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Metabolic interrogation as a tool to optimize chemotherapeutic regimens

View Article: PubMed Central - PubMed

ABSTRACT

Platinum-based (Pt) chemotherapy is broadly utilized in the treatment of cancer. Development of more effective, personalized treatment strategies require identification of novel biomarkers of treatment response. Since Pt compounds are inactivated through cellular metabolic activity, we hypothesized that metabolic interrogation can predict the effectiveness of Pt chemotherapy in a pre-clinical model of head and neck squamous cell carcinoma (HNSCC).

We tested the effects of cisplatin (CDDP) and carboplatin (CBP) on DNA damage, activation of cellular death cascades and tumor cell metabolism, specifically lactate production. Pt compounds induced an acute dose-dependent, transient drop in lactate generation in vitro, which correlated with effects on DNA damage and cell death. Neutralization of free radical stress abrogated these effects. The magnitude of this effect on lactate production correlated with the differential sensitivity of HNSCC cells to Pt compounds (CDDP vs CBP) and p53-driven Pt chemotherapy resistance. Using dual flank xenograft tumors, we demonstrated that Pt-driven effects on lactate levels correlate with effects on tumor growth delay in a dose-dependent manner and that lactate levels can define the temporal profile of Pt chemotherapy-induced metabolic stress. Lactate interrogation also predicted doxorubicin effects on cell death in both solid tumor (HNSCC) and acute myelogenous leukemia (AML) cell lines.

Real-time metabolic interrogation of acute changes in cell and tumor lactate levels reflects chemotherapy effects on DNA damage, cell death and tumor growth delay. We have identified a real-time biomarker of chemotherapy effectiveness which can be used to develop adaptive, iterative and personalized treatment regimens against a variety of solid and hematopoietic malignancies.

No MeSH data available.


Related in: MedlinePlus

Cisplatin triggers a rapid, concentration dependent decrease in cellular lactate productionA. Model of the hypothesized effects of CDDP on lactate production. The chloride (Cl) moieties are replaced upon exposure to glutathione (GSH), inactivating CDDP. Regeneration of GSH utilizes secondary reducing equivalents (NAD(P)H) and decreases the conversion of pyruvate into lactate. B. CDDP induced a concentration-dependent decrease in cellular lactate levels at 1hr following drug exposure. HN30 cells demonstrated approximately 25% greater decrease in lactate levels compared to their mutant TP53 counterpart, HN31, at each concentration. C. HN30 were exposed to CDDP [1μM] in the presence or absence of N-acetyl cysteine (NAC) [1-5mM]. Lactate levels were measured at 1hr following drug exposure. * indicates p-value < 0.05 compared to corresponding control condition. All values were normalized to corresponding control condition. Each experiment was carried out at least in triplicate, with values indicating means and error bars representing standard deviation.
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Figure 2: Cisplatin triggers a rapid, concentration dependent decrease in cellular lactate productionA. Model of the hypothesized effects of CDDP on lactate production. The chloride (Cl) moieties are replaced upon exposure to glutathione (GSH), inactivating CDDP. Regeneration of GSH utilizes secondary reducing equivalents (NAD(P)H) and decreases the conversion of pyruvate into lactate. B. CDDP induced a concentration-dependent decrease in cellular lactate levels at 1hr following drug exposure. HN30 cells demonstrated approximately 25% greater decrease in lactate levels compared to their mutant TP53 counterpart, HN31, at each concentration. C. HN30 were exposed to CDDP [1μM] in the presence or absence of N-acetyl cysteine (NAC) [1-5mM]. Lactate levels were measured at 1hr following drug exposure. * indicates p-value < 0.05 compared to corresponding control condition. All values were normalized to corresponding control condition. Each experiment was carried out at least in triplicate, with values indicating means and error bars representing standard deviation.

Mentions: CDDP can be inactivated by primary reducing equivalents (i.e. glutathione) which are regenerated via utilization of secondary reducing equivalents [21, 23, 24, 26]. As previously shown by our group using radiation-induced free radical stress, acute perturbations in levels of reducing equivalents can be reflected in an altered rate of pyruvate to lactate conversion (Figure 2A) [27, 28]. Exposure to CDDP triggered a rapid (1hr), concentration-dependent decrease in cellular lactate levels (Figure 2B). Treatment with CDDP is associated with approximately 25% more pronounced decrease in HN30 cellular lactate levels as compared to HN31. This difference is consistent with the greater sensitivity of HN30 to CDDP compared to HN31 measured using both MTT assay (GI50 HN30-1.94μM, HN31- 2.99μM) and clonogenic survival assay (Supplementary Figure 1). The addition of the ROS scavenger NAC reversed the decrease in lactate levels triggered by CDDP exposure in a dose-dependent fashion, consistent with a ROS-mediated mechanism (Figure 2C). NAC reversal of CDDP-induced lactate changes correlated with NAC reversal of CDDP toxicity as measured using clonogenic assays survival (Supplementary Figure 1). This is indicative of a shared ROS-mediated mechanism for both effects.


