Silibinin suppresses NPM-ALK, potently induces apoptosis and enhances chemosensitivity in ALK-positive anaplastic large cell lymphoma

The Long Non-Coding RNA MIR503HG Enhances Proliferation of Human ALK-Negative Anaplastic Large-Cell Lymphoma

Anaplastic lymphoma kinase (ALK)-negative anaplastic large-cell lymphoma (ALCL) is a rare type of highly malignant, non-Hodgkin lymphoma. Currently, only a few gene rearrangements have been linked to ALK-negative ALCL progression. However, the specific molecular mechanisms underlying the growth of ALK-negative ALCL tumors remain unclear. Here, we investigated aberrantly expressed, long non-coding RNAs (lncRNAs) in ALK-negative ALCL and assessed their potential biological function. MIR503HG (miR-503 host gene) was highly expressed in ALK-negative cell lines and was significantly upregulated in tumors in mice formed from ALK-negative ALCL cell lines. Depletion of MIR503HG suppressed tumor cell proliferation in vivo and in vitro; conversely, its overexpression enhanced tumor cell growth. MIR503HG-induced proliferation was mediated by the induction of microRNA-503 (miR-503) and suppression of Smurf2, resulting in stabilization of the tumor growth factor-β receptor (TGFBR) and enhanced tumor cell growth. Collectively, these findings support a potential role for MIR503HG in cancer cell proliferation through the miR-503/Smurf2/TGFBR axis and indicate that MIR503HG is a potential marker in ALK-negative ALCL.

Silibinin: an old drug for hematological disorders

Introduction

Silibinin (silybin), a non-toxic natural polyphenolic flavonoid, is the principal and the most biologically active component of silymarin. It is efficient in the treatment of acute and chronic liver disorders caused by toxins, drug, alcohol, hepatitis, and gall bladder disorders. Further, in our previous studies, we explored the anti-cancer efficacy in common cancers, such as lung, prostatic, colon, breast, bladder, as well as, hepatocellular carcinoma. Interestingly, silibinin is still not solely limited to the treatment of these diseases. Recent research endeavors suggest that silibinin may function diversely and serve as a novel therapy for hematological disorders.

Areas covered

It discovered several interesting viewpoints in the widely studied mechanisms of silibinin in the hematological disorders.

Expert commentary

In this report, we review the up-to-date findings of more potency roles of silibinin in β-thalassemia (β-TM), acute myeloid leukemia (AML), anaplastic large cell lymphoma (ALCL) and multiple myelomas (MM) therapy and attempt to clarify the mechanisms underlying its effects. There are two viewpoints: First, The functional mechanisms of silibinin in AML cells via regulating cell differentiation to exert anti-cancer effect; Second, combination treatment strategy may be a good choice.

The long non-coding RNA LINC01013 enhances invasion of human anaplastic large-cell lymphoma

Anaplastic large-cell lymphoma (ALCL) is a rare type of highly malignant, non-Hodgkin lymphoma (NHL). Currently, only studies on the chimeric oncogene NPM-ALK have reported a link to ALCL progression. However, the specific molecular mechanisms underlying the invasion of ALCL are still unclear. Here, we sought to investigate differentially expressed, long non-coding RNAs (lncRNAs) in ALCL and their potential biological function. Our microarray analyses revealed that LINC01013, a novel non-coding RNA gene, was highly expressed in clinical specimens of ALCL and was significantly upregulated in invasive ALCL cell lines. Knockdown of LINC01013 suppressed tumor cell invasion; conversely, its overexpression enhanced tumor cell invasion. LINC01013-induced invasion was mediated by activation of the epithelial-to-mesenchymal transition (EMT)-associated proteins, snail and fibronectin. Specifically, LINC01013 induced snail, resulting in activation of fibronectin and enhanced ALCL cell invasion. Collectively, these findings support a potential role for LINC01013 in cancer cell invasion through the snail-fibronectin activation cascade and suggest that LINC01013 could potentially be utilized as a metastasis marker in ALCL.

