Laser photochemotherapy with anthracyclines on cultured human squamous carcinoma cells

The Rationale for "Laser-Induced Thermal Therapy (LITT) and Intratumoral Cisplatin" Approach for Cancer Treatment

Cisplatin is one of the most widely used anticancer drugs in the treatment of various types of solid human cancers, as well as germ cell tumors, sarcomas, and lymphomas. Strong evidence from research has demonstrated higher efficacy of a combination of cisplatin and derivatives, together with hyperthermia and light, in overcoming drug resistance and improving tumoricidal efficacy. It is well known that the antioncogenic potential of CDDP is markedly enhanced by hyperthermia compared to drug treatment alone. However, more recently, accelerators of high energy particles, such as synchrotrons, have been used to produce powerful and monochromatizable radiation to induce an Auger electron cascade in cis-platinum molecules. This is the concept that makes photoactivation of cis-platinum theoretically possible. Both heat and light increase cisplatin anticancer activity via multiple mechanisms, generating DNA lesions by interacting with purine bases in DNA followed by activation of several signal transduction pathways which finally lead to apoptosis. For the past twenty-seven years, our group has developed infrared photo-thermal activation of cisplatin for cancer treatment from bench to bedside. The future development of photoactivatable prodrugs of platinum-based agents injected intratumorally will increase selectivity, lower toxicity and increase efficacy of this important class of antitumor drugs, particularly when treating tumors accessible to laser-based fiber-optic devices, as in head and neck cancer. In this article, the mechanistic rationale of combined intratumor injections of cisplatin and laser-induced thermal therapy (CDDP-LITT) and the clinical application of such minimally invasive treatment for cancer are reviewed.

Photosensitizing and radiosensitizing effects of mitoxantrone: combined chemo-, photo-, and radiotherapy of DFW human melanoma cells

This study evaluated the effects of mitoxantrone (MX), an antitumor agent, as a sensitizer to both photodynamic and radiation therapy in DFW human melanoma cells. Cells were incubated with MX at different concentrations for 90 min and then exposed to non-coherent light at different fluence rates and/or X-ray ionizing radiation at different dose rates. Combinatorial effects of this chemo-, photo-, and radiotherapy were also evaluated. MX had no significant effects on viability at moderate doses but had a strong cytotoxic effect on cancer cells when used as a photosensitizer. MX also acted as a potent radiosensitizer. We observed a dose-dependent effect on cell viability in cells exposed to MX in combination with phototherapy and radiotherapy. Strong synergistic effects were observed for combinations of two or more treatment methods, which, in some cases, induced complete cell death. Thus, a combination of ionizing radiation with MX-mediated photodynamic therapy could serve as a new method for cancer therapy with fewer adverse side effects.

Evaluating the antitumor activity of combined photochemotherapy mediated by a meso-substituted tetracationic porphyrin and adriamycin

The combined anticancer modality comprising porphyrins as photodynamic sensitizers and anticancer drugs has been an interesting subject for many researchers. In this study, the photochemotherapeutic effect mediated by simultaneous photoactivation of tetracationic meso-tetrakis(N-methyl-4-pyridyl) porphine tetratosylate (TMPyP) and adriamycin (ADM) were explored using human hepatocellular carcinoma cell line (HePG2). The efficiency of TMPyP acting in concert with ADM in the dark and in the presence of photoirradiation was evaluated, by studying cell viability, caspase-3 activity and ultrastructural changes in the cells after incubation with each of the two agents, separately, or simultaneously as a co-mixture. Under dark conditions, the simultaneous incubation of cells with TMPyP and ADM significantly enhanced cell death by 1.8 folds and 1.3 folds, compared with TMPyP or ADM treatment, respectively. After photoirradiation, the antiproliferative effect of the co-treatment with TMPyP and ADM increased further by 2 folds. Transmission electron microscopy and the measurements of caspase-3 levels in treated cells revealed that the co-treatment of cells with ADM and TMPyP followed by light irradiation directed the cell death towards necrosis and abrogated the apoptotic cell death pathway, which was exhibited in cells treated with ADM in absence and in presence of photoirradiation.

Retention of intratumor injections of cisplatinum in murine tumors and the impact on laser thermal therapy for cancer treatment

Recent studies using murine models of human squamous cell carcinoma (SCCA) have revealed a significant improvement in survival and cure rate of animals transplanted with human SCCA when treated with a combination of intratumor injections of chemotherapy and laser induced thermal therapy (LITT). These preliminary results suggest that this novel combination therapy may lead to improved clinical response compared to either treatment modality alone. Using a murine model of human SCCA we investigated two different modes of intratumor injection of cisplatin: a sustained-release cisplatin gel implant (CDDP/gel) versus cisplatin in solution (CDDP) at varying doses (range 1-3 mg/ml). In addition, we tested CDDP/gel combined with LITT. Results showed optimal drug concentration (30-300 nM) at tumor margins up to 4 h after injection of CDDP/gel implant compared to 3 nM at 5 min after injection with CDDP solution. Combined CDDP/gel and laser therapy significantly decreased tumor volume (P<0.05), with recurrence in only 25% of animals tested, compared to 78% tumor regrowth after LITT alone. These results suggest that laser chemotherapy may be an effective treatment for head and neck SCCA.

Intratumor injections of cisplatin and laser thermal therapy for palliative treatment of recurrent cancer

OBJECTIVE

The aim of this work was to report initial findings on the clinical application of intratumor injection of cisplatin in a gel (CDDP/gel) combined with laser-induced thermal therapy (LITT) for cancer treatment in a single patient with advanced stage disease.

