Abstract
Background: Neuroblastoma undergoes spontaneous regression frequently during its natural course. Although programmed cell death (PCD) has been implicated in this process, accumulating evidence suggests that apoptosis, a form of PCD that is regulated by caspases, may not play a major role. We examined the mechanism(s) of spontaneous regression of neuroblastoma, focusing on the role of Ras, a favorable prognostic marker of neuroblastoma. Methods: Tumor tissues were analyzed by light microscopy, electron microscopy, and immunohistochemistry to examine cell degeneration and expression of Ras and several indicators of PCD. Cell degeneration was also studied in vitro in neuroblastoma cells transfected with the H-ras gene. All statistical tests were two-sided. Results: Immunohistochemical analyses revealed that Ras expression was increased in areas of cellular degeneration lacking apoptotic characteristics. The degenerating cells were fragmented without nuclear condensation and, essentially, lacked caspase-3 activation and apoptotic DNA fragmentation. These cells had ultrastructural features of autophagic degeneration, another form of PCD that is distinct from apoptosis. Focal areas of degeneration associated with Ras expression were seen more frequently in tumors from patients detected in a mass-screening program (53 [60.9%] of 87) than in tumors from clinically detected, advanced-stage patients over 1 year of age (7[29.2%] of 24) (P=.006; chi-square test), suggesting a positive relationship between Ras-associated degeneration and probability of spontaneous regression/favorable prognosis. The characteristic features of Ras-associated nonapoptotic degeneration observed in tumor samples were recapitulated in vitro by transfection-mediated Ras expression, and Ras-mediated degeneration was augmented by TrkA, another favorable prognostic marker. Conclusions: High-level expression of H-Ras in neuroblastoma cells is associated with caspase cascade-independent, nonapoptotic PCD. This Ras-mediated nonapoptotic tumor cell death may play a key role in spontaneous regression of neuroblastoma.
| Original language | English |
|---|---|
| Pages (from-to) | 358-368 |
| Number of pages | 11 |
| Journal | Journal of the National Cancer Institute |
| Volume | 94 |
| Issue number | 5 |
| Publication status | Published - 2002 Mar 6 |
| Externally published | Yes |
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ASJC Scopus subject areas
- Cancer Research
- Oncology
Cite this
Increased Ras expression and caspase-independent neuroblastoma cell death : Possible mechanism of spontaneous neuroblastoma regression. / Kitanaka, Chifumi; Kato, Keisuke; Ijiri, Rieko; Sakurada, Kaori; Tomiyama, Arata; Noguchi, Kohji; Nagashima, Yohji; Nakagawara, Akira; Momoi, Takashi; Toyoda, Yasunori; Kigasawa, Hisato; Nishi, Toshiji; Shirouzu, Mikako; Yokoyama, Shigeyuki; Tanaka, Yukichi; Kuchino, Yoshiyuki.
In: Journal of the National Cancer Institute, Vol. 94, No. 5, 06.03.2002, p. 358-368.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Increased Ras expression and caspase-independent neuroblastoma cell death
T2 - Possible mechanism of spontaneous neuroblastoma regression
AU - Kitanaka, Chifumi
AU - Kato, Keisuke
AU - Ijiri, Rieko
AU - Sakurada, Kaori
AU - Tomiyama, Arata
AU - Noguchi, Kohji
AU - Nagashima, Yohji
AU - Nakagawara, Akira
AU - Momoi, Takashi
AU - Toyoda, Yasunori
AU - Kigasawa, Hisato
AU - Nishi, Toshiji
AU - Shirouzu, Mikako
AU - Yokoyama, Shigeyuki
AU - Tanaka, Yukichi
AU - Kuchino, Yoshiyuki
PY - 2002/3/6
Y1 - 2002/3/6
N2 - Background: Neuroblastoma undergoes spontaneous regression frequently during its natural course. Although programmed cell death (PCD) has been implicated in this process, accumulating evidence suggests that apoptosis, a form of PCD that is regulated by caspases, may not play a major role. We examined the mechanism(s) of spontaneous regression of neuroblastoma, focusing on the role of Ras, a favorable prognostic marker of neuroblastoma. Methods: Tumor tissues were analyzed by light microscopy, electron microscopy, and immunohistochemistry to examine cell degeneration and expression of Ras and several indicators of PCD. Cell degeneration was also studied in vitro in neuroblastoma cells transfected with the H-ras gene. All statistical tests were two-sided. Results: Immunohistochemical analyses revealed that Ras expression was increased in areas of cellular degeneration lacking apoptotic characteristics. The degenerating cells were fragmented without nuclear condensation and, essentially, lacked caspase-3 activation and apoptotic DNA fragmentation. These cells had ultrastructural features of autophagic degeneration, another form of PCD that is distinct from apoptosis. Focal areas of degeneration associated with Ras expression were seen more frequently in tumors from patients detected in a mass-screening program (53 [60.9%] of 87) than in tumors from clinically detected, advanced-stage patients over 1 year of age (7[29.2%] of 24) (P=.006; chi-square test), suggesting a positive relationship between Ras-associated degeneration and probability of spontaneous regression/favorable prognosis. The characteristic features of Ras-associated nonapoptotic degeneration observed in tumor samples were recapitulated in vitro by transfection-mediated Ras expression, and Ras-mediated degeneration was augmented by TrkA, another favorable prognostic marker. Conclusions: High-level expression of H-Ras in neuroblastoma cells is associated with caspase cascade-independent, nonapoptotic PCD. This Ras-mediated nonapoptotic tumor cell death may play a key role in spontaneous regression of neuroblastoma.
AB - Background: Neuroblastoma undergoes spontaneous regression frequently during its natural course. Although programmed cell death (PCD) has been implicated in this process, accumulating evidence suggests that apoptosis, a form of PCD that is regulated by caspases, may not play a major role. We examined the mechanism(s) of spontaneous regression of neuroblastoma, focusing on the role of Ras, a favorable prognostic marker of neuroblastoma. Methods: Tumor tissues were analyzed by light microscopy, electron microscopy, and immunohistochemistry to examine cell degeneration and expression of Ras and several indicators of PCD. Cell degeneration was also studied in vitro in neuroblastoma cells transfected with the H-ras gene. All statistical tests were two-sided. Results: Immunohistochemical analyses revealed that Ras expression was increased in areas of cellular degeneration lacking apoptotic characteristics. The degenerating cells were fragmented without nuclear condensation and, essentially, lacked caspase-3 activation and apoptotic DNA fragmentation. These cells had ultrastructural features of autophagic degeneration, another form of PCD that is distinct from apoptosis. Focal areas of degeneration associated with Ras expression were seen more frequently in tumors from patients detected in a mass-screening program (53 [60.9%] of 87) than in tumors from clinically detected, advanced-stage patients over 1 year of age (7[29.2%] of 24) (P=.006; chi-square test), suggesting a positive relationship between Ras-associated degeneration and probability of spontaneous regression/favorable prognosis. The characteristic features of Ras-associated nonapoptotic degeneration observed in tumor samples were recapitulated in vitro by transfection-mediated Ras expression, and Ras-mediated degeneration was augmented by TrkA, another favorable prognostic marker. Conclusions: High-level expression of H-Ras in neuroblastoma cells is associated with caspase cascade-independent, nonapoptotic PCD. This Ras-mediated nonapoptotic tumor cell death may play a key role in spontaneous regression of neuroblastoma.
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M3 - Article
VL - 94
SP - 358
EP - 368
JO - Journal of the National Cancer Institute
JF - Journal of the National Cancer Institute
SN - 0027-8874
IS - 5
ER -