You will be shown a paragraph from a biomedical research article. Your task is to extract all drug combinations appearing in a specific sentence within in the paragraph. Each drug combination should be assigned to one of the following three categories:

- POS: Indicates a positive interaction between the drugs in the combination; for instance, drugs that have an additive or synergistic effect.
- NEG: Indicates a negative interaction between the drugs in the combination; for instance, combining these drugs might result in adverse side effects, or might reduce their efficacy.
- COMB: Indicates that the drugs are given in combination, but the type of interaction between the drugs cannot be determined based on the provided context.

Please format your answer as a json array. Each entry in the array should itself be an array formatted as [<drug_1>, <drug_2>, ..., <drug_n>, <category>] where <category> is one of the three categories listed above and <drug_1>, ..., <drug_n> are drug names copied verbatim from the input sentence. Different combinations may involve different numbers of drugs; in other words, the `n` in <drug_n> may vary.

As an example, the following output describes two extracted drug combinations; one between two drugs, and one between three drugs:

[["artesunate", "artemether", "COMB"], ["Nifedipine", "Labetalol", "Prazosin", "POS"]]

The paragraph and specific sentence are below. You should only extract relationships expressed in the specific sentence; the paragraph is provided for context.

In your output, return only the json array and no other text. If no drug combinations appear, return an empty array `[]`.

paragraph: Induction of drug resistance in human rhabdomyosarcoma cell lines is associated with increased maturation: possible explanation for differentiation in recurrences? In rhabdomyosarcoma (RMS) of childhood and adolescence very little is known about interactions of cytotoxic drugs and tumor cells. In recurrent RMS the tumor cells are often more mature than in the primary tumor. The biological properties of these cells are still a subject of controversy. We investigated two human ( RD2 and TE 671 ) cell lines by cultivating them with doxorubicin , cisplatinum , and etoposide . Degree of differentiation and proliferation rate were estimated morphologically and by means of immunohistochemistry and a monolayer proliferation assay. Both morphological and immunohistochemical maturation was measurable in most resistant cell lines. An increase in myosin expression was most marked in the etoposide- and doxorubicin-resistant RD cell lines. The proliferation rate was decreased in almost all resistant cell lines. Nevertheless, the resistant cell lines tolerated high-dose levels of cytotoxic drugs at a higher proliferation rate than parental cell lines cultivated under similar conditions. The maturation seen in some recurrent tumors of RMS can be simulated in vitro by cultivating cell lines with cytotoxic drugs at sublethal doses. Interestingly, the resistance-associated induced maturation was not accompanied by p170 expression. After comparing these in vitro results with the maturation seen in RMS specimens after chemotherapy, we conclude that chemotherapy-induced differentiation in vivo might be a morphological sign of chemoresistance.

sentence: We investigated two human ( RD2 and TE 671 ) cell lines by cultivating them with doxorubicin , cisplatinum , and etoposide .
[["doxorubicin", "etoposide", "cisplatinum", "COMB"]]