Role of p53 in silibinin-mediated inhibition of ultraviolet B radiation-induced DNA damage, inflammation and skin carcinogenesis

Non-melanoma skin cancers (NMSC) are a growing problem given that solar ultraviolet B (UVB) radiation exposure is increasing most likely due to depletion of the atmospheric ozone layer and lack of adequate sun protection. Better preventive methods are urgently required to reduce UV-caused photodamage and NMSC incidence. Earlier, we have reported that silibinin treatment activates p53 and reduces photodamage and NMSC, both in vitro and in vivo; but whether silibinin exerts its protective effects primarily through p53 remains unknown. To address this question, we generated p53 heterozygous (p53^+/-) and p53 knockout (p53^-/-) mice on SKH-1 hairless mouse background, and assessed silibinin efficacy in both short- and long-term UVB exposure experiments. In the chronic UVB-exposed skin tumorigenesis study, compared to p53^+/+ mice, p53^+/- mice developed skin tumors earlier and had higher tumor number, multiplicity and volume. Silibinin topical treatment significantly reduced the tumor number, multiplicity and volume in p53^+/+ mice but silibinin' protective efficacy was significantly compromised in p53^+/- mice. Additionally, silibinin treatment failed to inhibit precursor skin cancer lesions in p53^-/- mice but improved the survival of the mice. In short-term studies, silibinin application accelerated the removal of UVB-induced DNA damage in p53^+/+ mice while its efficacy was partially compromised in p53^-/- mice. Interestingly, silibinin treatment also inhibited the UVB-induced inflammatory markers in skin tissue. These results further confirmed that absence of the p53 allele predisposes mice to photodamage and photocarcinogenesis, and established that silibinin mediates its protection against UVB-induced photodamage, inflammation and photocarcinogenesis partly through p53 activation.

Primary gastric anaplastic lymphoma kinase-negative anaplastic large-cell lymphoma

INTRODUCTION

Most primary stomach lymphomas are now recognized to originate from B-cell. Primary gastric anaplastic lymphoma kinase (ALK)-negative anaplastic large-cell lymphoma (ALCL) as shown in this case is very rare.

CASE REPORT

A 59-year-old man presented with a 1-month history of epigastric pain. Computed tomography showed a tumor in the stomach with perigastric lymphadenopathy. Biopsy of the tumor with gastroendoscopy showed ALCL. Bone marrow aspiration and trephine biopsy showed no infiltration. A diagnosis of primary gastric ALK-negative ALCL was made. The patient was first treated with four cycles of cyclophosphamide, doxorubicin, vincristine, prednisone (CHOP) regimen, but his condition did not show improvement. Then he was treated with two cycles of hyperfractionated cyclophosphamide, vincristine, doxorubicin, and dexamethasone/methotrexate and cytarabine (Hyper-CVAD/MA) regimen. In spite of these treatments, he still died of disease progression.

CONCLUSION

The prognosis of ALK-negative ALCLs is usually worse than ALK-positive ALCLs. In this case, the patient was not responsive to a multidrug chemotherapy with CHOP and Hyper-CVAD/MA.

Expression patterns of the activator protein-1 (AP-1) family members in lymphoid neoplasms

The activator protein-1 (AP-1) is a dimeric transcription factor composed of proteins belonging to the Jun (c-Jun, JunB and JunD), Fos (c-Fos, FosB, Fra1 and Fra2) and activating transcription factor protein families. AP-1 is involved in various cellular events including differentiation, proliferation, survival and apoptosis. Deregulated expression of AP-1 transcription factors is implicated in the pathogenesis of various lymphomas such as classical Hodgkin lymphomas, anaplastic large cell lymphomas, diffuse large B cell lymphomas and adult T cell leukemia/lymphoma. The main purpose of this review is the analysis of the expression patterns of AP-1 transcription factors in order to gain insight into the histophysiology of lymphoid tissues and the pathology of lymphoid malignancies.