Biotechnology: alternatives to human plasma-derived therapeutic proteins

Central nervous system relapse in a pediatric anaplastic large cell lymphoma patient with CLTC/ALK translocation treated with alectinib: A case report

BACKGROUND

The aberrant expression of the anaplastic lymphoma kinase (ALK) gene in ALK-positive (ALK+) anaplastic large cell lymphoma (ALCL) is usually due to t(2;5)/NPM-ALK. However, rarely, aberrant ALK expression can also result from a rearrangement of the ALK gene with various partner genes. Central nervous system (CNS) metastasis is very rare in ALK+ALCL. Patients with CNS involvement show an inferior prognosis.

CASE SUMMARY

Here, we present the case of an 8-year-old girl diagnosed with ALK+ALCL. She presented with fever, skin nodules, leg swelling, and abdominal pain over the preceding 6 mo. She had extensive involvement and showed an extraordinary rare translocation, t(2;17)/CLTC-ALK, as demonstrated by RNA-seq. She underwent chemotherapy as per ALCL99, followed by vinblastine (VBL) maintenance treatment, and achieved complete remission. However, she developed CNS relapse during VBL monotherapy. The patient achieved a durable second remission with high-dose chemotherapy (including methotrexate 8 g/m²) and continuous treatment with alectinib and VBL.

CONCLUSION

Alectinib showed significant and durable CNS effects in this patient. However, more cases are needed to prove the efficacy and safety of alectinib for pediatric ALK+ALCL patients.

Muscular involvement of extranodal natural killer/T cell lymphoma misdiagnosed as polymyositis: A case report and review of literature

BACKGROUND

Natural killer (NK)/T cell lymphoma is a rare and highly aggressive malignant tumor, and is a special form of non-Hodgkin's lymphoma. Although extranodal involvement is frequently found in tissues such as the skin, testicular and gastrointestinal tract etc, its presence in skeletal muscle has scarcely been reported in the literature.

CASE SUMMARY

We report a case of extranodal NK/T cell lymphoma with muscle swelling as the first clinical manifestation. A 42-year-old man, who initially presented with localized swelling in the double lower extremities, demonstrated gradual facial and eyelid swelling, and his imaging results showed multiple sites of muscle damage throughout the body. The final pathological results suggested NK/T cell lymphoma, and immunohistochemistry showed CD20 (-), CD3Ɛ (+), CD30 (+), CD56 (-), EBER (+), Ki67 (60%), TIA-1 (+) and CD68 (±) staining. The muscle swelling significantly improved after treatment with chemotherapy regimens.

CONCLUSION

This disease is difficult to diagnose and highly invasive, and should be included in the differential diagnosis of unexplained muscle swelling.

Transient transfection of serum-free suspension HEK 293 cell culture for efficient production of human rFVIII

Background

Hemophilia A is a bleeding disorder caused by deficiency in coagulation factor VIII. Recombinant factor VIII (rFVIII) is an alternative to plasma-derived FVIII for the treatment of hemophilia A. However, commercial manufacturing of rFVIII products is inefficient and costly and is associated to high prices and product shortage, even in economically privileged countries. This situation may be solved by adopting more efficient production methods. Here, we evaluated the potential of transient transfection in producing rFVIII in serum-free suspension HEK 293 cell cultures and investigated the effects of different DNA concentration (0.4, 0.6 and 0.8 μg/10⁶ cells) and repeated transfections done at 34° and 37°C.

Results

We observed a decrease in cell growth when high DNA concentrations were used, but no significant differences in transfection efficiency and in the biological activity of the rFVIII were noticed. The best condition for rFVIII production was obtained with repeated transfections at 34°C using 0.4 μg DNA/10⁶ cells through which almost 50 IU of active rFVIII was produced six days post-transfection.

Conclusion

Serum-free suspension transient transfection is thus a viable option for high-yield-rFVIII production. Work is in progress to further optimize the process and validate its scalability.

Generation and phenotypic analysis of a transgenic line of rabbits secreting active recombinant human erythropoietin in the milk

Production of recombinant human erythropoietin (rhEPO) for therapeutic purposes relies on its expression in selected clones of transfected mammalian cells. Alternatively, this glycoprotein can be produced by targeted secretion into the body fluid of transgenic mammals. Here, we report on the generation of a transgenic rabbits producing rhEPO in the lactating mammary gland. Transgenic individuals are viable, fertile and transmit the rhEPO gene to the offspring. Northern blot data indicated that the expression of the transgene in the mammary gland is controlled by whey acidic protien (WAP) regulatory sequences during the period of lactation. While the hybridization with total RNA revealed the expression only in the lactating mammary gland, the highly sensitive combinatory approach using RT-PCR/hybridization technique detected a minor ectopic expression. The level of rhEPO secretion in the founder female, measured in the period of lactation, varied in the range of 60-178 and 60-162 mIU/ml in the milk and blood plasma, respectively. Biological activity of the milk rhEPO was confirmed by a standard [3H]-thymidine incorporation test. Thus, we describe the model of a rhEPO-transgenic rabbit, valuable for studies of rhEPO glycosylation and function, which can be useful for the development of transgenic approaches designed for the preparation of recombinant proteins by alternative biopharmaceutical production.