Induction of cell death and inhibition of cell survival are the main principles of cancer therapy. Resistance to chemotherapeutic agents is a major problem in oncology, which limits the effectiveness of anticancer drugs. A variety of factors contribute to drug resistance, including host factors, specific genetic or epigenetic alterations in the cancer cells and so on. Although various mechanisms by which cancer cells become resistant to anticancer drugs in the microenvironment have been well elucidated, how to circumvent this resistance to improve anticancer efficacy remains to be defined. Autophagy, an important homeostatic cellular recycling mechanism, is now emerging as a crucial player in response to metabolic and therapeutic stresses, which attempts to maintain/restore metabolic homeostasis through the catabolic lysis of excessive or unnecessary proteins and injured or aged organelles. Recently, several studies have shown that autophagy constitutes a potential target for cancer therapy and the induction of autophagy in response to therapeutics can be viewed as having a prodeath or a prosurvival role, which contributes to the anticancer efficacy of these drugs as well as drug resistance. Thus, understanding the novel function of autophagy may allow us to develop a promising therapeutic strategy to enhance the effects of chemotherapy and improve clinical outcomes in the treatment of cancer patients.

/pdf/autophagy-and-chemotherapy-resistance-a-promising-2pz6sno24p.pdf

Autophagy and chemotherapy resistance: a promising therapeutic target for cancer treatment

Broad targeting of resistance to apoptosis in cancer.

Multidrug resistance (MDR) occurs frequently after long-term chemotherapy, resulting in refractory cancer and tumor recurrence. Therefore, combatting MDR is an important issue. Autophagy, a self-degradative system, universally arises during the treatment of sensitive and MDR cancer. Autophagy can be a double-edged sword for MDR tumors: it participates in the development of MDR and protects cancer cells from chemotherapeutics but can also kill MDR cancer cells in which apoptosis pathways are inactive. Autophagy induced by anticancer drugs could also activate apoptosis signaling pathways in MDR cells, facilitating MDR reversal. Therefore, research on the regulation of autophagy to combat MDR is expanding and is becoming increasingly important. We summarize advanced studies of autophagy in MDR tumors, including the variable role of autophagy in MDR cancer cells.

/pdf/autophagy-and-multidrug-resistance-in-cancer-2865ylyoc3.pdf

Autophagy and multidrug resistance in cancer

MicroRNAs (miRNAs) are small non-coding RNAs with a length of about 19–25 nt, which can regulate various target genes and are thus involved in the regulation of a variety of biological and pathological processes, including the formation and development of cancer. Drug resistance in cancer chemotherapy is one of the main obstacles to curing this malignant disease. Statistical data indicate that over 90% of the mortality of patients with cancer is related to drug resistance. Drug resistance of cancer chemotherapy can be caused by many mechanisms, such as decreased antitumor drug uptake, modified drug targets, altered cell cycle checkpoints, or increased DNA damage repair, among others. In recent years, many studies have shown that miRNAs are involved in the drug resistance of tumor cells by targeting drug-resistance-related genes or influencing genes related to cell proliferation, cell cycle, and apoptosis. A single miRNA often targets a number of genes, and its regulatory effect is tissue-specific. In this review, we emphasize the miRNAs that are involved in the regulation of drug resistance among different cancers and probe the mechanisms of the deregulated expression of miRNAs. The molecular targets of miRNAs and their underlying signaling pathways are also explored comprehensively. A holistic understanding of the functions of miRNAs in drug resistance will help us develop better strategies to regulate them efficiently and will finally pave the way toward better translation of miRNAs into clinics, developing them into a promising approach in cancer therapy.

/pdf/the-role-and-mechanisms-of-action-of-micrornas-in-cancer-3reepz2l36.pdf

The role and mechanisms of action of microRNAs in cancer drug resistance.

Chemotherapy is a reasonable alternative to cystectomy in patients with invasive and advanced bladder cancer. However, bladder cancer cells often develop drug resistance to these therapies, and ~ 50% of patients with advanced bladder cancer do not respond to chemotherapy. Recent studies have shown that long non-coding RNA (lncRNA) is involved in the development of chemoresistance. Here we investigated the role of the urothelial cancer-associated 1 (UCA1) lncRNA in cisplatin resistance during chemotherapy for bladder cancer. We showed that cisplatin-based chemotherapy results in up-regulation of UCA1 expression in patients with bladder cancer. Similarly, UCA1 levels are increased in cisplatin-resistant bladder cancer cells. Over-expression of UCA1 significantly increases the cell viability during cisplatin treatment, whereas UCA1 knockdown reduces the cell viability during cisplatin treatment. UCA1 inhibition also partially overcomes drug resistance in cisplatin-resistant T24 cells. Furthermore, we showed that UCA1 positively regulates expression of wingless-type MMTV integration site family member 6 (Wnt6) in human bladder cancer cell lines. UCA1 and Wnt6 expression is also positively correlated in vivo. Up-regulation of UCA1 activates Wnt signaling in a Wnt6-dependent manner. We finally demonstrate that UCA1 increases the cisplatin resistance of bladder cancer cells by enhancing the expression of Wnt6, and thus represents a potential target to overcome chemoresistance in bladder cancer.

https://febs.onlinelibrary.wiley.com/doi/pdf/10.1111/febs.12737

Long non-coding RNA UCA1 increases chemoresistance of bladder cancer cells by regulating Wnt signaling.

