Combination Treatment Of Temozolomide Research Articles

CTIM-36. IMMUNOHISTOCHEMISTRY EVALUATION ON PRE-TREATMENT TUMOR TISSUE PREDICTS TREATMENT RESPONSE TO MN-166 (IBUDILAST) AND TEMOZOLOMIDE COMBINATION THERAPY IN GLIOBLASTOMA PATIENTS

Abstract STUDY DESIGN MN-166-GBM-1201 is a Phase I/II open-label clinical trial to evaluate MN166 (ibudilast) and temozolomide (TMZ) combination treatment in newly diagnosed and recurrent glioblastoma (GBM) patients. 62 GBM patients (34 newly diagnosed and 28 recurrent) were enrolled in the study. All patients received MN-166 and TMZ combination treatment until disease progression or withdrawal from the study for other reasons. METHODS Pre-treatment tumor tissue at initial surgery from 24 study participants was evaluated to determine potential predictors of response to MN-166, which has been shown to inhibit the interaction between macrophage migration inhibitory factor (MIF) and CD74 with ERK phosphorylation downstream of CD74. We looked at CD11b and CD3 expression to characterize the immune profile within the tumors and Ki67 to determine percentage of proliferating tumor cells, all of which were calculated by a masked researcher. Then, patients were stratified based on progression within the first five months after receiving MN-166 and TMZ. RESULTS Patients who did not progress within 5 months had a significantly lower percentage of CD3+ T cell infiltration than nonresponding patients (p = 0.045), and CD74 expression was lower in patients with no progression (p = 0.16). The other markers demonstrated no differences. MN-166 and TMZ combination therapy was generally safe and well tolerated. CONCLUSION CD3 expression was a good predictor for tumor progression for five months in recurrent GBM patients treated with MN-166 and TMZ. T cell infiltration within GBM tumors has been an active area of research with the success of immune checkpoint blockade (ICB) therapies in other cancers. Moreover, MN-166 has been shown to impact immune suppressive myeloid cells, which are linked to the immune suppressive tumor microenvironment and a resistance mechanism to ICB. Collectively, we postulate that the efficacy of MN-166 for treatment of GBM could be further enhanced by co-treatment with ICBs.

Targeted c-Myc Inhibition and Systemic Temozolomide Therapy Extend Survival in Glioblastoma Xenografts.

Glioblastoma is a highly aggressive disease with poor patient outcomes despite current treatment options, which consist of surgery, radiation, and chemotherapy. However, these strategies present challenges such as resistance development, damage to healthy tissue, and complications due to the blood-brain barrier. There is therefore a critical need for new treatment modalities that can selectively target tumor cells, minimize resistance development, and improve patient survival. Temozolomide is the current standard chemotherapeutic agent for glioblastoma, yet its use is hindered by drug resistance and severe side effects. Combination therapy using multiple drugs acting synergistically to kill cancer cells and with multiple targets can provide increased efficacy at lower drug concentrations and reduce side effects. In our previous work, we designed a therapeutic peptide (Bac-ELP1-H1) targeting the c-myc oncogene and demonstrated its ability to reduce tumor size, delay neurological deficits, and improve survival in a rat glioblastoma model. In this study, we expanded our research to the U87 glioblastoma cell line and investigated the efficacy of Bac-ELP1-H1/hyperthermia treatment, as well as the combination treatment of temozolomide and Bac-ELP1-H1, in suppressing tumor growth and extending survival in athymic mice. Our experiments revealed that the combination treatment of Bac-ELP1-H1 and temozolomide acted synergistically to enhance survival in mice and was more effective in reducing tumor progression than the single components. Additionally, our study demonstrated the effectiveness of hyperthermia in facilitating the accumulation of the Bac-ELP1-H1 protein at the tumor site. Our findings suggest that the combination of targeted c-myc inhibitory biopolymer with systemic temozolomide therapy may represent a promising alternative treatment option for glioblastoma patients.

Alterations of the Gut Microbiome in Recurrent Malignant Gliomas Patients Received Bevacizumab and Temozolomide Combination Treatment and Temozolomide Monotherapy.

