Erb-b2 receptor tyrosine kinase 2 (ErbB2) is an oncogene that frequently overexpressed in a subset of cancers. Anti-ErbB2 therapies have been developed to treat these types of cancers. However, less is known about how anti-ErbB2 drugs affect the trafficking and degradation of ErbB2. We demonstrate that the reversible and irreversible tyrosine kinase inhibitors (TKIs) differentially modulate the subcellular trafficking and downregulation of ErbB2. Only the irreversible TKIs can induce the loss of ErbB2 expression, which is not dependent on proteasome or lysosome. The irreversible TKIs promote ErbB2 endocytosis from plasma membrane and enhance the ErbB2 accumulation at endosomes. The endocytosis of ErbB2 is mediated by a dynamin-dependent but clathrin-independent mechanism. Blocking of ErbB2 endocytosis can impair the TKI-induced ErbB2 downregulation.

Tumor recurrence rate after surgery or ablation of hepatocellular carcinoma (HCC) is as high as 70%. However, there are no widely accepted adjuvant therapies; therefore, no treatment has been recommended by guidelines from the American Association for the Study of Liver Disease or the European Association for the Study of the Liver. All the registered trials failed to find any treatment to prolong recurrence-free survival, which is the primary outcome in most studies, including sorafenib. Some investigator-initiated studies revealed that anti-hepatitis B virus agents, interferon-α, transcatheter chemoembolization, chemokine-induced killer cells, and other treatments prolonged patient recurrence-free survival or overall survival after curative therapies. In this review, we summarize the current status of adjuvant treatments for HCC and explain the challenges associated with designing a clinical trial for adjuvant therapy. Promising new treatments being used as adjuvant therapy, especially anti-PD-1 antibodies, are also discussed.

Liver cancer, mostly hepatocellular carcinoma (HCC), is the second leading cause of cancer mortality globally. Most patients were diagnosed at an advanced stage, and systemic therapy is the standard of care. All the approved systemic therapies for HCC are molecular targeted therapies with anti-angiogenic effects targeting the vascular endothelial growth factor signaling pathway. Sorafenib and lenvatinib are the first-line treatment, and regorafenib, ramucirumab, and cabozantinib are second-line treatment options. Although anti-PD-1 antibodies, including nivolumab and pembrolizumab, demonstrated promising anti-tumor effects as monotherapy for advanced HCC in phase II clinical trials, both failed in phase III studies. Anti-angiogenic treatment remains the backbone of systemic therapy for HCC. In this review, we summarized the approved anti-angiogenic medicines and discussed the potential strategies to improve the efficacy of anti-angiogenic therapy, including combination therapy with other treatments, and discussed the approaches to overcome the drawbacks of anti-angiogenic therapies.

As three decades ago, it was reported that adoptive T cell immunotherapy by infusion of autologous tumor infiltrating lymphocytes (TILs) mediated objective cancer regression in patients with metastatic melanoma. A new era of T cell immunotherapy arose since the improvement and clinical use of anti-CD19 chimeric antigen receptor T cells (CAR-T) for the treatment of refractory and relapsed B lymphocyte leukemia. However, several challenges and difficulties remain on the way to reach generic and effective T cell immunotherapy, including lacking a generic method for generating anti-leukemia-specific T cells from every patient. Here, we summarize the current methods of generating anti-leukemia-specific T cells, and the promising approaches in the future.

The ALK gene fusion has been identified as a new driver gene in non-small cell lung cancer (NSCLC). It includes the EML4-ALK rearrangement as a recurring event that renders the tumor sensitive to ALK tyrosine kinase inhibitor crizotinib. In addition, several other fusion partners to ALK kinase domain (eg, TFG, KLC1, and KIF5B) have been identified in NSCLC. However, clinical data relevant to response in lung cancer harboring these rare ALK translocations are not fully available. A nonsmoking Chinese male originally diagnosed with \"stage Ib lung adenocarcinoma\" showed metastases in regional lymph nodes, pleura, and bone 1 year after surgery. The patient refused invasive tissue biopsy, and chemotherapy was administrated, which failed as a first- and second-line treatment. We then identified a rare fusion gene of ALK and Striatin (STRN) using next-generation sequencing (NGS)-based circulating tumor DNA (ctDNA) analysis. The NGS of the patient\'s originally paraffin-embedded surgical tumor samples also indicated the fusion. Reverse transcription-polymerase chain reaction and Sanger sequencing further confirmed the results. The STRN-ALK involves the fusion of exon 3 of STRN retaining a coiled-coil domain to exon 20 of ALK containing a kinase domain. The patient was treated with crizotinib and showed excellent clinical, radiographic, and molecular response. Repetitive dynamic ctDNA analysis revealed that the fraction of molecular alterations in plasma was closely associated with response to crizotinib treatment. This is the first clinical evidence involving advanced NSCLC due to a rare STRN-ALK fusion and has been effectively treated with crizotinib.

