Sasi Sharath P, Bae Sanggyu, Song Jin, Perepletchikov Aleksandr, Schneider Douglas, Carrozza Joseph, Yan Xinhua, Kishore Raj, Enderling Heiko, Goukassian David A
Cardiovascular Research Center, GeneSys Research Institute, Boston, Massachusetts, United States of America.
Cardiovascular Research Center, GeneSys Research Institute, Boston, Massachusetts, United States of America; Departments of Medicine and Pathology, Steward St. Elizabeth' Medical Center, Boston, Massachusetts, United States of America.
PLoS One. 2014 Mar 24;9(3):e92373. doi: 10.1371/journal.pone.0092373. eCollection 2014.
Tumor necrosis factor-alpha (TNF) binds to two receptors: TNFR1/p55-cytotoxic and TNFR2/p75-pro-survival. We have shown that tumor growth in p75 knockout (KO) mice was decreased more than 2-fold in Lewis lung carcinoma (LLCs). We hypothesized that selective blocking of TNFR2/p75 LLCs may sensitize them to TNF-induced apoptosis and affect the tumor growth. We implanted intact and p75 knockdown (KD)-LLCs (>90%, using shRNA) into wild type (WT) mice flanks. On day 8 post-inoculation, recombinant murine (rm) TNF-α (12.5 ng/gr of body weight) or saline was injected twice daily for 6 days. Tumor volumes (tV) were measured daily and tumor weights (tW) on day 15, when study was terminated due to large tumors in LLC+TNF group. Tubular bones, spleens and peripheral blood (PB) were examined to determine possible TNF toxicity. There was no significant difference in tV or tW between LLC minus (-) TNF and p75KD/LLC-TNF tumors. Compared to 3 control groups, p75KD/LLC+TNF showed >2-5-fold decreases in tV (p<0.001) and tW (p<0.0001). There was no difference in tV or tW end of study vs. before injections in p75KD/LLC+TNF group. In 3 other groups tV and tW were increased 2.7-4.5-fold (p<0.01, p<0.0002 and p<0.0001). Pathological examination revealed that 1/3 of p75KD/LLC+rmTNF tumors were 100% necrotic, the remaining revealed 40-60% necrosis. No toxicity was detected in bone marrow, spleen and peripheral blood. We concluded that blocking TNFR2/p75 in LLCs combined with intra-tumoral rmTNF injections inhibit LLC tumor growth. This could represent a novel and effective therapy against lung neoplasms and a new paradigm in cancer therapeutics.
肿瘤坏死因子-α(TNF)与两种受体结合:TNFR1/p55-细胞毒性受体和TNFR2/p75-促生存受体。我们已经表明,在Lewis肺癌(LLC)中,p75基因敲除(KO)小鼠的肿瘤生长减少了2倍以上。我们推测,选择性阻断TNFR2/p75 LLCs可能会使其对TNF诱导的凋亡敏感,并影响肿瘤生长。我们将完整的和p75基因敲低(KD)的LLCs(使用shRNA,敲低率>90%)植入野生型(WT)小鼠的侧腹。接种后第8天,每天两次注射重组鼠(rm)TNF-α(12.5 ng/克体重)或生理盐水,共6天。每天测量肿瘤体积(tV),并在第15天测量肿瘤重量(tW),此时由于LLC+TNF组肿瘤过大,研究终止。检查管状骨、脾脏和外周血(PB)以确定可能的TNF毒性。LLC减去(-)TNF组和p75KD/LLC-TNF组的tV或tW没有显著差异。与3个对照组相比,p75KD/LLC+TNF组的tV(p<0.001)和tW(p<0.0001)下降了2至5倍以上。在p75KD/LLC+TNF组中,研究结束时的tV或tW与注射前没有差异。在其他3组中,tV和tW增加了2.7至4.5倍(p<0.01、p<0.0002和p<0.0001)。病理检查显示,1/3 的p75KD/LLC+rmTNF肿瘤100%坏死,其余肿瘤坏死率为40-60%。在骨髓、脾脏和外周血中未检测到毒性。我们得出结论,阻断LLCs中的TNFR2/p75并结合瘤内注射rmTNF可抑制LLC肿瘤生长。这可能代表一种针对肺肿瘤新型且有效的治疗方法,也是癌症治疗的一种新范式。