Weekly epirubicin plus lonidamine in advanced breast carcinoma

The Potential of Lonidamine in Combination with Chemotherapy and Physical Therapy in Cancer Treatment

Simple Summary

The unique characteristics of tumor energy metabolism (highly dependent on aerobic glycolysis, namely, the Warburg effect) make it an interesting and attractive target for drug discovery. Radio- and chemoresistance are closely associated with the Warburg effect. Lonidamine (LND), as a glycolytic inhibitor, although having low anticancer activity when used alone, exhibits selectivity to various tumors, and its adverse effects do not overlap when combined with other chemotherapeutic drugs. Therefore, LND may be very promising as a sensitizer of tumors to chemotherapeutic agents and physical therapies. This review summarizes the advance of LND in combination with chemotherapy and physical therapy over the past several decades, as well as the promising LND derivative adjudin (ADD). The underlying sensitizing mechanisms were also analyzed and discussed, which may contribute to an improved therapeutic effect in future clinical cancer treatment.

Abstract

Lonidamine (LND) has the ability to resist spermatogenesis and was first used as an anti-spermatogenic agent. Later, it was found that LND has a degree of anticancer activity. Currently, LND is known to target energy metabolism, mainly involving the inhibition of monocarboxylate transporter (MCT), mitochondrial pyruvate carrier (MPC), respiratory chain complex I/II, mitochondrial permeability transition (PT) pore, and hexokinase II (HK-II). However, phase II clinical studies showed that LND alone had a weak therapeutic effect, and the effect was short and reversible. Interestingly, LND does not have the common side effects of traditional chemotherapeutic drugs, such as alopecia and myelosuppression. In addition, LND has selective activity toward various tumors, and its toxic and side effects do not overlap when combined with other chemotherapeutic drugs. Therefore, LND is commonly used as a chemosensitizer to enhance the antitumor effects of chemotherapeutic drugs based on its disruption of energy metabolism relating to chemo- or radioresistance. In this review, we summarized the combination treatments of LND with several typical chemotherapeutic drugs and several common physical therapies, such as radiotherapy (RT), hyperthermia (HT), and photodynamic therapy (PDT), and discussed the underlying mechanisms of action. Meanwhile, the development of novel formulations of LND in recent years and the research progress of LND derivative adjudin (ADD) as an anticancer drug were also discussed.

Phase II trial of non-pegylated liposomal doxorubicin and low-dose prednisone in second-line chemotherapy for hormone-refractory prostate cancer

Aims and background

Non-pegylated liposomal doxorubicin (NPLD) (Myocet) has shown marked in vitro activity in castration-resistant prostate cancer (CRPC) and also in docetaxel-resistant cells, higher than that shown by pegylated liposomal doxorubicin. Its activity would seem to be due to a high intracellular drug concentration and induction of Golgi-dependent apoptosis. On the basis of these results, a clinical study was designed to assess the activity of NPLD and low-dose prednisone in second-line therapy.

Methods

Fifty-four patients were enrolled and evaluated. Eligibility criteria were histologically confirmed CRPC, PSA >20 ng/mL or measurable lesions according to the RECIST criteria, previous docetaxel-based chemotherapy, and adequate cardiac function. Patients were treated with weekly intravenous NPLD 25 mg/m2 and daily prednisone 10 mg until progression.

Results

Median patient age was 69 years (range, 52–83) and median baseline PSA concentration was 120 ng/mL (range, 5.35–4350). Sixteen (29.6%) patients had measurable lesions. Objective or PSA responses (>50% reduction) were observed in 8 (14.8%) patients. The median time to progression was 2.8 months and the median overall survival was 11.3 months. Toxicity was generally mild (grade 1–2) and infrequent, with grade 3–4 neutropenia in 12.9% of cases. Grade 3 nonhematological toxicities included nausea in 2 patients (3.7%) and fatigue and stomatitis in 1 case (1.9%). No drug-related serious adverse events were reported.

Conclusions

Weekly administration of NPLD is a well tolerated treatment with proven albeit limited activity.

Mechanism of antineoplastic activity of lonidamine

Lonidamine (LND) was initially introduced as an antispermatogenic agent. It was later found to have anticancer activity sensitizing tumors to chemo-, radio-, and photodynamic-therapy and hyperthermia. Although the mechanism of action remained unclear, LND treatment has been known to target metabolic pathways in cancer cells. It has been reported to alter the bioenergetics of tumor cells by inhibiting glycolysis and mitochondrial respiration, while indirect evidence suggested that it also inhibited l-lactic acid efflux from cells mediated by members of the proton-linked monocarboxylate transporter (MCT) family and also pyruvate uptake into the mitochondria by the mitochondrial pyruvate carrier (MPC). Recent studies have demonstrated that LND potently inhibits MPC activity in isolated rat liver mitochondria (K_i 2.5μM) and cooperatively inhibits l-lactate transport by MCT1, MCT2 and MCT4 expressed in Xenopus laevis oocytes with K_0.5 and Hill coefficient values of 36-40μM and 1.65-1.85, respectively. In rat heart mitochondria LND inhibited the MPC with similar potency and uncoupled oxidation of pyruvate was inhibited more effectively (IC₅₀~7μM) than other substrates including glutamate (IC₅₀~20μM). LND inhibits the succinate-ubiquinone reductase activity of respiratory Complex II without fully blocking succinate dehydrogenase activity. LND also induces cellular reactive oxygen species through Complex II and has been reported to promote cell death by suppression of the pentose phosphate pathway, which resulted in inhibition of NADPH and glutathione generation. We conclude that MPC inhibition is the most sensitive anti-tumour target for LND, with additional inhibitory effects on MCT-mediated l-lactic acid efflux, Complex II and glutamine/glutamate oxidation.