The online version contains supplementary material available at 10.1007/s12088-021-00962-2.

PARP inhibition in UV-associated angiosarcoma preclinical models

PurposeAngiosarcoma (AS) is a rare vasoformative sarcoma, with poor overall survival and a high need for novel treatment options. Clinically, AS consists of different subtypes, including AS related to previous UV exposure (UV AS) which could indicate susceptibility to DNA damage repair inhibition. We, therefore, investigated the presence of biomarkers PARP1 (poly(ADP-ribose)polymerase-1) and Schlafen-11 (SLFN11) in UV AS. Based on experiences in other sarcomas, we examined (combination) treatment of PARP inhibitor (PARPi) olaparib and temozolomide (TMZ) in UV AS cell lines.MethodsPreviously collected UV AS (n = 47) and non-UV AS (n = 96) patient samples and two UV AS cell lines (MO-LAS and AS-M) were immunohistochemically assessed for PARP1 and SLFN11 expression. Both cell lines were treated with single agents PARPi olaparib and TMZ, and the combination treatment. Next, cell viability and treatment synergy were analyzed. In addition, effects on apoptosis and DNA damage were examined.ResultsIn 46/47 UV AS samples (98%), PARP1 expression was present. SLFN11 was expressed in 80% (37/46) of cases. Olaparib and TMZ combination treatment was synergistic in both cell lines, with significantly increased apoptosis compared to single agent treatment. Furthermore, a significant increase in DNA damage marker γH2AX was present in both cell lines after combination therapy.ConclusionWe showed combination treatment of olaparib with TMZ was synergistic in UV AS cell lines. Expression of PARP1 and SLFN11 was present in the majority of UV AS tumor samples. Together, these results suggest combination treatment of olaparib and TMZ is a potential novel AS subtype-specific treatment option for UV AS patients.

Successful Partnerships: Exploring the Potential of Immunogenic Signals Triggered by TMZ, CX-4945, and Combined Treatment in GL261 Glioblastoma Cells

Background: The relevance of the cancer immune cycle in therapy response implies that successful treatment may trigger the exposure or the release of immunogenic signals. Previous results with the preclinical GL261 glioblastoma (GB) showed that combination treatment of temozolomide (TMZ) + CX-4945 (protein kinase CK2 inhibitor) outperformed single treatments, provided an immune-friendly schedule was followed. Our purpose was to study possible immunogenic signals released in vitro by GB cells. Methods: GL261 GB cells were treated with TMZ and CX-4945 at different concentrations (25 µM–4 mM) and time frames (12–72 h). Cell viability was measured with Trypan Blue and propidium iodide. Calreticulin exposure was assessed with immunofluorescence, and ATP release was measured with bioluminescence. Results: TMZ showed cytostatic rather than cytotoxic effects, while CX-4945 showed remarkable cytotoxic effects already at low concentrations. Calreticulin exposure after 24 h was detected with TMZ treatment, as well as TMZ/CX-4945 low concentration combined treatment. ATP release was significantly higher with CX-4945, especially at high concentrations, as well as with TMZ/CX-4945. Conclusions: combined treatment may produce the simultaneous release of two potent immunogenic signals, which can explain the outperformance over single treatments in vivo. A word of caution may be raised since in vitro conditions are not able to mimic pharmacokinetics observed in vivo fully.

The interruption of atypical PKC signaling and Temozolomide combination therapy against glioblastoma