Metabolic interrogation as a tool to optimize chemotherapeutic regimens
Cisplatin triggers a rapid, concentration dependent decrease in cellular lactate productionA. Model of the hypothesized effects of CDDP on lactate production. The chloride (Cl) moieties are replaced upon exposure to glutathione (GSH), inactivating CDDP. Regeneration of GSH utilizes secondary reducing equivalents (NAD(P)H) and decreases the conversion of pyruvate into lactate. B. CDDP induced a concentration-dependent decrease in cellular lactate levels at 1hr following drug exposure. HN30 cells demonstrated approximately 25% greater decrease in lactate levels compared to their mutant TP53 counterpart, HN31, at each concentration. C. HN30 were exposed to CDDP [1μM] in the presence or absence of N-acetyl cysteine (NAC) [1-5mM]. Lactate levels were measured at 1hr following drug exposure. * indicates p-value < 0.05 compared to corresponding control condition. All values were normalized to corresponding control condition. Each experiment was carried out at least in triplicate, with values indicating means and error bars representing standard deviation.
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Figure 2: Cisplatin triggers a rapid, concentration dependent decrease in cellular lactate productionA. Model of the hypothesized effects of CDDP on lactate production. The chloride (Cl) moieties are replaced upon exposure to glutathione (GSH), inactivating CDDP. Regeneration of GSH utilizes secondary reducing equivalents (NAD(P)H) and decreases the conversion of pyruvate into lactate. B. CDDP induced a concentration-dependent decrease in cellular lactate levels at 1hr following drug exposure. HN30 cells demonstrated approximately 25% greater decrease in lactate levels compared to their mutant TP53 counterpart, HN31, at each concentration. C. HN30 were exposed to CDDP [1μM] in the presence or absence of N-acetyl cysteine (NAC) [1-5mM]. Lactate levels were measured at 1hr following drug exposure. * indicates p-value < 0.05 compared to corresponding control condition. All values were normalized to corresponding control condition. Each experiment was carried out at least in triplicate, with values indicating means and error bars representing standard deviation.
Mentions: CDDP can be inactivated by primary reducing equivalents (i.e. glutathione) which are regenerated via utilization of secondary reducing equivalents [21, 23, 24, 26]. As previously shown by our group using radiation-induced free radical stress, acute perturbations in levels of reducing equivalents can be reflected in an altered rate of pyruvate to lactate conversion (Figure 2A) [27, 28]. Exposure to CDDP triggered a rapid (1hr), concentration-dependent decrease in cellular lactate levels (Figure 2B). Treatment with CDDP is associated with approximately 25% more pronounced decrease in HN30 cellular lactate levels as compared to HN31. This difference is consistent with the greater sensitivity of HN30 to CDDP compared to HN31 measured using both MTT assay (GI50 HN30-1.94μM, HN31- 2.99μM) and clonogenic survival assay (Supplementary Figure 1). The addition of the ROS scavenger NAC reversed the decrease in lactate levels triggered by CDDP exposure in a dose-dependent fashion, consistent with a ROS-mediated mechanism (Figure 2C). NAC reversal of CDDP-induced lactate changes correlated with NAC reversal of CDDP toxicity as measured using clonogenic assays survival (Supplementary Figure 1). This is indicative of a shared ROS-mediated mechanism for both effects.

View Article: PubMed Central - PubMed

ABSTRACT

Platinum-based (Pt) chemotherapy is broadly utilized in the treatment of cancer. Development of more effective, personalized treatment strategies require identification of novel biomarkers of treatment response. Since Pt compounds are inactivated through cellular metabolic activity, we hypothesized that metabolic interrogation can predict the effectiveness of Pt chemotherapy in a pre-clinical model of head and neck squamous cell carcinoma (HNSCC).

We tested the effects of cisplatin (CDDP) and carboplatin (CBP) on DNA damage, activation of cellular death cascades and tumor cell metabolism, specifically lactate production. Pt compounds induced an acute dose-dependent, transient drop in lactate generation in vitro, which correlated with effects on DNA damage and cell death. Neutralization of free radical stress abrogated these effects. The magnitude of this effect on lactate production correlated with the differential sensitivity of HNSCC cells to Pt compounds (CDDP vs CBP) and p53-driven Pt chemotherapy resistance. Using dual flank xenograft tumors, we demonstrated that Pt-driven effects on lactate levels correlate with effects on tumor growth delay in a dose-dependent manner and that lactate levels can define the temporal profile of Pt chemotherapy-induced metabolic stress. Lactate interrogation also predicted doxorubicin effects on cell death in both solid tumor (HNSCC) and acute myelogenous leukemia (AML) cell lines.

Real-time metabolic interrogation of acute changes in cell and tumor lactate levels reflects chemotherapy effects on DNA damage, cell death and tumor growth delay. We have identified a real-time biomarker of chemotherapy effectiveness which can be used to develop adaptive, iterative and personalized treatment regimens against a variety of solid and hematopoietic malignancies.

No MeSH data available.


Related in: MedlinePlus