Drug resistance remains a major clinical obstacle to successful treatment of cancer. As posttranslational modification is becoming widely recognized to affect the function of oncoproteins, targeting specific posttranslational protein modification provides an attractive strategy for anticancer drug development. CD147 is a transmembrane glycoprotein contributing to chemo-resistance of cancer cells in a variety of human malignancies. Ubiquitination is an important posttranslational modification mediating protein degradation. Degradation of oncoproteins, CD147 included, emerges as an attractive alternative for tumor inhibition. However, the ubiquitination of CD147 remains elusive. Here in this study, we found that deletion of the CD147 intracellular domain (CD147-ICD) prolonged the half-life of CD147 in HEK293T cells, and we identified that CD147-ICD interacts with FBXO22 using mass spectrometry and Western blot. Then, we demonstrated that FBXO22 mediates the polyubiquitination and degradation of CD147 by recognizing CD147-ICD. While knocking down of FBXO22 prolonged the half-life of CD147 in HEK293T cells, we found that FBXO22 regulates CD147 protein turnover in SMMC-7721, Huh-7 and A549 cells. Moreover, we found that the low level of FBXO22 contributes to the accumulation of CD147 and thereafter the cisplatin resistance of A549/DDP cells. To conclude, our study demonstrated that FBXO22 mediated the polyubiquitination and degradation of CD147 by interacting with CD147-ICD, and CD147 polyubiquitination by FBXO22 reversed cisplatin resistance of tumor cells.
The treatment of advanced triple-negative breast cancer, which failed in first-line or second-line therapy, is a significant challenge. We conducted this retrospective study to explore the efficacy and safety of apatinib and capecitabine as the third-line treatment for advanced triple-negative breast cancer. This retrospective study involved 44 advanced triple-negative breast cancer patients who failed in first-line or second-line therapy in Tangshan People's Hospital from January 2016 to February 2017. Twenty-two patients received apatinib and capecitabine, while 22 patients were treated with capecitabine monotherapy as third-line therapy. The progression-free survival (PFS), objective response rate (ORR), disease control rate (DCR), and adverse events were compared between 2 groups. The apatinib and capecitabine group exhibited a higher PFS than capecitabine group (P = .001). Meanwhile, ORR and DCR in apatinib and capecitabine group were better than in capecitabine group (P = .042; .016). The 2 groups showed no significant difference in adverse events except degree I-II bleeding (P = .021). Both the apatinib and capecitabine and the capecitabine regimens revealed good tolerability. The apatinib and capecitabine regimen can achieve a better efficacy and similar serious adverse events compared with capecitabine regimen as the third-line treatment for advanced triple-negative breast cancer.
Immune checkpoint inhibitors, a type of immunotherapy, have demonstrated optimal treatment efficacy in inducing durable antitumor responses in various cancers. Cytokine-release syndrome is a rare i... Plain language summary Immune checkpoint inhibitors (ICIs) have shown revolutionary efficacy in the treatment of multiple cancers. Cytokine-release syndrome (CRS) is a common and lethally adverse e...
Hepatocellular carcinoma (HCC) is currently the third most common cause of cancer-related death in the Asia-Pacific region. Our previous work showed that knockdown of CD98 significantly inhibits malignant HCC cell phenotypes in vitro and in vivo. The level of CD98 in the membrane is tightly regulated to mediate complex processes associated with cell–cell communication and intracellular signaling. In addition, the intracellular domain of CD98 (CD98-ICD) seems to be of vital importance for recycling CD98 to the membrane after it is endocytosed. The intracellular and transmembrane domains of CD98 associate with β-integrins (primarily β1 but also β3), and this association is essential for CD98 mediation of integrin-like signaling and complements dominant suppression of β1-integrin. We speculated that isolated CD98-ICD would similarly suppress β1-integrin activation and inhibit the malignant behaviors of cancer cells. In particular, the exact role of CD98-ICD has not been studied independently in HCC. In this study, we found that ectopic expression of CD98-ICD inhibited the malignant phenotypes of HCC cells, and the mechanism possibly involves β1-integrin suppression. Moreover, the expression levels of CD98, β1-integrin-A (the activated form of β1-integrin) and Ki-67 were significantly increased in HCC tissues relative to those of normal liver tissues. Therefore, our preliminary study indicates that ectopic CD98-ICD has an inhibitory role in the malignant development of HCC, and shows that CD98-ICD acts as a dominant negative mutant of CD98 that attenuates β1-integrin activation. CD98-ICD may emerge as a promising candidate for antitumor treatment.
Rationale: Vulvar melanoma is a rare and aggressive tumor with a high risk of local recurrence and distant metastasis. The prognosis is poor with a 5-year overall survival rate of only 46.6%. Management of vulvar melanoma remains a clinical challenge. Recent evidences have shown that immune checkpoint inhibitors are effective in the treatment of vulvar melanoma. Patient concerns and diagnoses: A 63-year-old woman with vulvar malignant melanoma suffered inguinal lymph node metastasis after vulvectomy and chemotherapy. She underwent inguinal lymph node dissection and inguinal radiotherapy. The tumor progressed again and she received immunotherapy. Interventions: The tumor progressed again, and she was admitted to our hospital and received toripalimab combined with apatinib and abraxane. Outcomes: After 6 cycles of immunotherapy, the efficacy achieved partial remission. And with toripalimab as maintenance therapy, the patient achieved durable antitumor efficacy and good safety. Lessons: In this rare case, the patient with metastatic vulvar malignant melanoma had durable antitumor efficacy and good safety when receiving toripalimab.