response rate of ICB. Fibroblast growth factor 19 (FGF19), a member of the fibroblast growth factor family, is widely involved in the malignant progression of many tumors by binding to fibroblast growth factor receptor 4 (FGFR4). In this study, we confirmed that FGF19 acts as a driver gene in hepatocellular carcinoma (HCC) progression by binding to FGFR4. The up-regulation of FGF19 and FGFR4 in HCC is associated with poor prognosis. We found that FGF19/FGFR4 promoted the proliferation and invasion of HCC cells by driving IGF2BP1 to promote PD-L1 expression. Knockdown of FGFR4 significantly reduced the expression of IGF2BP1/PD-L1 and inhibited the proliferation and invasion of HCC cells. These biological effects are achieved by inhibiting the PI3K/AKT pathway. The combination of FGFR4 knockdown and anti-PD-1 antibody greatly suppressed tumor growth and enhanced the sensitivity of immunotherapy, highlighting the clinical significance of FGF19/FGFR4 activation in immunotherapy.

Abstract C119: Combining forces: Integrating engineered bacterial therapeutics with targeted therapies for advanced-stage non-small cell lung cancer

Abstract Currently there are about 400 single-agent targeted therapies in various stages of clinical trials for non-small cell lung cancer (NSCLC) worldwide. However, less than 10% of them have been utilized in combination treatment to improve efficacy of advanced-stage NSCLC due to safety issues. As a result, emerging and safe treatment modalities such as engineered bacteria therapy, commonly known as “bugs as drugs”, in ongoing clinical trials (NCT00004988, NCT04589234, NCT05038150) for advanced-NSCLCs - have not been combined with current standards of care. We hypothesized that If advanced-stage NSCLC tumors are dependent on altered growth signaling upon single-agent bacteria therapy, blocking those signaling with current targeted therapy may provide a promising combination treatment strategy to achieve better efficacy. To test this, we first treated NSCLC-derived spheroids with engineered bacteria producing Theta toxin after localizing in the hypoxic core and eliminating spheroids from inside. Second, we characterized the signaling pathways of bacteria-treated NSCLC spheroids by RNA-seq followed by Gene Set Enrichment Analysis. Third, we blocked altered signaling with current targeted therapies to achieve better efficacy. Finally, we designed an optimum combination treatment and validated it in vivo in xenografted NSCLCs. We found that bacterially secreted Theta toxin significantly altered PI3K/AKT/mTOR signaling, cell cycle checkpoint and DNA repair pathways (normalized p-value &amp;lt; 0.5 and falls discovery rate q-value &amp;lt; 0.5) in multiple NSCLC spheroids, including one established from a chemotherapy and radiation-resistant tumor. We chose current targeted inhibitors of AKT (MK2206), CHK (AZD7762), WNT (IWR-1), ERK (SCH772984), MEK (Selumetinib), and 2 chemotherapy drugs (paclitaxel, pemetrexed) to treat these bacterially-treated NSCLC spheroids. We found that blocking AKT or CHK signaling in combination with bacteria therapy significantly decreased (p&amp;lt;0.002) NSCLC spheroid viability. Honing in on AKT signaling, we validated bacterially secreted Theta toxin induced AKT phosphorylation in NSCLC cells in vitro that we were able to block with MK2206 treatment. Finally, we tested this combination of bacterially secreted Theta toxin and MK2206 in xenografted NSCLC tumors. The combination treatment significantly improved efficacy in all tumors (p&amp;lt;0.001) compared to single-agent therapy (either engineered bacteria or MK2206 alone) without any additional toxicity suggesting a promising translational treatment strategy. We conclude that our modular experimental and analytical pipeline can be exploited to characterize engineered bacteria therapies and combine them with specific targeted therapy to expedite the translation of an untapped area of drug development with biological therapeutic agents for advanced-stage NSCLC. Citation Format: Dhruba Deb, Tal Danino. Combining forces: Integrating engineered bacterial therapeutics with targeted therapies for advanced-stage non-small cell lung cancer [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr C119.