Reviving Lonidamine and 6-Diazo-5-oxo-L-norleucine to Be Used in Combination for Metabolic Cancer Therapy

Abnormal metabolism is another cancer hallmark. The two most characterized altered metabolic pathways are high rates of glycolysis and glutaminolysis, which are natural targets for cancer therapy. Currently, a number of newer compounds to block glycolysis and glutaminolysis are being developed; nevertheless, lonidamine and 6-diazo-5-oxo-L-norleucine (DON) are two old drugs well characterized as inhibitors of glycolysis and glutaminolysis, respectively, whose clinical development was abandoned years ago when the importance of cancer metabolism was not fully appreciated and clinical trial methodology was less developed. In this review, a PubMed search using the words lonidamine and 6-diazo-5-oxo-L-norleucine (DON) was undertaken to analyse existing information on the preclinical and clinical studies of these drugs for cancer treatment. Data show that they exhibit antitumor effects; besides there is also the suggestion that they are synergistic. We conclude that lonidamine and DON are safe and potentially effective drugs that need to be reevaluated in combination as metabolic therapy of cancer.

Troponin-T and myoglobin plus echocardiographic evaluation for monitoring early cardiotoxicity of weekly epirubicin–paclitaxel in metastatic breast cancer patients

Increased serum level of troponin-T and myoglobin has been recently reported to be related to cumulative anthracycline exposure. Left ventricular ejection fraction seems accurate in monitoring systolic function according to the latest version of Toxicity Criteria by chemotherapeutics 3.0. From January 2002, 20 patients with untreated advanced breast cancer received epirubicin (25 mg/m/week) and paclitaxel (80 mg/m/week) for 24 weeks. Troponin-T, myoglobin and biochemical serum enzymes circulating levels were measured immediately before and 4 h after epirubicin administration every week. Patients underwent electrocardiography and echocardiography at weeks 0, 8, 16 and 24. The number of courses administered was 352 (median 18, range 4-24). Epirubicin median dose administered was 600 mg/m and paclitaxel median dose administered was 1760 mg/m. Troponin-T never overcame the upper normal limit; one patient experienced troponin-T elevation without any clinical or instrumental sign of cardiac failure. Myoglobin never significantly increased with the exception of a patient who underwent several abdominal fluid drainages. Creatine kinase MB and C-reactive protein never moved outside the upper normal limit. No symptomatic cardiac event was recorded. In 55 performed echocardiograms at weeks 0, 8, 16 and 24, neither left ventricular ejection fraction nor early peak flow/atrial flow velocity registered any significant decrease. No troponin-T or myoglobin serum elevations and Left ventricular ejection fraction/early peak flow/atrial flow velocity changes were registered in our series of nonsymptomatic women during epirubicin/paclitaxel weekly chemotherapy in the absence of clinical cardiac toxicity. Longer follow-up is needed, however, to understand whether the troponin-T or myoglobin circulating level measurement is able to detect subclinical, early-stage doxorubicin-induced cardiotoxicity.

Lonidamine causes inhibition of angiogenesis-related endothelial cell functions

The aim of this study was to assess whether lonidamine (LND) interferes with some steps in angiogenesis progression. We report here, for the first time, that LND inhibited angiogenic-related endothelial cell functions in a dose-dependent manner (1-50 microg/ml). In particular, LND decreased proliferation, migration, invasion, and morphogenesis on matrigel of different endothelial cell lines. Zymographic and Western blot analysis assays showed that LND treatment produced a reduction in the secretion of matrix metalloproteinase-2 and metalloproteinase-9 by endothelial cells. Vessel formation in a matrigel plug was also reduced by LND. The viability, migration, invasion, and matrix metalloproteinase production of different tumor cell lines were not affected by low doses of LND (1-10 microg/ml), whereas 50 microg/ml LND, which corresponds to the dose used in clinical management of tumors, triggered apoptosis both in endothelial and tumor cells. Together, these data demonstrate that LND is a compound that interferes with endothelial cell functions, both at low and high doses. Thus, the effect of LND on endothelial cell functions, previously undescribed, may be a significant contributor to the antitumor effect of LND observed for clinical management of solid tumors.

Combination regimen of epirubicin, vinorelbine and 5-fluorouracil continuous infusion as first-line chemotherapy in anthracycline-naïve metastatic breast cancer patients

We investigated the activity and toxicity of a combination of vinorelbine 25 mg/m2 on days 1 and 15; epirubicin 25 mg/m2 on days 1, 8, 15; and 5-fluorouracil continuous infusion at 200 mg/m2 every day, administered as first-line chemotherapy in anthracycline-naive metastatic breast cancer patients. Fifty-three patients entered the study. Cycles were repeated every 28 days. Objective response was 60% by World Health Organisation (WHO) criteria and 63% by Response Evaluation Criteria in Solid Tumours (RECIST). The median time to progression was 12.7 months (17.6 months in responders) and the median survival duration was 32.9 months. The dose-limiting toxicity was leucopenia (grade 3/4 in 36% of patients). Grade 3/4 non-haematological toxicities included mucositis in 11% of patients, skin and cardiac toxicity in 4% and 2%, respectively. The combination of vinorelbine, epirubicin and 5-fluorouracil continuous infusion was found to be an active and manageable first-line regimen for metastatic breast cancer patients.