BACKGROUND DATA

LITT with the neodymium:yttriumaluminum- garnet (Nd:YAG) laser via fiberoptics is a precise, minimally invasive alternative for thermoablation of unresectable or recurrent head and neck neoplasms, but recurrence is often seen at the treatment margins. Combining intratumor chemotherapy with interstitial laser should be most effective using drugs with thermally enhanced toxicity, such as cisplatin. The CDDP/gel therapeutic implant was expected to retain a higher concentration of cisplatin in the tumor margins for improved LITT treatment of the patient presented.

METHODS

In this case report, the cisplatin dose was 0.25 mL gel/cm(3) tumor volume (20 mg of CDDP) followed by LITT (Nd:YAG laser, 50 W, PD = 2,200 J/cm(2)) after the chemotherapy session.

RESULTS

The patient responded with local tumor eradication, and no signs of systemic toxicity were observed related to this therapy. However, the patient developed progressive metastatic disease in the lungs and died 2.5 months later.

CONCLUSIONS

This is a report of a patient with an accessible solid tumor who was treated with intratumor injection of CDDP/gel followed by LITT, which proved to be feasible. Based on preclinical evidence obtained at UCLA and the results of this study, we are encouraged to continue our refinement of LITT combined with chemotherapy for cancer treatment.

Synthesis of tetrakis(multifluoro-4-pyridyl)porphin derivatives as acetylcholinesterase inhibitors

New tetrakis(multifluoro-4-pyridyl)porphin derivatives (2-4) and water soluble porphyrin (5) were synthesized to investigate their interactions with acetylcholinesterase from electric eel. These compounds have been found to be the potent reversible inhibitors of the enzyme with Ki values of microM range. In addition, porphyrin (5) showed broad spectrum of anticancer activities.

Improved photochemotherapy of malignant cells with daunomycin and the KTP laser

Laser photochemotherapy of malignancies may become an effective palliative treatment for advanced had and neck cancer using light-sensitive, chemotherapeutic drugs activated in tumors via interstitial laser fiberoptics. Previously, it was reported that cultured human P3 squamous cells incubated 2 hours with daunomycin (Dn) exhibited tenfold enhanced cytotoxicity after exposure to argon laser light at 514 nm. This short-term uptake leads to drug localization in cytoplasmic and membrane sites prior to nuclear accumulation and daunomycin topoisomerase inhibition. In the current study phototoxicity of Dn-sensitized human cancer cells was tested using broad-spectrum white light compared to monochromatic green-wavelength light. Drug uptake and laser energy levels were optimized for maximum synergy. To test light-enhanced chemotherapy in vitro, the kinetics of cell uptake and toxicity of daunomycin was measured at 1, 2, and 5 microg/ml in three human tumor cell lines: P3 squamous-cell carcinoma, M26 melanoma, and TE671 fibrosarcoma. After 2 hr Dn uptake, all cell lines were tested for phototherapy response by exposure to 300- to 900-nm visible light from a xenon lamp or monochromatic 532-nm green light from a KTP laser. When the KTP laser output was varied from 0 to 120 Joules in Dn-sensitized tumor cells, a linear phototherapy response was seen with energy as low as 12 J inducing drug phototoxicity. These results provide evidence that daunomycin cytotoxicity is enhanced when exposed to 532-nm laser illumination in the three tumor types tested and confirm that the response is related to both energy level and drug dose.

Anthrapyrazoles and interstitial laser phototherapy for experimental treatment of squamous cell carcinoma

Interstitial laser therapy (ILT) is an effective palliative treatment for advanced head and neck cancer, but recurrence often is seen at the margin. The objective of the current study was to test combined drug and laser therapy as an experimental approach for improved treatment of human squamous cell carcinoma (SCCA). Human SCCA tumor transplants were grown in nude mice and injected with the photosensitive anthrapyrazole CI-941 before ILT. Intralesional drug injections alone at levels ranging from 60 to 1200 microg/gm of tumor induced a growth delay at the higher doses, but recurrence was seen in all 35 tumors tested. SCCA tumor transplants injected with 240 microg/gm CI-941 followed after 4 hours by ILT with the KTP532 laser led to a complete response rate of 72% (21/29) compared with 45% (13/29) for ILT alone. Laser chemotherapy was a significant improvement compared with ILT when partial and complete responses were combined (P < 0.03). The results provide preclinical evidence that laser chemotherapy may become a useful minimally invasive treatment for advanced squamous cell carcinoma of the head and neck.

Laser chemotherapy of human carcinoma cells with three new anticancer drugs

A new experimental therapy for squamous carcinoma was tested by sensitizing human tumor cells with light-sensitive anticancer drugs followed by laser illumination at visible or infrared wavelengths. The anthrapyrazole DUP-941 and the isoquinoline derivative DUP-840 were compared with the dianthraquinone hypericin. P3 human squamous carcinoma cells were incubated for 2 h with the drugs at escalating doses ranging from 5 to 100 micrograms/ml, then exposed to visible green 532-nm or infrared 1064-nm light at 300 J output from a KTP/Nd:YAG laser. Tumor cell toxicity measured by in vitro MTT viability assays was minimal after DUP-840 uptake but was slightly enhanced by infrared laser emissions. By contrast, the strong tumoricidal effects seen after DUP-941 uptake were amplified over 10-fold by 532-nm light and up to 2-fold by 1064-nm light. Hypericin-sensitized tumor cells were killed after 532 nm irradiation even at the lowest drug dose but were not affected by 1064-nm illumination. The results suggest that laser chemotherapy with drugs sensitive to photothermal energy could become a useful new treatment modality for cancer.