Abstract A003: A novel treatment strategy for high-risk and relapse/refractory hepatoblastoma

Abstract Background: Patients with metastatic, treatment-refractory, and relapsed hepatoblastoma (HB) have survival rates of less than 50% due to limited treatment options. To better understand these aggressive phenotypes, our lab has developed a preclinical testing pipeline consisting of patient-derived spheroids (PDSp) and orthotopic xenograft models for chemotherapy and targeted therapy testing. We hypothesized that with this preclinical pipeline we could find an effective combination treatment strategy utilizing pan-histone deacetylase (HDAC) inhibition. Methods: RNA sequencing, microarray, NanoString, and immunohistochemistry (IHC) data of patient HB samples were analyzed for expression of all HDAC classes. HB cell lines were used to screen HDAC inhibitors. PDSp were used to screen which combination of standard chemotherapy regimens with a HDAC inhibitor. HB patient derived xenograft (PDX) mice models were developed and treated based off the lowest viability of PDSp drug screen. Mice were started on study when tumor volume reached 0.1-0.4 cm3 and were sacked when tumors reached diameter of 1.5 cm or at the end of the 6-week study period. Tumors were sectioned and evaluated for Ki67% and necrosis. Results: HDAC RNA and protein expression was elevated in HB tumors compared to normal livers. Four unique HB PDX models, including high risk, relapse and treatment refractory cases, were developed and validated from treatment-refractory patient tumors. Panobinostat (IC50 of 0.013-0.059 mM) showed strong in vitro effects with the lowest cell viability compared to other HDAC inhibitors. PDSp demonstrated the highest level of cell death with combination treatment of vincristine/irinotecan/panobinostat (VIP). After 6 week of treatment[SV1] , all four models had a limited response to VI therapy; however, showed a much improved response with VIP. All four models responded to therapy with a decrease in tumor size compared to placebo and survival to 6 weeks. Two of our four models that had showed some initial response to VI therapy demonstrated necrotic cell death, lower Ki67%, decreased serum alpha fetoprotein (AFP) and reduced tumor burden compared to paired vincristine/irinotecan (VI) and placebo. Conclusions: Utilizing a preclinical pipeline for HB, we have shown that panobinostat in combination with VI chemotherapy can induce an effective tumor response in models developed from high risk, relapse, and treatment refractory HB patients. This clinically relevant methodology can be used to screen novel targeted combination therapies with the VI backbone in order to create novel treatment strategies for future clinical trials. Citation Format: Andres F Espinoza, Roma Patel, Sai Govindu, Pavan Kureti, Bryan Armbruster, Sarah Woodfield, Sanjeev A Vasudevan. A novel treatment strategy for high-risk and relapse/refractory hepatoblastoma [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr A003.

Selumetinib overcomes gefitinib primary and acquired resistance by regulating MIG6/STAT3 in NSCLC.

Gefitinib, as the first-generation epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI), has achieved great advances in the treatment of non-small cell lung cancer (NSCLC), but drug resistance will inevitably occur. Therefore, exploring the resistance mechanism of gefitinib and developing new combination treatment strategies are of great importance. In our study, the results showed that selumetinib (AZD6244) synergistically inhibited the proliferation of NSCLC with gefitinib. Selumetinib also enhanced gefitinib-induced apoptosis and migration inhibition ability in gefitinib-resistant lung cancer cell lines. Subsequently, the negative regulation between MIG6 and STAT3 was observed and verified through the STRING database and western blotting assays. Sustained activation of STAT3 was significantly downregulated when co-treatment with selumetinib in gefitinib-resistant cells. However, the downregulation of p-STAT3, resulting from the combination of selumetinib and gefitinib was counteracted by the deletion of MIG6, suggesting that selumetinib enhanced gefitinib sensitivity by regulating MIG6/STAT3 in NSCLC. In contrast, p-STAT3 was further inhibited after treatment with gefitinib and selumetinib when MIG6 was overexpressed. Furthermore, the combined administration of selumetinib and gefitinib effectively promoted the sensitivity of lung cancer xenografts to gefitinib in vivo, and the tumor inhibition rate reached 81.49%, while the tumor inhibition rate of the gefitinib monotherapy group was only 31.95%. Overall, MIG6/STAT3 negative regulation plays an important role in the sustained activation of STAT3 and the resistance to EGFR-TKIs. Our study also suggests that EGFR-TKIs combined with MEK1/2 inhibitors, such as selumetinib, may be beneficial to those NSCLC patients who develop a primary or acquired resistance to EGFR-TKIs, providing theoretical support for combining TKIs and selumetinib in clinical cancer treatment.