Caspase-3 activity predicts local recurrence in rectal cancer.

Purpose: Radiotherapy followed by total mesorectal excision surgery has been shown to significantly reduce local recurrence rates in rectal cancer patients. Radiotherapy, however, is associated with considerable morbidity. The present study evaluated the use of biochemical detection of enzymatic caspase-3 activity as preoperative marker for apoptosis to preselect patients that are unlikely to develop a local recurrence to spare these patients from overtreatment and the negative side effects of radiotherapy.

A systemic antitumor immune response prevents outgrowth of lung tumors after i.v. rechallenge but is not able to prevent growth of experimental liver tumors.

Although a systemic antitumor immune response by antibodies or T cells is often detected in cancer patients, this response mostly does not result in tumor rejection. The beneficial effect of tumor vaccination on survival rates is limited as tumor response is low. In contrast to solid tumors, circulating tumor cells may be more easily accessible and therefore destroyed by the immune system and thus prevent metastases.

Rat colon carcinoma cells that survived systemic immune surveillance are less sensitive to NK-cell mediated apoptosis.

In order to form distant metastases, cells from the primary tumor have to detach, enter the blood- or lymph-compartment and escape immune surveillance. Here, we describe the selection of rat colon carcinoma cell lines (CC531s-m1 and CC531s-m2) that escaped from systemic immune surveillance; CC531s cells were injected into the v. jugularis of Wag/Rij rats, after three weeks the lung tumors were isolated, the tumor cells were cultured, characterized and injected again.

Immunological aspects of photodynamic therapy of liver tumors in a rat model for colorectal cancer.

We have investigated tumor immunological effects of photodynamic therapy (PDT) of liver metastases. Livers of Wag/Rij rats were inoculated with three tumors of a syngeneic rat colon carcinoma cell line, CC531. One tumor in each rat was illuminated, with or without previous administration of the photosensitizer metatetrahydroxyphenylchlorin (mTHPC).

The immunological consequences of photodynamic treatment of cancer, a literature review.

In this review we discuss the effect of photodynamic treatment (PDT) of solid tumors on the immune response. The effect on both the innate and adapted immune response is discussed. We have summarized the evidence that PDT causes or enhances an anti-tumor response.

A tumor-specific kinase activity regulates the viral death protein Apoptin.

Apoptin, a chicken anemia virus-encoded protein, is thought to be activated by a general tumor-specific pathway, because it induces apoptosis in a large number of human tumor or transformed cells but not in their normal, healthy counterparts. Here, we show that Apoptin is phosphorylated robustly both in vitro and in vivo in tumor cells but negligibly in normal cells, and we map the site to threonine 108. A gain-of-function point mutation (T108E) conferred upon Apoptin the ability to accumulate in the nucleus and kill normal cells, implying that phosphorylation is a key regulator of the tumor-specific properties of Apoptin.