Cisplatin-induced downregulation of miR-199a-5p increases drug resistance by activating autophagy in HCC cell

Upregulated miR-130a increases drug resistance by regulating RUNX3 and Wnt signaling in cisplatin-treated HCC cell.

We investigated the overall situation of LT for BA in mainland China and analyzed their survival outcomes based on data from CLTR. Between January 1996 and December 2013, 509 liver transplants for BA were performed in mainland China and were included in this study. Patients' median age was 9.6 months (range: 4.8-175.2 months). KP was previously performed in 194 cases (38.1%). Grafts from living donors were used in 380 cases (74.7%). Era I (1996.1-2010.12) and era II (2011.1-2013.12) comprised 151 cases (29.7%) and 358 cases (70.3%), respectively. Twenty-five centers had performed at least one liver transplant for children with BA. Centers from Shanghai (197 cases), Tianjin (143 cases) and Beijing (81 cases) involved 82.7% of the 509 cases. One- and five-yr graft survival rates were 84.7% and 72.6%, respectively. Split grafts, center volume <20, GRWR ≥4.0%, and steroid-free immunosuppression regimen were independent risk factors for graft survival. In conclusion, the dramatic expansion of pediatric liver transplant programs in mainland China has enabled improved survival for those children affected by this devastating disease. However, screening of BA in neonates should be emphasized throughout the country to enhance early referrals for KP.

Liver transplantation for biliary atresia: A nationwide investigation from 1996 to 2013 in mainland China

Tacrolimus (TAC) is the backbone of an immunosuppressive drug used in most solid organ transplant recipients. A single nucleotide polymorphism (SNP) at position 6986G>A in CYP3A5 has been notably involved in the pharmacokinetic variability of TAC. It is hypothesized that CYP3A5 genotyping in patients may provide a guideline for TAC therapeutic regimen. To further evaluate the impact of CYP3A5 variants in donors and recipients, ABCB1 and ACE SNPs in recipients on TAC disposition, clinical and laboratory data were retrospectively reviewed from 90 pediatric patients with liver transplantation and their corresponding donors after 1 year of transplantation. The recipients with CYP3A5 *1/*1 or *1/*3 required more time to achieve TAC therapeutic range during the induction phase, and needed more upward dose during the late induction and the maintained phases, with lower C/D ratio, compared with those with CYP3A5 *3/*3. And donor CYP3A5 genotypes were found to impact on TAC trough concentrations after liver transplantation. No association between ABCB1 or ACE genotypes and TAC disposition post-transplantation was found. These results strongly suggest that CYP3A5 genotyping both in recipient and donor, not ABCB1 or ACE is necessary for establishing a personalized TAC dosage regimen in pediatric liver transplant patients.

/pdf/personalized-tacrolimus-dose-requirement-by-cyp3a5-but-not-1fpt3ctcvw.pdf

Personalized Tacrolimus Dose Requirement by CYP3A5 but Not ABCB1 or ACE Genotyping in Both Recipient and Donor after Pediatric Liver Transplantation

LDLT is a well-established treatment for most terminal liver diseases in children. Survival rates have improved, yet few studies have considered HRQoL or sleep problems in LDLT recipients. In this cross-sectional study, we enrolled 51 children who had undergone LDLT in Renji Hospital. PedsQL(™) 4.0 Generic Core Scales, PedsQL(™) 3.0 Transplant Module, and Pediatric Sleep Questionnaire were used to assess outcomes. Of all participants, 11.8% (6/51) reported low total HRQoL scores. Participants' scores on most HRQoL subscales were comparable to the scores of healthy children. However, compared with solid organ transplant recipients, LDLT recipients scored significantly lower in About My Medicines II (t = 3.092, p = 0.002) and Worry (t = 2.760, p = 0.006). Sleep problems (41.2%) were common among participants. Hierarchical regression analyses showed that SRBD accounted for significant variance in HRQoL on total generic HRQoL (R(2) = 0.446, p < 0.001), psychosocial health (R(2) = 0.372, p = 0.001), physical health (R(2) = 0.345, p = 0.003), total transplant-specific HRQoL (R(2) = 0.514, p < 0.001), About My Medicines I (R(2) = 0.365, p = 0.013), My Transplant and Others (R(2) = 0.334, p = 0.005), Pain and Hurt (R(2) = 0.544, p < 0.001), Worry (R(2) = 0.401, p = 0.001), Treatment Anxiety (R(2) = 0.526, p < 0.001), How I Look (R(2) = 0.221, p = 0.040), and Communication (R(2) = 0.343, p = 0.012). In conclusion, sleep problems are non-negligible in children after LDLT and predicted significant variance on HRQoL.

Conghuan Shen

Papers

Cisplatin-induced downregulation of miR-199a-5p increases drug resistance by activating autophagy in HCC cell

Upregulated miR-130a increases drug resistance by regulating RUNX3 and Wnt signaling in cisplatin-treated HCC cell.

Liver transplantation for biliary atresia: A nationwide investigation from 1996 to 2013 in mainland China

Personalized Tacrolimus Dose Requirement by CYP3A5 but Not ABCB1 or ACE Genotyping in Both Recipient and Donor after Pediatric Liver Transplantation

Health-related quality of life and sleep among Chinese children after living donor liver transplantation.