Overexpressing of ATP-binding cassette (ABC) transporters is the essential cause of multidrug resistance (MDR), which is a significant hurdle to the success of chemotherapy in many cancers. Therefore, inhibiting the activity of ABC transporters may be a logical approach to circumvent MDR. Olmutinib is an epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI), which has been approved in South Korea for advanced EGFR T790M-positive non-small cell lung cancer (NSCLC). Here, we found that olmutinib significantly increased the sensitivity of chemotherapy drug in ABCG2-overexpressing cells. Furthermore, olmutinib could also increase the retention of doxorubicin (DOX) and rhodamine 123 (Rho 123) in ABC transporter subfamily G member 2 (ABCG2)-overexpressing cells. In addition, olmutinib was found to stimulate ATPase activity and inhibit photolabeling of ABCG2 with [125I]-iodoarylazidoprazosin (IAAP). However, olmutinib neither altered ABCG2 expression at protein and mRNA levels nor blocked EGFR, Her-2 downstream signaling of AKT and ERK. Importantly, olmutinib enhanced the efficacy of topotecan on the inhibition of S1-MI-80 cell xenograft growth. All the results suggest that olmutinib reverses ABCG2-mediated MDR by binding to ATP bind site of ABCG2 and increasing intracellular chemotherapeutic drug accumulation. Our findings encouraged to further clinical investigation on combination therapy of olmutinib with conventional chemotherapeutic drugs in ABCG2-overexpressing cancer patients.

Although many strategies have been developed for non-small cell lung cancer (NSCLC), more secondary and further treatments are needed due to drug resistance or tumor recurrence. Apatinib is a novel oral antiangiogenic agent and in this study, we aim to investigate the clinical value of apatinib in heavily pretreated NSCLC. Here, we reported the characteristics, efficacy and adverse events of three patients treated with apatinib (500 mg/day). We also summarized the currently available evidence and ongoing clinical trials regarding the use of apatinib in NSCLC. Two cases of adenocarcinoma and one case of squamous cell carcinoma were treated with apatinib due to disease progression after previous treatments of chemotherapy and epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI). All patients responded to apatinib rapidly and underwent drug resistance shortly afterwards. The patient with squamous cell carcinoma died of hemoptysis. Other adverse events were acceptable. All previous relevant studies were compared and showed similar results but a longer progression-free survival. Additionally, ongoing clinical trials were systematically searched and listed. In conclusion, apatinib shows some efficacy in heavily treated NSCLC and generally tolerable toxicity in non-squamous NSCLC. More solid evidence will be accessible in near future.

Renal cell carcinoma (RCC) is the most common renal cancer, and has a poor prognosis in individuals with metastases (mRCC). In this report, we describe a 48-year-old woman with unresectable multiple liver metastases and a colonic metastasis of RCC who was treated with sunitinib in combination with hepatic microwave ablation and obtained a clinical and pathological complete remission. We consider that sunitinib combined with microwave ablation can prevent unresectable hepatic metastases of RCC from evolving, and that sunitinib alone can achieve clinical and pathological remission in patients with colonic metastasis of RCC.

The frontline tyrosine kinase inhibitor (TKI) imatinib has revolutionized the treatment of patients with chronic myeloid leukemia (CML). However, drug resistance is the major clinical challenge in the treatment of CML. The Hedgehog (Hh) signaling pathway and autophagy are both related to tumorigenesis, cancer therapy, and drug resistance. This study was conducted to explore whether the Hh pathway could regulate autophagy in CML cells and whether simultaneously regulating the Hh pathway and autophagy could induce cell death of drug-sensitive or -resistant BCR-ABL(+) CML cells. Our results indicated that pharmacological or genetic inhibition of Hh pathway could markedly induce autophagy in BCR-ABL(+) CML cells. Autophagic inhibitors or ATG5 and ATG7 silencing could significantly enhance CML cell death induced by Hh pathway suppression. Based on the above findings, our study demonstrated that simultaneously inhibiting the Hh pathway and autophagy could markedly reduce cell viability and induce apoptosis of imatinib-sensitive or -resistant BCR-ABL(+) cells. Moreover, this combination had little cytotoxicity in human peripheral blood mononuclear cells (PBMCs). Furthermore, this combined strategy was related to PARP cleavage, CASP3 and CASP9 cleavage, and inhibition of the BCR-ABL oncoprotein. In conclusion, this study indicated that simultaneously inhibiting the Hh pathway and autophagy could potently kill imatinib-sensitive or -resistant BCR-ABL(+) cells, providing a novel concept that simultaneously inhibiting the Hh pathway and autophagy might be a potent new strategy to overcome CML drug resistance.

Panitumumab, as a commercially available antibody, is an effective anticancer therapeutic against epidermal growth factor receptor (EGFR), although it exerts weak antibody-dependent cell-mediated cytotoxicity (ADCC) activity owing to its IgG2 nature. Here, we firstly engineered panitumumab by grafting its variable region into an IgG1 backbone. The engineered panitumumab (denoted as Pan) retained binding activity identical to the parental antibody while exhibiting stronger ADCC activity in vitro and more potent antitumor effect in vivo. To further enhance the target selectivity of Pan, we generated Pan-P by tethering an epitope-blocking peptide to Pan via a tumor-specific protease selective linker. Pan-P showed almost 40-fold weaker affinity compared with Pan, but functional activity was restored to a similar extent as Pan when Pan-P was selectively activated by urokinase-type plasminogen activator (uPA). More importantly, targeted localization of Pan-P was observed in tumor samples from colorectal cancer (CRC) patients and tumor-bearing nude mice, strongly indicating that specific activation also existed ex vivo and in vivo. Furthermore, Pan-P also exhibited effective in vivo antitumor potency similar to Pan. Taken together, our data evidence the enhanced antitumor potency and excellent target selectivity of Pan-P, suggesting its potential use for minimizing on-target toxicity in anti-EGFR therapy.