Current treatment options of glioblastoma include chemotherapy and limited surgical resection. Temozolomide (TMZ) is the current therapeutic choice for chemotherapy. Still, it has severe limitations due to the development of resistance that occurs by genetic modification and constitutive activation of several cell signaling pathways. Therefore, it is essential to develop combination therapy of TMZ with other novel compounds to prevent the development of chemo-resistance. In this study, we used two inhibitors; ICA, an inhibitor of PKC-ι and ζ-Stat, an inhibitor of PKC-ζ. T98G and U87MG glioblastoma cells were treated with either ICA or ζ-stat or TMZ monotherapies, as well as TMZ were combined with either ICA or ζ-stat for five consecutive days. Our in vitro results exhibited that ICA when combined with TMZ, significantly decreased the viability of cancerous cells compared with untreated or TMZ or ICA monotherapies. Additionally, glioblastoma cells were remarkably undergoing apoptosis against the combination treatment of TMZ and ICA nucleotide compared with untreated control cells, as suggested by our Annexin-V/PI flow cytometric analysis. Moreover, the combination of TMZ and ICA also decreased the invasion of glioblastoma cell lines by acting on FAK/Paxillin pathway, as evidenced by scratch assay, transwell invasion assay, Western blot and immunoprecipitation analysis. Furthermore, our in vivo data presented that the combination of ICA and TMZ also reduced glioblastoma tumor growth and volume in mice. These data suggest that atypical PKCs, particularly PKC-ι might be an important therapeutic target as adjuvant therapy in the treatment of glioblastoma.

Olaparib and temozolomide in desmoplastic small round cell tumors: a promising combination in vitro and in vivo

PurposeDesmoplastic small round cell tumors (DSRCTs) are highly malignant and very rare soft tissue sarcomas with a high unmet need for new therapeutic options. Therefore, we examined poly(ADP-ribose) polymerase 1 (PARP1) and Schlafen-11 (SLFN11) expression in DSRCT tumor tissue and the combination of PARP inhibitor olaparib with the alkylating agent temozolomide (TMZ) in a preclinical DSRCT model.MethodsPARP1 and SLFN11 have been described as predictive biomarkers for response to PARP inhibition. Expression of PARP1 and SLFN11 was assessed in 16 and 12 DSRCT tumor tissue samples, respectively. Effects of single-agent olaparib, and olaparib and TMZ combination treatment were examined using the preclinical JN-DSRCT-1 model. In vitro, single-agent and combination treatment effects on cell viability, the cell cycle, DNA damage and apoptosis were examined. Olaparib and TMZ combination treatment was also assessed in vivo.ResultsPARP1 and SLFN11 expression was observed in 100% and 92% of DSRCT tumor tissues, respectively. Olaparib treatment reduced cell viability and cell migration in a dose-dependent manner in vitro. Drug synergy between olaparib and TMZ was observed in vitro and in vivo. Combination treatment led to a cell-cycle arrest and induction of DNA damage and apoptosis, even when combined at low dosages.ConclusionWe show high PARP1 and SLFN11 expression in DSRCT tumor material and antitumor effects following olaparib and TMZ combination treatment in a preclinical DSRCT model. This suggests that olaparib and TMZ combination treatment could be a potential treatment option for DSRCTs.

SPDR-05 PARP INHIBITORS RESTORE TEMOZOLOMIDE SENSITIVITY IN MSH6-DEFICIENT TEMOZOLOMIDE-RESISTANT GLIOBLASTOMA CELLS

INTRODUCTIONMismatch repair (MMR) deficiency through MSH6 inactivation has been identified in approximately 25% of recurrent gliomas. This MMR deficiency represents a key molecular mechanism of acquired resistance to the alkylating chemotherapeutic agent temozolomide (TMZ). Potentiation of TMZ-induced cytotoxicity by PARP inhibitors (PARPi) has been reported in several cancers including gliomas. However, mechanisms that underlie the PARPi-mediated chemo-potentiation and biomarkers that predict benefit from this combination treatment have not been identified in gliomas. We investigated whether PARPis could restore TMZ sensitivity of MSH6-deficient chemoresistant gliomas and assessed the role of the base excision repair (BER) DNA damage repair pathway in PARPi-mediated effects.METHODSWe engineered glioblastoma cell lines and patient-derived glioblastoma neurosphere lines to knockdown MSH6 expression, resulting in acquired MMR-deficient resistance to TMZ. We treated these isogenic pairs of MSH6 wild type and MSH6-inactivated cells with TMZ, PARPi Veriparib or Olaparib, and combination. Using MSH6-deficient glioma xenografts, we tested the in vivo efficacy of veliparib in combination with TMZ. We used genetic and pharmacological approaches to assess the role of BER pathway in PARPi-mediated effects.RESULTSWe found that combination with PARPi restored TMZ sensitivity in MSH6-inactivated TMZ resistant cells whereas only subtle combination effects were seen in control MMR-proficient cells at the same PARPi concentrations. In vivo, combination treatment of TMZ with Veliparib demonstrated potent suppression of tumor growth of MSH6-inactivated orthotopic and flank xenografts, compared with TMZ monotherapy. Unlike PARPi, genetic and pharmacological blockage of BER pathway did not re-sensitize MSH6-inactivated cells to TMZ.CONCLUSIONPARPis restore TMZ sensitivity in MSH6-deficient glioblastoma cells. This combination treatment is a promising strategy to target acquired chemoresistance caused by MMR deficiency.

