Photobiomodulation Enhances Cisplatin Cytotoxicity in a Culture Model with Oral Cell Lineages

Long-term survival of cancer patients after photobiomodulation therapy for prevention and treatment of oral mucositis

BACKGROUND

Photobiomodulation therapy (PBMT) has been employed for the prevention and treatment of oral mucositis in patients with head and neck cancer undergoing treatment. However, information about the survival of patients receiving PBMT is still lacking. Therefore, the aim of this study was to correlate the survival of patients who either received or did not receive PBMT, combined with cancer treatments, and to assess whether the number of PBMT sessions had a positive impact on survival.

METHODS

The records of 751 patients seen at Hospital de Caridade São Vicente de Paulo diagnosed with head and neck cancer, treated by D.L.P., the sole operator of PBMT, between 2000 and 2016, were analyzed. The median survival rates were compared by analyzing diagnostic staging, the combination of cancer treatments, and the number of PBMT sessions. Correlation analyses were performed to assess the interactions between the number of PBMT sessions and survival.

RESULTS

PBMT increased survival by 55.14%, from 1.07 (Without PBMT) to 1.66 years (With PBMT) for the total population and more significantly in Group 41 (stages III and IV, radiation therapy/chemotherapy, with more than five PBMT sessions), the median survival value of 1.83 years, which represents a 66.36% higher survival rate. In all the analyzed populations, the larger number of sessions was associated with better survival. In terms of survival, advanced stages III and IV almost equated with stages I and II in the absence of PBMT.

CONCLUSIONS

PBMT seems to interfere with the survival of patients with head and neck cancer, corroborating its recommendation for the treatment of mucositis, but further research is needed to investigate possible synergistic effects between PBMT and cancer treatments.

[Photobiomodulation and vulvovaginal disorders after anticancer treatments]

Anticancer treatments induce vulvovaginal complications that alter the quality of life and sexuality of patients. New technologies, such as photobiomodulation, could address this problem, for which few effective therapeutic solutions exist. The objective of this study was to describe the characteristics of patients seeking treatment and to observe the effects of photobiomodulation. This is a prospective cohort of patients treated for cancer, in failure of first-line medical treatment, managed at the University Hospital of Nîmes. The history, symptoms and impact of the disorders on their quality of life were collected. At follow-up, improvement was assessed using the PGI-I and FSFI questionnaires. Twenty-eight patients were treated. They were all menopausal, half of them after anticancer treatments [chemotherapy (78%), radiotherapy (36%), hormone therapy (36%)]. The main symptom reported was vaginal dryness (72%). Seventy-one percent of patients (n=20) felt that their daily life was affected≥8/10. All patients had sexual dysfunction. Twenty-two patients received at least 6 sessions of photobiomodulation. Seventy-two percent (n=18) of patients felt better or much better after treatment (PGI-I≤2). The median improvement estimated by the patients was 65% (Q1=50%; Q3=72.5%). There was also a significant clinical improvement. No serious adverse events were reported. Due to the small number of patients in a heterogeneous population with no control group, we cannot extrapolate our results. However, the objective was to assess the status of these pathologies and the contribution of photobiomodulation in patients who have failed first-line treatment; and these results are encouraging.

5-Methoxytryptophan Sensitizing Head and Neck Squamous Carcinoma Cell to Cisplatitn Through Inhibiting Signal Transducer and Activator of Transcription 3 (STAT3)

Head and neck squamous cell carcinoma (HNSCC) is a common cancer of the oral cavity. Cisplatin (CDDP) is the ideal chemo-radiotherapy used for several tumor types, but resistance to the drug has become a major obstacle in treating patients with HNSCC. 5-methoxytryptophan (5-MTP), a 5-methoxyindole metabolite of tryptophan metabolism, reduces inflammation-mediated proliferation and metastasis. This study aimed to assess the anti-oral cancer activity of 5-MTP when used alone or in combination with CDDP. Results showed that CDDP dose dependently reduced the growth of SSC25 cells but not 5-MTP. The combination of CDDP and 5-MTP exerted additional inhibitory effect on the growth of SSC25 cells by attenuating the phosphorylation of STAT3. In the 4-nitroquinoline-1-oxide-induced oral cancer mouse model, 5-MTP sensitized the reduction effect of CDDP on tumorigenesis, which restricted the tongue tissue in hyperkeratotic lesion rather than squamous cell carcinoma. The combination of CDDP and 5-MTP may be a potent therapeutic strategy for HNSCC patients with radiotherapy.

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.

