Photodynamic therapy for the hypercalcemic type of the small cell carcinoma of the ovary in a mouse xenograft model

Secure transplantation by tissue purging using photodynamic therapy to eradicate malignant cells

The field of photodynamic therapy (PDT) for treating various malignant neoplasms has been given researchers' attention due to its ability to be a selective and minimally invasive cancer therapy strategy. The possibility of tumor cell infection and hence high recurrence rates in cancer patients tends to restrict autologous transplantation. So, the photodynamic tissue purging process, which consists of selective photoinactivation of the malignant cells in the graft, is defined as a compromising strategy to purify contaminated tissues before transplantation. In this strategy, the direct malignant cells' death results from the reactive oxygen species (ROS) generation through the activation of a photosensitizer (PS) by light exposure in the presence of oxygen. Since new PS generations can effectively penetrate the tissue, PDT could be an ideal ex vivo tissue purging protocol that eradicates cancer cells derived from various malignancies. The challenge is that the applied pharmacologic ex vivo tissue purging should efficiently induce tumor cells with minor influence on normal tissue cells. This review aims to provide an overview of the current status of the most effective PDT strategies and PS development concerning their potential application in ex vivo purging before hematopoietic stem cell or ovarian tissue transplantation.

Temoporfin (Foscan®, 5,10,15,20-tetra(m-hydroxyphenyl)chlorin)--a second-generation photosensitizer

This review traces the development and study of the second-generation photosensitizer 5,10,15,20-tetra(m-hydroxyphenyl)chlorin through to its acceptance and clinical use in modern photodynamic (cancer) therapy. The literature has been covered up to early 2011.

Small cell carcinoma of the ovary of the hypercalcaemic type: an analysis of clinical and prognostic aspects of a rare disease on the basis of cases published in the literature

PURPOSE

Ovarian small cell carcinoma of the hypercalcaemic type is a very rare and highly aggressive malignant disease, mainly affecting young women. Due to the rarity of this tumour entity, prospective randomised trials are unlikely to be conducted, and the only retrospective analysis based on a large case series is from 1994. Since diagnostic and treatment modalities may have changed, we initiated this analysis.

METHODS

The aim of our study was to review and analyse cases published since 1975 to validate former findings and to gather more information about therapy options, diagnostic and prognostic factors. A systematic literature search of the PubMed/Medline database was performed assessing all articles until September 2010. All retrieved articles were evaluated and cross-checked for references on the topic. In total, 135 cases were included, selected from 62 case reports and smaller case studies.

RESULTS

Small cell carcinoma mostly affects women with a mean age of 23.4 years. They present with unspecific symptoms like abdominal pain or palpable mass, sometimes accompanied by an elevated calcium or CA-125 serum concentration. The tumour appears nearly almost unilaterally, mostly affecting the right ovary. Tumour stage is a clearly prognostic factor. Adjuvant chemotherapy consisting of etoposide, cisplatinum/carboplatinum or vinca alkaloids has shown improved survival, whereas radiotherapy has not.

CONCLUSIONS

In spite of limitations this analysis provides new insights especially with respect to therapeutic aspects. This review underlines the importance of case reports in rare tumour entities in order to answer open questions.

Protoporphyrin IX fluorescence photobleaching is a useful tool to predict the response of rat ovarian cancer following hexaminolevulinate photodynamic therapy

OBJECTIVE

Accurate dosimetry was shown to be critical to achieve effective photodynamic therapy (PDT). This study aimed to assess the reliability of in vivo protoporphyrin IX (PpIX) fluorescence photobleaching as a predictive tool of the hexaminolevulinate PDT (HAL-PDT) response in a rat model of advanced ovarian cancer.