Momelotinib sensitizes glioblastoma cells to temozolomide by enhancement of autophagy via JAK2/STAT3 inhibition.

Temozolomide (TMZ) is a widely used chemotherapeutic agent for glioblastoma multiforme (GBM). However, chemoresistance to TMZ is still a major obstacle for GBM patients. An abundance of candidates has been reported to improve the chemotherapeutic sensitization of TMZ. In the present study, it was demonstrated that momelotinib (MTB) enhanced the sensitivity of glioma cells to TMZ in vitro, as evidenced by a noticeable decrease in cell growth and a significant increase in apoptosis and autophagy following treatment with the combination of TMZ and MTB compared to TMZ alone. Mechanistically, MTB and TMZ combination treatment reduced U251 cell growth by activating both apoptosis and autophagy pathways. MTB potentiated TMZ to inhibit the phosphorylation of JAK2 and STAT3 in U251 cells, resulting in the inactivation of JAK2/STAT3 signaling pathways. Moreover, we investigated the effect of MTB in xenograft tumor model mice. MTB and TMZ combination reduced tumor weight, decreased the expression of Ki‑67, P62, p‑STAT3 and p‑JAK2, while increased the ratio of LC3‑II/I and the expression of caspase‑3 and Beclin1 in vivo. Importantly, this combination was well tolerated, and caused significant tumor growth inhibition in the GBM xenografts. In summary, the present study provides pharmacological evidence that MTB has potential value in the treatment of GBM.

Abstract 5473: Anti-EGFR monoclonal antibody nimotuzumab enhances temozolomide-induced growth suppression of mutant EGFR expressing glioma xenografts.

Abstract A mutant form of EGFR, EGFRvIII or ΔEGFR, is common in glioblastoma (GBM) conferring enhanced tumorigenic activity as well as resistance to chemotherapeutic drugs. Nimotuzumab, a humanized monoclonal EGFR antibody, has been shown to exert a modest activity in patients with GBM, but its specific activity against ΔEGFR has not been fully investigated. We treated human glioma cells overexpressing either wild-type (wt) EGFR or ΔEGFR with nimotuzumab with or without temozolomide (TMZ). Nimotuzumab treatment resulted in reduction in tyrosine phosphorylation at C-terminal of ΔEGFR more preferentially than that of wtEGFR, albeit to a lesser extent than tyrosine kinase inhibitor AG1478. Nimotuzumab-induced EGFR tyrosine dephosphorylation was associated with a decrease in AKT phosphorylation, suggesting suppression of downstream signaling pathways. In animal models, growth of subcutaneous xenografts was suppressed by TMZ, but was not affected by nimotuzumab monotreatment. However, antitumor activity was synergistically enhanced when TMZ was combined with nimotuzumab in both U87MG.ΔEGFR and LNZ308.ΔEGFR xenografts, while such an effect was limited in wtEGFR-overexpressing xenografts. Similarly, compared with nimotuzumab or TMZ monotherapy, the combination treatment of TMZ with nimotuzumab significantly elongated survival of mice bearing intracerebral xenografts derived from U87MG.ΔEGFR (p < 0.001, logrank test), and U87MG.wtEGFR to a lesser extent (p = 0.006). These anti-tumor effects by the combination treatment were associated with a decreased proliferation rate and an increase in apoptosis rate in treated xenografts. The U87MG.ΔEGFR intracerebral tumors which had re-grown after the combination treatment with TMZ and nimotuzumab (“escapers”) exhibited an increase expression of MGMT as well as a decrease in mismatch repair (MMR) proteins, MSH6 and MLH1. The reduction of MMR expression was further retained in subcultured escaper cells. These expression changes were not observed in xenografts treated with any of vehicles or monotherapies. These results suggest that nimotuzumab has antitumor activity against mutant EGFR-expressing glioma in vivo when combined with TMZ, and the resistance to this combination treatment might involve expression change of both MGMT and MMR. Citation Format: Motoo Nagane, Yusuke Nitta, Saki Shimizu, Yukiko Shishido-Hara, Yoshiaki Shiokawa. Anti-EGFR monoclonal antibody nimotuzumab enhances temozolomide-induced growth suppression of mutant EGFR expressing glioma xenografts. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 5473. doi:10.1158/1538-7445.AM2013-5473 Note: This abstract was not presented at the AACR Annual Meeting 2013 because the presenter was unable to attend.

