The involvement of granulocytes in spontaneous regression of Walker 256 carcinoma

Tumor growth characteristics of the Walker 256 AR tumor, a regressive variant of the rat Walker 256 A tumor

“…Few reports on spontaneous regressions of the W256 tumor have mainly connected this phenomenon to the rat strain, such as SpragueDawley rats, Buffalo rats and Fischer rats (Schmid et al, 1966;Jaganjac et al, 2008). In the present study, high amounts of spontaneous tumor regressions were observed even in Wistar rats.…”

“…Nevertheless, spontaneous W256 tumor regression can occur. This phenomenon is poorly documented (Cavalcanti et al, 2003;Schanoski et al, 2004;Jensen and Muntzing 1970) and has been associated to the rat strain (Schmid et al, 1966;Jaganjac et al, 2008). We have recently reported the generation of a regressive W256 variant named AR (Schanoski et al, 2004).…”

Granulocytes as effective anticancer agent in experimental solid tumor models

“…The results showed that innate immunity based on the immune competent granulocytes may be the cause of the well known phenomenon of spontaneous regression of W256 carcinoma in Sprague Dawley rats (Jaganjac et al, 2008). In the same study we have also shown that distraction of granulocytes from the tumor by s.c. Sephadex injection greatly decreased the incidence of W256 regression.…”

“…In an earlier study using murine B16-F10 melanoma (Zivkovic et al, 2007), we have found that s.c. injection of Sephadex distracts the granulocytes from melanoma, allowing faster progression of the tumor, indicating that neutrophils may have an important role in the host defence against malignant cells in (Jaganjac et al, 2008). The results showed that innate immunity based on the immune competent granulocytes may be the cause of the well known phenomenon of spontaneous regression of W256 carcinoma in Sprague Dawley rats (Jaganjac et al, 2008).…”

“…Rats were intramuscularly injected in the right hind limb with 250 mL of RPMI medium containing 10 7 W256 tumor cells and additionally s.c. with 5 ml Sephadex (Sephadex G-150, Pharmacia Fine Chemicals, Sweden) on each side in the lower dorsal quadrant. Namely, Sephadex distracts functional granulocytes from the blood into the Sephadex papula thus abolishing spontaneous W256 tumor regression in Sprague Dawley rats (Jaganjac et al, 2008). The Sephadex was prepared as described elsewhere (Zivkovic et al, 2005a).…”