MATERIALS AND METHODS

Intraperitoneal 10(6) NuTu 19 cells were injected in 26 female rats Fisher 344. Peritoneal carcinomatosis was obtained 26 days post-tumor induction. Four hours post-intraperitoneal HAL (Photocure ASA, Oslo, Norway) injection, a laparoscopic procedure (D-light AutoFluorescence system, Karl Storz endoscope, Tuttlingen, Germany) and a fluorescence examination were made for 22 rats. The first group (LASER group, n=26) was illuminated with laser light using a 532 nm KTP laser (Laser Quantum, Stockport, UK) on 1 cm(2) surface at 45 J/cm(2). The second group (NO LASER group, n=26) served as controls. Biopsies were taken 24 hours after PDT. Semi-quantitative histology was performed and necrosis value was determined: 0--no necrosis to 4--full necrosis. Fluorescence was monitored before and after illumination on complete responders (NV=3-4; n=20) and non-responders (NV=0-2; n=6).

RESULTS

High PpIX photobleaching corresponded with complete responders whereas low photobleaching corresponded with non-responders (P<0.05). A direct linear correlation was shown between photobleaching and necrosis (R(2)=0.89).

CONCLUSION

In vivo PpIX fluorescence photobleaching is useful to predict the tissue response to HAL-PDT.

Carcinome à petites cellules de l'ovaire hypercalcémiant révélé par un épisode de pancréatite aiguë : à propos d'un cas

Small cell carcinoma of the ovary of the hypercalcemic type is a rare tumour, usually lethal and occurring almost exclusively in young patients. In the majority of described cases, signs of this lesion were revealed by the associated hypercalcemia or by virtue of the physical tumour bulk alone. We report the first case of ovarian small cell carcinoma of the hypercalcemic revealed by a severe acute pancreatitis in a 19-year-old patient.

Effect of meta-tetra(hydroxyphenyl)chlorin (mTHPC)-mediated photodynamic therapy on sensitive and multidrug-resistant human breast cancer cells

Meta-tetra(hydroxyphenyl)chlorin (mTHPC) is in clinical trials for the photodynamic therapy (PDT) of localized-stage cancer. The PDT susceptibility of cells expressing multidrug resistance (MDR) phenotype is an attractive possibility to overcome the resistance to cytotoxic drugs observed during cancer chemotherapy. The accumulation, photocytotoxicity and intracellular localization of mTHPC were examined using the doxorubicin selected MCF-7/DXR human breast cancer cells, expressing P-glycoprotein (P-gp), and the wild-type parental cell line, MCF-7. No significant difference in mTHPC accumulation was observed between the two cell lines up to 3 h contact. The photodynamic activity of mTHPC, measured 24 h after irradiation with red laser light (lambda=650 nm), was significantly greater in MCF-7/DXR as compared to MCF-7 cells. A light dose of 2.5 J cm(-2) inducing 50% of cytotoxicity in MCF-7, resulted in 85% cytotoxicity in MCF-7/DXR. The presence of P-gp inhibitors SDZ-PSC-833 and cyclosporin A did not modify the mTHPC-induced cytotoxicity. The difference in intracellular mTHPC distribution pattern between two cell lines may contribute to different photocytotoxicity. Our results indicate that mTHPC mediated PDT could be useful in killing cells expressing MDR phenotype.

Effects of fluence rate on cell survival and photobleaching in meta-tetra-(hydroxyphenyl)chlorin-photosensitized Colo 26 multicell tumor spheroids

We report the influence of fluence rate on the photobleaching and cell survival in Colo 26 multicell spheroids photosensitized by meta-tetra-(hydroxyphenyl)chlorin (mTHPC). Photosensitizer degradation and therapeutic efficacy increased dramatically and progressively when the fluence rate was reduced over the range from 90 to 5 mW cm-2. These experimental results were compared to a mathematical model of photobleaching based on self-sensitized singlet oxygen reactions with the photosensitizer ground state. This model incorporates photophysical parameters obtained from microelectrode measurements of oxygen depletion at the surface of mTHPC-sensitized spheroids and was refined by including the inhomogeneous distribution of mTHPC in spheroids and oxygen depletion in the bulk medium. Since the model is consistent with the experimental data we conclude that the fluence rate dependence of the cell survival and of mTHPC photobleaching is due to photochemical oxygen consumption and a predominantly singlet oxygen-mediated mechanism of mTHPC photobleaching. The threshold dose of reacting singlet oxygen was calculated to be 7.9 +/- 2.2 mM in this system.