Modulation of KCa channels increases anticancer drug delivery to brain tumors and prolongs survival in xenograft model

Most anticancer drugs fail to impact patient survival since they fail to cross the blood-brain tumor barrier (BTB) at therapeutic levels. For example, Temozolomide (TMZ) exhibits some anti-tumor activity against brain tumors, so does Trastuzumab (Herceptin, Her-2 inhibitor), which might be effective against Her2 neu overexpressing gliomas. Nevertheless, intact BTB and active efflux system may prevent their entry to brain tumors. Previously we have shown that potassium channel agonists increased carboplatin and Her-2 neu antibody delivery in animal glioma models. Here, we studied whether potassium channel agonist increase TMZ and Herceptin delivery across the BTB to elicit anti-tumor activity and increase survival in nude mice with human glial tumor. The KCa channel activity and expression was also evaluated in human glioma tissues. We administered NS-1619, calcium-dependent potassium (KCa) channel agonist, with [14C]-TMZ, and quantified TMZ delivery. The results clearly demonstrate that when given systemically both TMZ and Herceptin do not cross the BTB in significant amounts, however, NS-1619 co-infusion with [14C]-TMZ and Herceptin resulted in enhanced drug delivery to brain-tumor cells. The combination treatment of TMZ and Herceptin also showed improved anti-tumor effect which was more prominent than that of either treatment alone in increasing the survival in mice with brain tumor, when co-infused with KCa channel agonists. In conclusion, KCa channel agonists may benefit brain tumor patients by increasing anti-neoplastic agent’s delivery to brain tumors. A clinical outcome of this research is the discovery of a novel drug delivery system that circumvents the BBB/BTB to benefit brain tumor patients.

Combination celecoxib and temozolomide in C6 rat glioma orthotopic model

The purpose of this study was to determine whether a combination treatment of temozolomide with celecoxib is effective in the rat orthotopic glioma model. After stereotactic injection of C6/LacZ rat glioma cells into the Sprague Dawley rat brain, the rats were randomly assigned to four treatment groups [group 1, control treatment; group 2, celecoxib (25 mg/kg p.o. everyday) alone; group 3, temozolomide (7.5 mg/kg i.p. for 5 days at 2nd week) alone; group 4, a combination of celecoxib and temozolomide]. Rats were sacrificed 18 days after treatment, and the body weight, tumor volume, tumor cell proliferation, microvessel densities, and apoptosis were evaluated. There was a significant reduction of tumor volume in combination group compared to control or single-agent therapy. The median tumor volume was estimated to be 111.5 mm(3) (control), 65.0 mm(3) (celecoxib), 71.8 mm(3) (temozolomide) and 18.7 mm(3) (combination). In the combination group, there was increased tumor cell apoptosis as well as decreased microvessel density and tumor cell proliferation relative to the control and single-agent therapy (P<0.05). Collectively, the data suggest that the combination celecoxib and temozolomide may provide a novel and effective approach to the treatment of glioblastoma.