Safety and efficacy of photobiomodulation therapy in oncology: A systematic review

We performed a systematic review of the current literature addressing the safety and efficacy of photobiomodulation therapy (PBMT) in cancer patients. In this systematic review, the Preferred Reporting Items for Systematic Reviews and Meta‐Analyses (PRISMA) guidelines were used. In vitro, in vivo, and clinical studies, which investigated the effect of PBMT on cell proliferation/differentiation, tumor growth, recurrence rate, and/or overall survival were included. The Medline/PubMed, EMBASE, and Scopus databases were searched through April 2020. A total of 67 studies met the inclusion criteria with 43 in vitro, 15 in vivo, and 9 clinical studies identified. In vitro studies investigating the effect of PBMT on a diverse range of cancer cell lines demonstrated conflicting results. This could be due to the differences in used parameters and the frequency of PBM applications. In vivo studies and clinical trials with a follow‐up period demonstrated that PBMT is safe with regards to tumor growth and patient advantage in the prevention and treatment of specific cancer therapy‐related complications. Current human studies, supported by most animal studies, show safety with PBMT using currently recommended clinical parameters, including in Head & Neck cancer (HNC) in the area of PBMT exposure. A significant and growing literature indicates that PBMT is safe and effective, and may even offer a benefit in patient overall survival. Nevertheless, continuing research is indicated to improve understanding and provide further elucidation of remaining questions regarding PBM use in oncology.

Effects of photobiomodulation on cellular viability and cancer stem cell phenotype in oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC) is the most common head and neck malignancy; it has been shown that cancer stem cells (CSC) are present in OSCC and associated with tumor growth, invasion, metastasis, and therapeutic resistance. Photobiomodulation (PBM) is an alternative tool for oncologic treatment adverse effects such as oral mucositis (OM); however, controversy exists regarding the undesirable effects of PBM on tumor or CSC. This study aimed to evaluate in vitro, the effects of PBM, with the same dosimetric parameters as those used in the clinic for OM prevention and treatment, on OSCC cellular viability, as well as PBM's effect on CSC properties and its phenotype. OSCC cell lines were submitted to single or daily PBM with 3 J/cm² and 6 J/cm² and then the cellular viability was evaluated by MTT, NRU (neutral red uptake), and CVS (crystal violet staining). The CSC populations were evaluated by clonogenic formation assay, flow cytometry, and RT-qPCR. The single PBM with the 3 J/cm² group was associated with increased cellular viability. Daily PBM with 3 J/cm² and 6 J/cm² was associated with a significant decrease in cellular viability. Additionally, daily PBM was not able to promote CSC self-renewal or the CD44^high/ESA^low and CD44^high/ESA^high cellular phenotypes. Moreover, a decrease in the number of spheres and in the expression of the CSC related gene BMI1 was observed after daily PBM with 6 J/cm². Daily PBM with 3 J/cm² and 6 J/cm² showed an inhibitory effect on cellular viability and was not able to promote the CSC self-renewal or phenotype.

Cisplatin influences the skin ion transport - An in vitro study

Platinum-based drugs, used in treating tumors, cause numerous undesirable effects in patients, like neuropathic pain, hypersensitivity, reddening, pruritus and rash. Changes in Na⁺ transport modify local osmolality and contribute to the initiation of hypersensitivity and allergy. They are also associated with stimulation of C-fibres and hyperalgesia. Cl^- transport is essential for regulation of sweat composition and the migration of immunocompetent cells. The aim of the conducted study was to assess the effect of a cisplatin solution on the electrophysiological parameters of the isolated rabbit skin specimens. The difference in transepithelial electrical potential (PD) and resistance (R) in stationary conditions and during 15 s mechanical-chemical stimulation (PDmin and PDmax), were measured. Measurement of R revealed that tissue samples were live, and their permeability to ions were stable. Control specimens had PD -0.22 mV (median). The PD of specimens treated by cisplatin was -0.55 mV (median), to for cisplatin and bumetanide 0 mV (median). Treatment with cisplatin did not change the continuous transport of Na⁺ and K⁺ ions, but did change that of Cl^- ions. Stimulation of samples with the transport blockers of Cl^-, Na⁺ and both induced repeatable and measurable reactions in the transport of the appropriate ions. It was shown that absorption of Na⁺ ions and release of Cl^- ions was intensified than in the untreated specimens. It was proven in the study that cisplatin influences the Na⁺ and Cl^- transport in the skin cells. Restoring the balance in ion flow can prevent side effects of use cisplatin-based drugs.